What are metaxalone 800 mg. Metaxalone 800mg: Uses, Side Effects, and Interactions of This Muscle Relaxant
What is metaxalone 800mg used for. How does metaxalone work to relieve muscle pain. What are the potential side effects of taking metaxalone. How does metaxalone interact with other medications. When should you avoid taking metaxalone 800mg. What precautions should be taken when using this muscle relaxant.
Understanding Metaxalone: A Powerful Muscle Relaxant
Metaxalone, commonly known by its brand name Skelaxin, is a centrally acting skeletal muscle relaxant. It belongs to the class of drugs called spasmolytics, which are primarily used to alleviate muscle spasms and associated pain. The 800mg dosage is the most commonly prescribed strength for this medication.
This drug works by depressing the central nervous system, specifically targeting the spinal cord and subcortical areas of the brain. By doing so, it helps to reduce muscle tension and pain without directly acting on the muscles themselves.
Primary Uses of Metaxalone 800mg
Metaxalone is primarily prescribed for the following conditions:
- Acute, painful musculoskeletal conditions
- Muscle spasms
- Lower back pain
- Neck pain
- Tension headaches
Is metaxalone effective for all types of muscle pain. While it’s highly effective for acute conditions, it’s important to note that metaxalone is not typically recommended for chronic pain management or for conditions like fibromyalgia. Its use is generally short-term, aimed at providing relief while the underlying condition improves.
The Pharmacology of Metaxalone: How It Works in Your Body
Understanding how metaxalone works in the body can help patients better appreciate its effects and potential side effects. Unlike some other muscle relaxants, metaxalone doesn’t directly affect the muscles. Instead, it works on the central nervous system to reduce pain signals and muscle tension.
Mechanism of Action
The exact mechanism of action for metaxalone is not fully understood. However, researchers believe it works by:
- Depressing nerve impulses in the spinal cord
- Reducing pain sensation in the brain
- Inhibiting polysynaptic reflex arcs involved in producing and maintaining skeletal muscle spasm
Does metaxalone cause drowsiness like other muscle relaxants. While it can cause drowsiness, metaxalone is generally considered to have less sedative effects compared to other muscle relaxants like carisoprodol or cyclobenzaprine. This makes it a preferred choice for patients who need to remain alert during the day.
Dosage and Administration of Metaxalone 800mg
The typical dosage of metaxalone for adults is 800mg taken three to four times daily. However, the exact dosage may vary depending on the individual’s condition, response to treatment, and other factors.
Important Administration Guidelines
When taking metaxalone, patients should follow these guidelines:
- Take the medication with food to increase its absorption and effectiveness
- Do not crush or chew the tablets; swallow them whole with a full glass of water
- Avoid alcohol while taking metaxalone, as it can increase the risk of side effects
- Do not exceed the prescribed dosage or duration of treatment
Can metaxalone be taken on an empty stomach. While it’s possible to take metaxalone on an empty stomach, taking it with food significantly increases its bioavailability. This means more of the drug is absorbed and utilized by the body, potentially leading to better therapeutic effects.
Potential Side Effects and Risks of Metaxalone 800mg
Like all medications, metaxalone can cause side effects. While not everyone experiences these, it’s important to be aware of potential adverse reactions.
Common Side Effects
The most frequently reported side effects of metaxalone include:
- Drowsiness or dizziness
- Headache
- Nausea or vomiting
- Irritability
- Nervousness
- Dry mouth
Are there any serious side effects associated with metaxalone. While rare, some patients may experience more severe side effects such as:
- Allergic reactions (rash, itching, swelling)
- Jaundice (yellowing of the skin or eyes)
- Unusual bleeding or bruising
- Severe dizziness or fainting
- Mental/mood changes
If any of these serious side effects occur, patients should seek immediate medical attention.
Drug Interactions: What to Watch Out for When Taking Metaxalone
Metaxalone can interact with various other medications, potentially altering their effectiveness or increasing the risk of side effects. It’s crucial for patients to inform their healthcare provider about all medications, supplements, and herbal products they are taking.
Notable Drug Interactions
Some of the significant drug interactions with metaxalone include:
- CNS depressants (e.g., alcohol, benzodiazepines, opioids): Can increase sedation and impairment
- CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): May increase metaxalone levels in the body
- CYP3A4 inducers (e.g., rifampin, carbamazepine): May decrease metaxalone effectiveness
- Drugs affecting liver enzymes: Can alter metaxalone metabolism
How does metaxalone interact with other muscle relaxants. Combining metaxalone with other muscle relaxants is generally not recommended as it can significantly increase the risk of side effects, particularly excessive sedation and respiratory depression.
Precautions and Contraindications for Metaxalone Use
While metaxalone is generally well-tolerated, there are certain situations where its use may be contraindicated or require extra caution.
Who Should Avoid Metaxalone?
Metaxalone should be avoided or used with extreme caution in patients with:
- Known hypersensitivity to metaxalone or any of its components
- Severe liver disease
- Significant kidney impairment
- History of drug abuse or addiction
- Pregnancy or breastfeeding (unless benefits clearly outweigh risks)
Is it safe to drive while taking metaxalone. Patients should avoid driving or operating heavy machinery until they know how metaxalone affects them. Even if drowsiness is not experienced, the drug can still impair reaction times and coordination.
Comparing Metaxalone to Other Muscle Relaxants
Metaxalone is one of several muscle relaxants available for treating musculoskeletal conditions. Understanding how it compares to other options can help patients and healthcare providers make informed decisions about treatment.
Metaxalone vs. Cyclobenzaprine
Cyclobenzaprine (Flexeril) is another commonly prescribed muscle relaxant. Here’s how they compare:
- Sedation: Metaxalone generally causes less sedation than cyclobenzaprine
- Duration: Cyclobenzaprine has a longer half-life, potentially leading to longer-lasting effects
- Anticholinergic effects: Cyclobenzaprine has more pronounced anticholinergic effects (dry mouth, constipation, etc.)
- Efficacy: Both are considered similarly effective for acute muscle spasms
Which muscle relaxant is best for lower back pain. The choice between metaxalone and other muscle relaxants often depends on individual patient factors, including the specific cause of pain, potential side effects, and other medications the patient is taking. Some studies suggest that metaxalone may have a slightly better side effect profile for treating lower back pain compared to other options.
Managing Potential Risks: Tips for Safe Use of Metaxalone 800mg
To maximize the benefits of metaxalone while minimizing potential risks, patients should follow these guidelines:
- Always take metaxalone exactly as prescribed by your healthcare provider
- Inform your doctor about all other medications, supplements, and herbal products you’re using
- Avoid alcohol and other CNS depressants while taking metaxalone
- Do not suddenly stop taking metaxalone without consulting your doctor, as this may lead to withdrawal symptoms
- Be cautious when performing activities requiring alertness until you know how the medication affects you
- Store metaxalone at room temperature, away from moisture and heat
- Keep regular follow-up appointments with your healthcare provider to monitor your progress and any potential side effects
Can metaxalone be used long-term for chronic pain conditions. Metaxalone is generally not recommended for long-term use in managing chronic pain. It’s primarily intended for short-term relief of acute muscle spasms and associated pain. For chronic conditions, other treatment modalities such as physical therapy, exercise, or different classes of medications may be more appropriate.
Monitoring for Adverse Effects
Patients taking metaxalone should be vigilant for any unusual symptoms or side effects. Some signs that warrant immediate medical attention include:
- Severe dizziness or fainting
- Unusual changes in mood or behavior
- Signs of liver problems (e.g., persistent nausea/vomiting, loss of appetite, dark urine, yellowing of eyes/skin)
- Allergic reactions (rash, itching, swelling, severe dizziness, difficulty breathing)
Regular blood tests may be recommended to monitor liver function, especially for patients on long-term therapy or those with pre-existing liver conditions.
Metaxalone – an overview | ScienceDirect Topics
Muscle Relaxants
Muscle relaxants decrease muscle tone and are used to relieve symptoms such as muscle spasms, cramping, hyperreflexia, tension headaches, neck pain, lower back pain, fibromyalgia, and myofascial pain syndrome. There are two main groups of muscle relaxants: neuromuscular blockers which have no CNS activity, and spasmolytics which are almost all centrally acting. Examples of commonly prescribed spasmolytics include carisoprodol (e.g., Soma® and Sanoma®), cyclobenzaprine (e.g., Flexeril® and Amrix®), metaxalone (e.g., Skelaxin®), methocarbamol (e.g., Robaxin®), tizanidine (e.g., Zanaflex®), baclofen (e.g., Lioresal® and Liofen®), and dantrolene (e.g., Dantrium®). Dantrolene is a peripherally acting muscle relaxant with no CNS activity. Off-label use of the anticonvulsant drug gabapentin (e.g., Neurontin®) includes the treatment of restless leg syndrome and the lessening of pain and spasticity in multiple sclerosis.
Carisoprodol is a centrally acting skeletal muscle relaxant commonly prescribed for the treatment of acute musculoskeletal pain. It is available in tablet form either on its own or in combination with aspirin or codeine. Meprobamate is the primary metabolite of carisoprodol; however, it is also a CNS depressant in its own right (Miltown® and Equanil®) and is indicated for the management of anxiety disorders and for short-term treatment of anxiety symptoms. Both carisoprodol and meprobamate are frequently prescribed with other drugs such as opiates and benzodiazepines to control chronic pain.
Following therapeutic use, the effects of carisoprodol begin within 30 min and last for up to 4–6 h. Meprobamate has a much longer duration of effect and drug accumulation may occur during chronic therapy. Unwanted effects are common with both drugs and include dizziness, drowsiness, disorientation, unsteadiness, slurred speech, ataxia, and tremor. Patients also have a tendency to doze off or fall asleep. In higher doses, patients may experience intoxication or drunken behavior, loss of balance and coordination, weakness, agitation, disorientation to place and time, and sleep disturbances. In abuse or overdose, patients may be consistently sedated and even become comatose. Overdose symptoms can include shallow breathing, clammy skin, weak and rapid pulse, paradoxical insomnia, convulsions, severe respiratory depression, and possibly death.
Following chronic use of either drug, development of abuse and moderate physical and psychological dependence can occur. Abrupt discontinuation after long-term use can result in mild withdrawal symptoms such as anxiety, abdominal cramps, insomnia, vomiting, muscle twitching, confusion, and occasionally chills, convulsions, and hallucinations.
Skelaxin (metaxalone) dosing, indications, interactions, adverse effects, and more
Serious – Use Alternative (1)abametapir will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.
Monitor Closely (1)abiraterone increases levels of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.
Monitor Closely (1)metaxalone increases effects of abobotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
Monitor Closely (1)metaxalone and alfentanil both increase sedation. Use Caution/Monitor.
Monitor Closely (1)alprazolam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and amitriptyline both increase sedation. Use Caution/Monitor.
Monitor Closely (2)amobarbital will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
amobarbital and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and amoxapine both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)apalutamide will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.
Monitor Closely (1)metaxalone and apomorphine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and aripiprazole both increase sedation. Use Caution/Monitor.
Monitor Closely (1)azelastine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)baclofen and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and belladonna and opium both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and benperidol both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)benzhydrocodone/acetaminophen, metaxalone.
Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
Monitor Closely (1)metaxalone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Monitor Closely (1)brexanolone, metaxalone.
Either increases toxicity of the other by sedation. Use Caution/Monitor.
Monitor Closely (1)brompheniramine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and buprenorphine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and buprenorphine buccal both increase sedation. Use Caution/Monitor.
Monitor Closely (1)buprenorphine, long-acting injection increases effects of metaxalone by Other (see comment). Modify Therapy/Monitor Closely.
Comment: Buprenorphine may enhance the neuromuscular blocking action of skeletal muscle relaxants and increase risk for respiratory depression. Monitor for signs of respiratory depression that may be greater than otherwise expected and decrease muscle relaxant dosage as necessary.
Monitor Closely (1)butabarbital and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)butalbital and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and butorphanol both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)metaxalone, calcium/magnesium/potassium/sodium oxybates.
Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
Monitor Closely (1)cannabidiol, metaxalone. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.
Monitor Closely (1)carbinoxamine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)carisoprodol and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)cenobamate will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.
Monitor Closely (1)chloral hydrate and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)chlordiazepoxide and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)chlorpheniramine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and chlorpromazine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)chlorzoxazone and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)cinnarizine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)clemastine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone, clobazam. Other (see comment). Use Caution/Monitor.
Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).
Monitor Closely (1)metaxalone and clomipramine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)clonazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)clorazepate and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and clozapine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and codeine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)crofelemer increases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.
Monitor Closely (1)cyclizine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)cyclobenzaprine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)cyproheptadine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)dabrafenib will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
Monitor Closely (1)dantrolene and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and desipramine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)dexchlorpheniramine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Monitor Closely (1)dexmedetomidine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and dextromoramide both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and diamorphine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)diazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)diazepam intranasal, metaxalone.
Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.
Monitor Closely (1)metaxalone and difenoxin hcl both increase sedation. Use Caution/Monitor.
Monitor Closely (1)dimenhydrinate and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)diphenhydramine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and dipipanone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Monitor Closely (1)metaxalone and dosulepin both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and doxepin both increase sedation. Use Caution/Monitor.
Monitor Closely (1)doxylamine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and droperidol both increase sedation. Use Caution/Monitor.
Monitor Closely (1)efavirenz will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
Monitor Closely (1)elagolix decreases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.
Monitor Closely (2)elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
Monitor Closely (1)encorafenib, metaxalone. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.
Monitor Closely (1)esketamine intranasal, metaxalone.
Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.
Monitor Closely (1)estazolam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and ethanol both increase sedation. Use Caution/Monitor.
Monitor Closely (1)etomidate and metaxalone both increase sedation. Use Caution/Monitor.
Minor (1)metaxalone and eucalyptus both increase sedation. Minor/Significance Unknown.
Monitor Closely (1)fedratinib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
Monitor Closely (1)metaxalone increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Serious – Use Alternative (1)fexinidazole will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.
Monitor Closely (1)metaxalone and fluphenazine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)flurazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and haloperidol both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)hydrocodone, metaxalone.
Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
Monitor Closely (1)metaxalone and hydromorphone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)hydroxyzine and metaxalone both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)idelalisib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates
Monitor Closely (2)metaxalone and iloperidone both increase sedation. Use Caution/Monitor.
iloperidone increases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4.
Monitor Closely (1)metaxalone and imipramine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone, incobotulinumtoxinA.
Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
Monitor Closely (1)istradefylline will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.
Serious – Use Alternative (1)ivosidenib will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternative therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.
Monitor Closely (1)ketamine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
Monitor Closely (1)lasmiditan, metaxalone.
Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.
Monitor Closely (1)lemborexant, metaxalone.
Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.
Monitor Closely (1)metaxalone and levorphanol both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and lofepramine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and lofexidine both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)lopinavir will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
Monitor Closely (1)loprazolam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)lorazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)lorcaserin will increase the level or effect of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
Monitor Closely (1)lormetazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and loxapine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and loxapine inhaled both increase sedation. Use Caution/Monitor.
Monitor Closely (1)lurasidone, metaxalone.
Either increases toxicity of the other by Other (see comment). Use Caution/Monitor.
Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.
Monitor Closely (1)metaxalone and maprotiline both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and marijuana both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and melatonin both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and meperidine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and meprobamate both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and methadone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and methocarbamol both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Serious – Use Alternative (1)metaxalone, metoclopramide intranasal.
Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug.
Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
Monitor Closely (1)midazolam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Monitor Closely (1)mifepristone will increase the level or effect of metaxalone by Other (see comment). Use Caution/Monitor. Inhibits CYP2C8/2C9; use smallest recommended doses for substrates and monitor
Monitor Closely (1)mirabegron will increase the level or effect of metaxalone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
Monitor Closely (1)metaxalone and mirtazapine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)mitotane decreases levels of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.
Monitor Closely (1)metaxalone and morphine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and motherwort both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and moxonidine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and nabilone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and nalbuphine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)nefazodone will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
Monitor Closely (1)metaxalone and nortriptyline both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and olanzapine both increase sedation. Use Caution/Monitor.
Monitor Closely (2)oliceridine, metaxalone.
Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
metaxalone increases toxicity of oliceridine by Other (see comment). Modify Therapy/Monitor Closely.
Comment: Anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Monitor for signs of urinary retention or reduced gastric motility if oliceridine is coadministered with anticholinergics.
Monitor Closely (1)metaxalone and opium tincture both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and orphenadrine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)oxazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and oxycodone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and oxymorphone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and paliperidone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and papaveretum both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and papaverine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and pentazocine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)pentobarbital and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and perphenazine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)phenobarbital and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
Monitor Closely (1)metaxalone and pholcodine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and pimozide both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases effects of prabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Muscle relaxants may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.
Monitor Closely (1)primidone and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and prochlorperazine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)promethazine and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)propofol and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Monitor Closely (1)metaxalone and protriptyline both increase sedation. Use Caution/Monitor.
Monitor Closely (1)quazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and quetiapine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and ramelteon both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone increases effects of remifentanil by pharmacodynamic synergism. Modify Therapy/Monitor Closely. CNS depressant effect increased.
Monitor Closely (1)remimazolam, metaxalone.
Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.
Minor (1)ribociclib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
Monitor Closely (1)metaxalone and risperidone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)rucaparib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.
Minor (1)metaxalone and sage both increase sedation. Minor/Significance Unknown.
Monitor Closely (1)metaxalone and scullcap both increase sedation. Use Caution/Monitor.
Monitor Closely (1)secobarbital and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and shepherd’s purse both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)metaxalone, sodium oxybate.
Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
Monitor Closely (2)stiripentol, metaxalone.
Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.
stiripentol, metaxalone. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
Monitor Closely (1)metaxalone and sufentanil both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)sufentanil SL, metaxalone.
Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
Monitor Closely (1)metaxalone and tapentadol both increase sedation. Use Caution/Monitor.
Monitor Closely (1)tazemetostat will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
Monitor Closely (1)tecovirimat will decrease the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.
Monitor Closely (1)temazepam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (2)teriflunomide increases levels of metaxalone by Other (see comment). Use Caution/Monitor.
Comment: Teriflunomide inhibits CYP2C8; caution when coadministered with CYP2C8 substrates.
teriflunomide decreases levels of metaxalone by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
Monitor Closely (1)metaxalone and thioridazine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and thiothixene both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and topiramate both increase sedation. Modify Therapy/Monitor Closely.
Monitor Closely (1)metaxalone and tramadol both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and trazodone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)triazolam and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)triclofos and metaxalone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and trifluoperazine both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and trimipramine both increase sedation. Use Caution/Monitor.
Serious – Use Alternative (1)tucatinib will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.
Serious – Use Alternative (1)voxelotor will increase the level or effect of metaxalone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.
Monitor Closely (1)metaxalone increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Monitor Closely (1)metaxalone and ziconotide both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and ziprasidone both increase sedation. Use Caution/Monitor.
Monitor Closely (1)metaxalone and zotepine both increase sedation. Use Caution/Monitor.
Differences, similarities, and which is better for you
Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ
Have you ever “thrown out your back” or experienced an injury or sprain where you feel like your muscles are spasming and so tight that you can’t move? If so, your healthcare provider may have prescribed a muscle relaxant to help your symptoms.
Skelaxin and Flexeril are two FDA-approved medications indicated to treat muscle spasms. They are in a group of medications called skeletal muscle relaxants. Skelaxin and Flexeril are most commonly prescribed as their generic counterparts, metaxalone and cyclobenzaprine. The way they work is not completely understood, but may be due to central nervous system (CNS) depression and sedative effects. These medications do not act directly on the muscle or nerves.
Although both medications are muscle relaxants, they are not exactly the same. Continue reading below to learn more about Skelaxin and Flexeril.
What are the main differences between Skelaxin and Flexeril?
Skelaxin is a skeletal muscle relaxant that contains metaxalone. It is available in brand and generic tablets. Skelaxin is used for short-term treatment.
Flexeril is also a skeletal muscle relaxant—the active ingredient is cyclobenzaprine. Flexeril is no longer available commercially as a brand-name product. Flexeril is only available as its generic, cyclobenzaprine. Cyclobenzaprine is also available in an extended-release form with the brand name of Amrix. Flexeril is used for short-term treatment—the manufacturer’s information recommends that Flexeril should not be taken for more than two or three weeks.
Main differences between Skelaxin and Flexeril | ||
---|---|---|
Drug class | Skeletal muscle relaxant | Skeletal muscle relaxant |
Brand/generic status | Brand and generic | Flexeril: available in generic only Amrix: available in brand and generic |
What is the generic name? | Metaxalone | Cyclobenzaprine |
What form(s) does the drug come in? | Tablet | Tablet, extended-release capsule (brand name Amrix) |
What is the standard dosage? | The recommended dose is one (800 mg) tablet or two (400 mg) tablets 3 to 4 times daily | The recommended dose is one tablet (5 mg or 10 mg) 3 times daily Or One tablet (5 mg, 7.5 mg, or 10 mg) at bedtime (less frequent dosing for patients with liver problems or elderly patients) |
How long is the typical treatment? | Short-term | Short-term (not recommended for more than 2-3 weeks) |
Who typically uses the medication? | Adults and children over age 12 years | Adults and children age 15 years and older |
Conditions treated by Skelaxin and Flexeril
Skelaxin and Flexeril are both indicated to be used along with rest, physical therapy, and other measures to relieve the discomfort of acute, painful musculoskeletal conditions like acute low back pain or neck pain.
Both drugs may be prescribed off-label for other conditions, but they are primarily used for muscle spasms. Also, the Flexeril manufacturer information states that the drug is not effective for spasticity associated with cerebral or spinal cord disease, or in children with cerebral palsy.
Acute, painful musculoskeletal conditions | Yes | Yes |
Fibromyalgia | Off-label | Off-label |
Tension headache | Off-label | Off-label |
Insomnia | Off-label | Off-label |
Acute jaw pain from TMJ | Off-label | Off-label |
Is Skelaxin or Flexeril more effective?
American Family Physician states that there is weak (and very little) evidence in terms of muscle relaxants and their efficacy compared to each other. They recommend that the selection of a muscle relaxant should be based on the potential for side effects, drug interactions, abuse, and also patient preference. This publication also reiterates the importance of short-term use of muscle relaxants and that physical therapy and other measures should be taken to prevent long-term use of a muscle relaxant. Other medications such as Tylenol (acetaminophen) or nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may also be used.
Your healthcare provider can determine if Skelaxin or Flexeril is appropriate for you. He or she will consider your symptoms, medical conditions, medical history, and any medications you take that may interact with Skelaxin or Flexeril.
Coverage and cost comparison of Skelaxin vs. Flexeril
Most insurance plans typically cover Skelaxin in its generic form of metaxalone. Medicare Part D coverage varies. A typical prescription of generic Skelaxin would have an out-of-pocket cost of $147, but you can use a SingleCare coupon to bring the price down to less than $50.
Most insurance and Medicare Part D plans cover Flexeril (generic). Brand-name Flexeril is not available. A typical prescription of generic Flexeril would cost about $20 out-of-pocket, but with SingleCare you can purchase the generic Flexeril for about $7-$8 at participating pharmacies.
Typically covered by insurance? | Yes (generic) | Yes (generic) |
Typically covered by Medicare Part D? | No | Yes (generic) |
Standard dosage | 30, 800 mg tablets | 30, 10 mg tablets |
Typical Medicare copay | $1-$54, depending on the specific plan | $0-$1 |
SingleCare cost | $48+ | $7+ |
Common side effects of Skelaxin vs. Flexeril
Both drugs can be very sedating. Skelaxin’s most common side effects are drowsiness, dizziness, headache, irritability, nausea, vomiting, and stomach upset.
The most common side effects of Flexeril are drowsiness, dizziness, headache, and dry mouth.
With either drug, an allergic reaction is rare but possible. Serotonin syndrome, a life-threatening condition due to serotonin buildup, is also possible.
Side effect | Applicable? | Frequency | Applicable? | Frequency |
Drowsiness | Yes | Not reported | Yes | 29-38%* |
Dizziness | Yes | Not reported | Yes | 11% |
Headache | Yes | Not reported | Yes | 5% |
Irritability | Yes | Not reported | Yes | 1-3% |
Nausea | Yes | Not reported | Yes | 1-3% |
Vomiting | Yes | Not reported | Yes | 1-3% |
Stomach upset | Yes | Not reported | Yes | 1-3% |
Dry mouth | No | – | Yes | 21-32% |
*Side effect percentages of Flexeril depend on the dose
Source: DailyMed (Skelaxin), DailyMed (Flexeril)
Drug interactions of Skelaxin vs. Flexeril
Skelaxin and Flexeril can potentiate the effects of alcohol, barbiturates, and other CNS depressants, such as benzodiazepines, opioids, antihistamines, and sedative-hypnotics.
There is an increased risk of serotonin syndrome when Skelaxin or Flexeril is taken with other drugs that increase serotonin; such as SSRI, SNRI, or tricyclic antidepressants; triptans for migraine; or cough and cold medications that contain dextromethorphan.
Flexeril is structurally similar to tricyclic antidepressants (such as amitriptyline and nortriptyline). Because of this, there is an increased risk of seizures when taken with tramadol.
Both Skelaxin and Flexeril interact with tramadol (and other opioids)—there is an increased risk of serotonin syndrome as well as additive CNS depression.
This is not a full list of drug interactions. Consult your healthcare provider for medical advice regarding drug interactions.
Alcohol | Alcohol | Yes | Yes |
Pentobarbital Phenobarbital | Barbiturates | Yes | Yes |
Alprazolam Clonazepam Diazepam Lorazepam Temazepam | Benzodiazepines | Yes | Yes |
Eszopiclone Zaleplon Zolpidem | Sedative hypnotics | Yes | Yes |
Codeine Fentanyl Hydrocodone Hydromorphone Methadone Morphine Oxycodone Tramadol | Opioids | Yes | Yes |
Phenelzine Selegiline Tranylcypromine | MAO Inhibitors | Yes | |
Cetirizine Diphenhydramine | Antihistamines | Yes | Yes |
Citalopram Escitalopram Fluoxetine Fluvoxamine Paroxetine Sertraline | SSRI antidepressants | Yes | Yes |
Desvenlafaxine Duloxetine Venlafaxine | SNRI antidepressants | Yes | Yes |
Amitriptyline Desipramine Imipramine Nortriptyline | Tricyclic antidepressants | Yes | Yes |
Almotriptan Eletriptan Sumatriptan Zolmitriptan | Triptans | Yes | Yes |
Delsym Phenergan-DM Robitussin-DM Tussin-DM | OTC/Rx cough products that contain dextromethorphan | Yes | Yes |
Warnings of Skelaxin and Flexeril
Skelaxin
- Use Skelaxin with caution in elderly patients and patients with liver or kidney problems or anemia.
- Taking Skelaxin with food may significantly increase the CNS depression effect. Elderly patients are more susceptible to this effect.
Flexeril
- Do not take an MAO inhibitor within 14 days of Flexeril—the combination could cause seizures and death.
- Patients with hyperthyroidism, heart failure, or other heart or rhythm problems should not take Flexeril. Use Flexeril with caution in elderly patients and patients with liver problems. Do not use the extended-release form (Amrix) in patients with liver problems.
- Use Flexeril with caution in patients with a history of urinary retention, angle-closure glaucoma, increased intraocular pressure, and in patients taking anticholinergic medication.
- Consider withdrawal symptoms when discontinuing Flexeril. Stopping the medicine too quickly may cause headaches, fatigue, and nausea.
- Swallow Amrix (extended-release cyclobenzaprine) capsules whole. Do not chew or crush.
Skelaxin and Flexeril warnings in common
- Both medications are on the list of Beers criteria, meaning that they are potentially inappropriate for older adults (age 65 and older). Most older adults do not tolerate muscle relaxants well due to serious side effects, sedation, and increased risk of fractures. Also, the effectiveness is questionable at the doses that may be tolerated in this age group.
- Overdose deaths (deliberate or accidental) have occurred from Skelaxin or Flexeril, especially in combination with antidepressants or alcohol. Monitor patients closely.
- Serotonin syndrome may occur. Patients and their caregivers should be aware of the symptoms (sweating, fever, agitation, change in blood pressure or heart rate, tremor, nausea, vomiting, diarrhea) and seek immediate medical attention if symptoms occur. Serotonin syndrome is more likely to occur if you take Skelaxin or Flexeril in combination with other drugs that increase serotonin, such as certain antidepressants, triptans, or cough and cold preparations that contain dextromethorphan.
- Do not drive or operate machinery until you know how you react to Skelaxin or Flexeril. Both drugs cause drowsiness and dizziness.
Frequently asked questions about Skelaxin vs. Flexeril
What is Skelaxin?
Skelaxin is a skeletal muscle relaxant used for the acute treatment of muscle spasms. The generic name for Skelaxin is metaxalone.
What is Flexeril?
Flexeril is also a muscle relaxant used to treat skeletal muscle spasms. The generic name of Flexeril is cyclobenzaprine.
Are Skelaxin and Flexeril the same?
Although Skelaxin and Flexeril are both in the same drug category (skeletal muscle relaxants), they do have some differences, such as side effects, dose, and pricing, as outlined above.
Is Skelaxin or Flexeril better?
No data directly compares the two drugs in terms of pain relief. Therefore, if you need a muscle relaxant, your healthcare provider will consider your symptoms, conditions, and any medications you take (that could interact with Skelaxin or Flexeril) to determine if one of these drugs is better for you.
Can I use Skelaxin or Flexeril while pregnant?
The Skelaxin manufacturer information states, “Post-marketing experience has not revealed evidence of fetal injury, but such experience cannot exclude the possibility of infrequent or subtle damage to the human fetus. Safe use of metaxalone has not been established with regard to possible adverse effects upon fetal development.” Therefore, Skelaxin is not recommended for use in pregnant women (especially in early pregnancy) or women who may become pregnant, unless your healthcare provider determines that benefits outweigh risks.
The Flexeril manufacturer information states that there are no adequate, well-controlled studies in pregnant women. Therefore, Flexeril should be used in pregnant women only if clearly needed.
Can I use Skelaxin or Flexeril with alcohol?
No. Using Skelaxin or Flexeril with alcohol can increase the side effects such as dizziness and drowsiness. It can also lead to impaired coordination, which can cause accidents. Also, taking a muscle relaxant with alcohol can increase the chance of abuse or dependence.
Is Skelaxin a strong muscle relaxer?
Any muscle relaxant, including the following list, should be effective in treating acute muscle pain/spasms when used at the proper dose. Consult your healthcare provider for more information.
Does Skelaxin help with pain?
Yes, Skelaxin helps with the pain of acute muscle spasms. The manufacturer recommends using Skelaxin along with rest, physical therapy, and other measures. The way it works is not entirely understood but is likely due to central nervous system depression. Skelaxin does not directly work on the muscles or nerves.
Is Skelaxin safe?
Like any medication, Skelaxin has benefits as well as side effects and risks. See the Warnings section above for more information. If your healthcare provider has determined that Skelaxin is appropriate for you and is compatible with any medical conditions you have and medications you take, you will likely be able to safely take Skelaxin (for short-term use) with no significant issues. Consult your healthcare provider for medical advice.
Metaxalone | Side Effects | Dosage | Precautions
By Medicover Hospitals / 11 Mar 2021
Home | Medicine | Metaxalone
What is Metaxalone ?
- Metaxalone Uses
- Metaxalone Side effects
- Precautions
- Overdose
- Storage
- Metaxalone vs Tolperisone
- Frequently Asked Questions
- Citations
Metaxalone Uses:
How to use Metaxalone?
Metaxalone Side Effects:
- Drowsiness
- Dizziness
- Upset stomach
- Vomiting
- Headache
- Nervousness
- Severe skin rash
- Difficulty breathing
- Yellowing of the skin or eyes
- Unusual bruising or bleeding
- Unusual tiredness
- Weakness
- Seizures
Precautions:
- Tell your doctor or pharmacist if you are allergic to metaxalone or if you have any other allergies before taking it. Inactive ingredients might be present in this product and can cause allergic reactions or some other problems.
- Inform your doctor or pharmacist about your medical history, particularly if you have: liver disease, kidney disease, anemia, or seizures, before using this medication.
- This medication may cause dizziness or drowsiness. Alcohol can cause dizziness or drowsiness. Do not try driving, operate machinery, or do anything else that requires alertness until you are confident that you can do so safely. Consume no alcoholic beverages.
- Older adults may be more sensitive to the drug’s side effects, particularly dizziness, drowsiness, or confusion. These side effects may increase the likelihood of a fall.
- This medication should be used only when prescribed by your doctor during pregnancy. Consult your doctor about the possible risks and benefits.
- It is not known whether this medication passes through breast milk or not. Before you start breastfeeding, talk to your doctor.
Overdose:
Missed Dose:
Storage:
Metaxalone | Tolperisone |
---|---|
Metaxalone is an analgesic that relaxes the muscles. | Tolperisone Mydocalm) is a centrally-acting skeletal muscle relaxant used to treat increased muscle tone caused by neurological diseases. |
It is used to treat skeletal muscle conditions such as pain or injury in conjunction with rest and physical therapy. | Tolperisone is used to relax muscles. It is employed in the treatment of acute musculoskeletal pain. |
It works by preventing nerve impulses (or pain sensations) from reaching the brain. | It works on the brain and spinal cord centers to relieve muscle stiffness or spasm without reducing strength. This reduces pain and improves muscle movement. |
Frequently Asked Questions:
It is a muscle relaxant that is used to relax the muscles and relieve pain or discomfort caused by strains, sprains, and other muscle injuries in conjunction with rest, physical therapy, and other measures.
This medication may make you dizzy, drowsy, or less alert than usual. These effects may be amplified if you take this medication with food.
Based on clinical studies, metaxalone (Skelaxin) has the fewest reported side effects and the lowest sedation potential of the muscle relaxants when taken as 800 mg tablets three to four times a day. Simply put, it is the most well-tolerated muscle relaxant.
Metaxalone has a 1-hour onset of action, a 2 to 3-hour plasma half-life, and a 4 to 6-hour duration of action. This medication is available in 400-mg tablets with a recommended dose of 800 mg three or four times daily.
It works for sohrt-term relief of low back pain and is equally effective.
Metaxalone is contraindicated in patients with severely impaired hepatic and renal function. Because methylmalonic is metabolized by the liver and then eliminated by the kidney, both the parent drug and its metabolites may accumulate in such patients.
Metaxalone belongs to the drug class skeletal muscle relaxants and is used to treat muscle spasms. The FDA has not classified the drug as safe to use during pregnancy. Under the Controlled Substances Act, metaxalone 800 mg is not a controlled substance.
Skeletal muscle relaxants such as Skelaxin (metaxalone) and Flexeril (cyclobenzaprine) are used to treat painful muscle spasms. Similar Skelaxin and Flexeril side effects include drowsiness, dizziness, headache, nausea, and stomach upset or pain.
Metaxalone is an analgesic that relaxes the muscles. It works by preventing nerve impulses (or pain sensations) from reaching the brain. Metaxalone is used to treat skeletal muscle conditions such as pain or injury in conjunction with rest and physical therapy.
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Metaxalone tablets
What is this medicine?
METAXALONE (me TAX a lone) is a muscle relaxer. It is used to treat pain and stiffness in muscles caused by strains, sprains, or other injury.
This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.
COMMON BRAND NAME(S): Metaxall, Skelaxin
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
- anemia or blood disorder
- kidney disease
- liver disease
- an unusual or allergic reaction to metaxalone, other medicines, foods, dyes, or preservatives
- pregnant or trying to get pregnant
- breast-feeding
How should I use this medicine?
Take this medicine by mouth. Swallow it with a full glass of water. Follow the directions on the prescription label. Do not take more medicine than you are told to take.
Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for children as young as 13 years of age for selected conditions, precautions do apply.
Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What may interact with this medicine?
Do not take this medication with any of the following medicines:
- narcotic medicines for cough
This medicine may also interact with the following medications:
- alcohol
- antihistamines for allergy, cough and cold
- certain medicines for anxiety or sleep
- certain medicines for depression like amitriptyline, fluoxetine, sertraline
- certain medicines for seizures like phenobarbital, primidone
- general anesthetics like halothane, isoflurane, methoxyflurane, propofol
- local anesthetics like lidocaine, pramoxine, tetracaine
- medicines that relax muscles for surgery
- narcotic medicines for pain
- phenothiazines like chlorpromazine, mesoridazine, prochlorperazine, thioridazine
This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.
What should I watch for while using this medicine?
Tell your doctor or health care professional if your symptoms do not start to get better or if they get worse.
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medicine. Avoid alcoholic drinks.
If you are taking another medicine that also causes drowsiness, you may have more side effects. Give your health care provider a list of all medicines you use. Your doctor will tell you how much medicine to take. Do not take more medicine than directed. Call emergency for help if you have problems breathing or unusual sleepiness.
What side effects may I notice from receiving this medicine?
Side effects that you should report to your doctor or health care professional as soon as possible:
- allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
- breathing problems
- unusually weak or tired
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
- anxious
- headache
- irritability
- upset stomach
This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Where should I keep my medicine?
Keep out of the reach of children.
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Keep container tightly closed. Throw away any unused medicine after the expiration date.
NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.
What is Metaxalon?
Metaxalone is a prescription-only muscle relaxant that is most commonly used to treat trauma to the musculoskeletal system that results in pain such as sprains or muscle spasms. The drug is a central nervous system (CNS) depressant and may cause more severe sedative symptoms when combined with other CNS depressants. Doctors do not always consider this medication as the best choice and take into account the patient’s health conditions or prescribed medications that are contraindicated.In addition, metaxalone can cause minor or serious side effects in a small percentage of users.
Metaxalone is available by prescription in most regions and is usually prescribed only to adults or children over 12 years of age. The usual dose is an 800 mg tablet, although less is sometimes recommended, every three to four hours. Younger children are not good candidates for this medication. Elderly patients usually don’t get it either, because CNS effects, such as dizziness, can be much more pronounced in this population.Pregnant and breastfeeding women should also not use this medication.
There are certain medical conditions that may contraindicate the use of metaxalone. Those with anemia – an extremely low red blood cell count – are generally not advised to take this drug. Patients with sick or damaged liver or kidneys may need to use less of the drug or may need other medications to relieve pain.
Drug interactions between metaxalone and other medications are numerous.The main interaction occurs when patients are taking propoxyphene of any kind. However, since many regions have banned the use of propoxyphene, it is less likely that anyone will experience this reaction.
Using this medication with other drugs that are CNS depressants is likely to cause an increase in certain side effects. Those taking benzodiazepines, opioids, barbiturates, or antipsychotic medications should discuss the risks and benefits of taking them with metaxalone with their doctor.In addition, people should avoid mixing the drug with alcohol, which is also a CNS depressant.
The side effects of metaxalone can be considered benign or serious. Some patients develop mild gastrointestinal distress such as vomiting, nausea, or indigestion. Others report rashes or headaches. Symptoms of CNS depression include dizziness and drowsiness, and drug users can also have paradoxical reactions such as anxiety.These side effects are usually benign, but should be reported if they worsen or interfere with daily activities.
In contrast, serious adverse reactions require immediate medical attention. These include any signs of an allergy such as hives, shortness of breath, and swelling of the face, mouth, and tongue. Nausea with severe abdominal pain is a medical emergency, as is the presence of jaundice or fever. Patients should also get help if their urine is very dark, as this may indicate problems with kidney function.
OTHER LANGUAGES
Metaxalone oral administration: uses, side effects, interactions, pictures, warnings and dosing –
Uses
Uses
Metaxalone is used to treat muscle spasms / pain. It is commonly used in conjunction with rest, physical therapy, and other treatments.
How to use Metaxalon
Take this medication by mouth with or without food as directed by your healthcare practitioner, usually 3-4 times a day.If you are taking this medication after a high-fat meal and are experiencing side effects, it is best to take this medication on an empty stomach or after a light meal.
The dosage depends on your medical condition and response to treatment. Do not increase your dose or use this medication more often or for longer than prescribed. Your condition will not improve any faster and your risk of side effects will increase.
Tell your doctor if your condition does not improve or if it worsens.
Related Links
What conditions does Metaxalon treat?
Side effects
Side effects
Drowsiness, dizziness, nausea, vomiting, and upset stomach may occur. If any of these effects persist or worsen, tell your doctor or pharmacist right away.
Remember that your doctor prescribed this medication for you because he or she thought the benefit to you was greater than the risk of side effects.Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including: mental / mood changes (such as nervousness, irritability, confusion), signs of infection (such as fever, persistent sore throat), yellowing eyes / skin, unusual tiredness, dark urine.
This medicine can increase serotonin and rarely causes a very serious condition called serotonin syndrome / toxicity.The risk is increased if you are also taking other drugs that increase serotonin levels, so tell your doctor or pharmacist about any drugs you are taking (see Drug Interactions section). Get immediate medical attention if you develop any of the following symptoms: rapid heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea / vomiting / diarrhea, muscle twitching, unexplained fever, unusual agitation / restlessness.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching / swelling (especially of the face / tongue / throat), severe dizziness, trouble breathing.
This is not a complete listing of potential side effects. If you notice other effects not listed above, ask your doctor or pharmacist.
In the USA –
Ask your doctor about side effects. You can report side effects to the FDA by calling 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada – Call your doctor for medical advice about side effects. You can report side effects to Health Canada at 1-866-234-2345.
Related Links
List the side effects of metaxalone by likelihood and severity.
Precautions
Precautions
Before taking metaxalone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients that may cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially about: liver disease, kidney disease, anemia, seizures.
This medicine may make you dizzy or drowsy. Alcohol or marijuana can make you dizzy or drowsy. Do not drive, use machinery, or do anything that requires vigilance until you can do so safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana.
Before surgery, tell your doctor or dentist about all products you use (including prescription, non-prescription, and herbal products).
The elderly may be more sensitive to the side effects of this drug, especially dizziness, drowsiness, or confusion. These side effects can increase your risk of falling.
During pregnancy, this medication should only be used when needed. Discuss the risks and benefits with your doctor.
It is unknown if this drug passes into breast milk. Talk to your doctor before breastfeeding.
Related Links
What should I know about pregnancy, breastfeeding, and prescribing metaxalone to children or the elderly?
interactions
interactions
Drug interactions may alter how your medications work or increase your risk of serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription / over-the-counter drugs and herbal products) and share with your doctor and pharmacist.Do not start, stop, or change the dosage of any medication without your doctor’s approval.
Tell your doctor or pharmacist if you are taking other drugs that cause drowsiness such as opioid pain or cough suppressants (eg codeine, hydrocodone), alcohol, marijuana, sleep or anxiety medications (eg alprazolam, lorazepam, zolpidem) , other muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).
Check the labels on all of your medicines (such as allergies or colds) because they may contain ingredients that cause drowsiness. Ask your pharmacist about the safe use of these products.
The risk of serotonin syndrome / toxicity is increased if you are taking other drugs that increase serotonin levels. Some examples are street drugs like MDMA / ecstasy, St. John’s wort, some antidepressants (like SSRIs like fluoxetine / paroxetine, SNRIs like duloxetine / venlafaxine), and others.The risk of serotonin syndrome / toxicity may be more likely when you start or increase your dose of these drugs.
This medication may interfere with certain lab tests (including certain urine glucose tests), which may cause false test results. Make sure laboratory staff and all of your doctors know you are using this drug.
Related Links
Does Metaxalone interact with other medications?
overdose
overdose
If someone has overdose and has severe symptoms such as fainting or trouble breathing, call 911.If not, contact a Poison Control Center immediately. US residents can call their local poison control center at 1-800-222-1222. Residents of Canada can call the provincial poison control center. Overdose symptoms may include: severe drowsiness.
Notes
Do not share this medicine with others.
This medicine was prescribed for your current condition only. Do not use it later for another medical condition, unless your doctor instructs you to do so.In this case, other medications may be required.
Missed dose
If you miss a dose, take it as soon as you remember. If it is close to your next dose, skip them and resume your normal dosing regimen. Don’t double your dose to catch up.
Storage
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medicines out of the reach of children and pets.
Do not flush medicines down the toilet or pour them down the drain unless directed to do so.Correctly discard this product when it has expired or is no longer needed. Check with your pharmacist or local waste disposal company. Last revised March 2018. Copyright (c) 2018 First Databank, Inc.
Images of metaxalone 800 mg tablets
metaxalone 800 mg tablet
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metaxalone 800 mg tablet metaxalone 800 mg tablet
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metaxalone 800 mg tablet metaxalone 800 mg tablet
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- 90 mg tablet 581 9012 metalon 800 mg tablet 800 mg tablet
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metaxalone 400 mg metaxalone tablet 400 mg tablet
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instructions for use, dosages, composition, analogs, side effects / Pillintrip
and also PATIENT INFORMATION ).
Carcinogenesis, mutagenesis, impaired fertility
The carcinogenic potential of metaxalone has not been determined.
Pregnancy
Reproduction studies in rats have shown no evidence of impaired fertility or fetal damage due to metaxalone. Post-marketing experience has not shown any evidence of fetal injury, but such experience cannot exclude the possibility of rare or subtle damage to the human fetus. The safe use of metaxalone has not been demonstrated with respect to possible adverse effects on fetal development.Therefore, metaxalone tablets should not be used by women who are or may be pregnant, especially during early pregnancy, unless the doctor believes the potential benefits outweigh the potential dangers.
Nursing mothers
It is not known whether this drug is excreted in breast milk. In general, you should not be careful when taking medications, as many medications are excreted in breast milk.
Pediatric use
Safety and efficacy in children over 12 years of age have not been established.
Overdose and Contraindications
TRANSLATION
Intentional or accidental overdose deaths have occurred in metaxalone, especially in combination with antidepressants, and this class of drugs has been reported in combination with alcohol.
Serotonin syndrome has been reported when metaxalone was used at doses above the recommended dose of layers (see WARNINGS ).
In the determination of LD 50 , progressive sedation, hypnosis and finally respiratory failure were found in rats and mice with increasing dosage.No LD can be found in dogs. 50 are determined because higher doses were emetic after 15-30 minutes.
Treatment
Gastric lavage and supportive care. It is recommended that you check with your Regional Gift Management Center.
PRICE
Hypersensitivity to the components of this product is known.
Known tendency towards drug, hemolytic or other anemias.
Significantly impaired renal or liver function.
Clinical Pharmacology
CLINICAL PHARMACOLOGY
Mechanism of Action
The mechanism of action of metaxalone in humans has not been established, but it can be attributed to general depression of the central nervous system.
Metaxalon has no direct effect on the contractile mechanism of the striated muscle, motor end plate or nerve fiber.
Pharmacokinetics
The pharmacokinetics of metaxalone was studied in healthy adult volunteers after a single administration of metaxalone in a sober and well-fed environment at doses ranging from 400 to 800 mg.
Absorption
Peak plasma metaxalone concentrations occur approximately 3 hours after a 400 mg oral dose under sober conditions. The logarithmic concentrations of metaxalone then decrease with a terminal half-life of 9.0 ± 4.8 hours. Doubling the dose of Metaxalone from 400 mg to 800 mg results in an approximately proportional increase in metaxalone exposure, as evidenced by peak plasma concentrations (Cmax) and area under the curve (AUC). Dose proportionality at doses above 800 mg has not been studied.The absolute bioavailability of metaxalone is not known.
The pharmacokinetic parameters of metaxalone with a single dose in two groups of healthy volunteers are shown in Table 1.
Table 1: Average (% CV) pharmacokinetic parameters Metaxalone
Dose (mg) C ml ng / ) Tmax (h) AUC∞ (ng & ml; h / ml) t½ (h) CL / F (L / h) 400 1 983 (53) 3.3 (35) 7479 (51) 9.0 (53) 68 (50) 800 2 1816 (43) 3.0 (39) 15044 (46) 8.0 (58) 66 (51) 1 Subjects received 1×400 mg tablet sober (N = 42)
2 Subjects received 2×400 mg tablets sober (N = 59)Food Effects
A randomized, bidirectional, crossover study was conducted in 42 healthy volunteers (31 males, 11 females) who received a 400 mg metaxalone tablet sober and after a standard high-fat breakfast.Subjects ranged from 18 to 48 years old (mean age = 23.5 ± 5.7 years). Compared to sober states, the presence of food with a high fat content increased by 177.5% during administration of drug C and increased AUC (AUC0-t, AUC∞) by 123.5% and 115.4%, respectively. Time to peak concentration (Tmax) was also delayed (4.3 hours versus 3.3 hours), and the terminal half-life was reduced (2.4 hours versus 9.0 hours) under feeding versus fasting.
In a second study with a similar effect, healthy volunteers (N = 59, 37 men, 22 women) were given two tablets of metaxalone 400 mg (800 mg) at the age of 18-50 years (mean age = 25).6 ± 8.7 years). Compared with sober states, the presence of food with a high fat content increased by 193.6% during administration of drug C and increased AUC (AUC0-t, AUC, ∞) by 146.4% and 142.2%, respectively. Time to peak the concentration (Tmax) was also delayed (4.9 hours versus 3.0 hours) and the terminal half-life was shortened (4.2 hours versus 8.0 hours) under feeding versus fasting conditions. Similar nutritional effects were observed in the aforementioned study when a Metaxalone tablet was administered instead of two 400 mg Metaxalone tablets.An increase in metaxalone exposure, which coincides with a decrease in half-life, may be due to more complete absorption of metaxalone in the presence of a high-fat diet (Figure 1).
Figure 1: Mean (SD) concentrations of metaxalone after 800 mg dose under fasting and feeding conditions
Distribution, metabolism and excretion
Although plasma protein binding and absolute bioavailability of metaxalone are unknown, the apparent volume of distribution (V / F ~ 800 L) and lipophilia (log P = 2.42) of metaxalone indicate that the drug is mainly distributed in tissues.Metaxalone is metabolized in the liver and excreted in the urine as unidentified metabolites. Hepatic cytochrome P450 enzymes play a role in the metabolism of metaxalone. In particular, CYP1A2, CYP2D6, CYP2E1 and CYP3A4 and to a lesser extent CYP2C8, CYP2C9 and CYP2C19 metabolize metaxalone.
Metaxalones do not significantly inhibit major CYP enzymes such as CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4. Metaxalone does not induce significant induction of important CYP enzymes such as CYP1A2, CYP2B6 and CYP3A4 in vitro .
Pharmacokinetics in special population groups
Age
The effect of age on the pharmacokinetics of metaxalone was determined after one administration of two tablets of 400 mg (800 mg) under fasting and feeding conditions. The results were evaluated separately and also in combination with the results of three other studies. Using the combined data, the results show that the pharmacokinetics of metaxalone under sober conditions is significantly more dependent on age than under feeding, with bioavailability increasing with age under sober conditions.
Bioavailability of metaxalone under fasting and feeding conditions in three groups of healthy volunteers of different ages is shown in Table 2.
Table 2: Average pharmacokinetic parameters (% CV) After a single administration of two tablets of metaxalone 400 mg (800 mg) under fasting conditions and feeding
Age (years) Junior volunteers Elderly volunteers 25.6 ± 8.7 39.3 ± 10.8 71.5 ± 5.0 N 59 21 23 Food Tasty Fed Tasty Fed Tasty ml 1816 (43) 3510 (41) 2719 (46) 2915 (55) 3168 (43) 36 80 (59) TMAX (h) 3.0 (39) 4.9 (48) 3.0 (40) 8.7 (91) 2.6 ( 30) 6.5 (67) AUC0-t (ng • h / ml) 14531 (47) 20683 (41) 19836 (40) 20482 (37) 23797 (45) 24340 (48) AUC∞ (ng • h / ml) 15045 (46) 20833 (41) 20490 (39) 20815 (37) 24194 (44) 24704 (47) Sex
The effect of gender on the pharmacokinetics of metaxalone was evaluated in an open-label study in which 48 healthy adults (24 men, 24 women) were administered two 400 mg metaxalone tablets (800 mg) under sober conditions.