About all

Medicines buspirone: Drug Database | Medication Decision Support

BuSpar Oral: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing

Uses

This medication is used to treat anxiety. It may help you think more clearly, relax, worry less, and take part in everyday life. It may also help you to feel less jittery and irritable, and may control symptoms such as trouble sleeping, sweating, and pounding heartbeat. Buspirone is a medication for anxiety (anxiolytic) that works by affecting certain natural substances in the brain (neurotransmitters).

How to use Buspar Tablet

Take this medication by mouth as directed by your doctor, usually 2 or 3 times a day. You may take this medication with or without food, but it is important to choose one way and always take it the same way so that the amount of drug absorbed will always be the same.

Buspirone may come in a tablet that can be split to get the correct dose for you. Follow the manufacturer’s Patient Instruction Sheet or ask your pharmacist how to split the tablet to get your dose.

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.

Dosage is based on your medical condition and response to therapy. Use this medication regularly in order to get the most benefit from it. To help you remember, use it at the same times each day. When this medication is started, symptoms of anxiety (such as restlessness) may sometimes get worse before they improve. It may take up to a month or more to get the full effect of this medication.

Inform your doctor if your symptoms last or get worse.

Side Effects

Dizziness, drowsiness, headache, nausea, nervousness, lightheadedness, restlessness, blurred vision, tiredness, and trouble sleeping may occur. If any of these effects last or get worse, notify your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Rarely, patients taking buspirone may develop movement disorders such as shakiness (tremors), muscle stiffness, mask-like facial expression, jerky walking movements, or a condition known as tardive dyskinesia. In some cases, these conditions may be permanent. Tell your doctor right away if you develop any unusual/uncontrolled movements (especially of the face, mouth, tongue, arms, or legs).

Get medical help right away if you have any very serious side effects, including: easy bleeding/bruising, shortness of breath, chest pain, fast/irregular heartbeat.

A very serious allergic reaction to this drug is rare. However, get medical help right away 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 list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist .

In the US – Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Precautions

Before taking buspirone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can 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 of: kidney problems, liver problems, bipolar disorder (manic-depression), Parkinson’s disease.

This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

If you are taking other medications for anxiety, do not suddenly stop them unless directed by your doctor. Buspirone will not prevent withdrawal symptoms from other medications, and your dose may need to be lowered slowly when you switch to buspirone. Discuss your treatment plan with your doctor. If you experience withdrawal symptoms, tell your doctor right away.

During pregnancy, this medication should only be used when clearly needed. Tell your doctor if you are pregnant before using this medication. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. However, similar drugs pass into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.

Interactions

See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.

Some products that may interact with this drug are: antidepressants (including SSRIs such as fluoxetine, tricyclic antidepressants such as amitriptyline/nortriptyline, trazodone), haloperidol.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before and after treatment with this medication. Ask your doctor when to start or stop taking this medication.

Other medications can affect the removal of buspirone from your body, which may affect how buspirone works. Examples include azole antifungals (such as itraconazole), corticosteroids (such as dexamethasone), diltiazem, nefazodone, rifamycins (such as rifabutin), ritonavir, drugs used to treat seizures (such as phenytoin, phenobarbital), among others.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

This medication may interfere with certain medical/laboratory tests (including brain scan for Parkinson’s disease), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

Does Buspar Tablet interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

Do not share this medication with others.

Keep all medical and lab appointments.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, except as may be authorized by the applicable terms of use.

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

Buspirone (Buspar) – Side Effects, Interactions, Uses, Dosage, Warnings

uses

What is Buspirone (Buspar) used for?

  • Anxiety

warnings

What is the most important information I should know about Buspirone (Buspar)?

You should not use buspirone if you are allergic to it.

Do not use buspirone if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

You may need to wait 14 days after stopping buspirone before you can take an MAOI.

Tell your doctor if you have ever had:

  • kidney disease; or
  • liver disease.

Be sure your doctor knows if you also take stimulant medicine, opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson’s disease, migraine headaches, serious infections, or prevention of nausea and vomiting. These medicines may interact with buspirone and cause a serious condition called serotonin syndrome.

Tell your doctor if you are pregnant.

You should not breastfeed while using buspirone.

Do not give this medicine to a child without medical advice.

User Reviews & Rating

Overall rating for Buspirone (Buspar)

3. 4

out of  5

Side Effects

Easy to Use

Effectiveness

Read Buspirone (Buspar) Reviews

Side Effects

What are the side effects of Buspirone (Buspar)?

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • chest pain;
  • shortness of breath; or
  • a light-headed feeling, like you might pass out.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Common side effects may include:

  • headache;
  • dizziness, feeling light-headed;
  • nausea; or
  • feeling nervous or excited.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Pregnancy & Breastfeeding

Can I take Buspirone (Buspar) if I’m pregnant or breastfeeding?

B

No evidence of risk in humans

Based on FDA pregnancy categories

Tell your doctor if you are pregnant.

You should not breastfeed while using buspirone.

Interactions

What drugs and food should I avoid while taking Buspirone (Buspar)?

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

Drinking alcohol may increase certain side effects of buspirone.

Grapefruit may interact with buspirone and lead to unwanted side effects. Avoid the use of grapefruit products.

Dosage Guidelines & Tips

How to take Buspirone (Buspar)?

Use Buspirone (Buspar) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

What should I do if I missed a dose of Buspirone (Buspar)?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Overdose Signs

What happens if I overdose on Buspirone (Buspar)?

If you think you or someone else may have overdosed on: Buspirone (Buspar),  call your doctor or the Poison Control center

(800) 222-1222

If someone collapses or isn’t breathing after taking Buspirone (Buspar), call 911

911

What to Expect

It could take three to four weeks of taking buspirone before you start to feel better.

Secondary Uses

Sometimes, doctors recommend using buspirone “off-label” to help the following conditions:

  • Depression
  • Adverse sexual effects
  • Certain substance use disorders
  • Post-traumatic stress disorder (PTSD)
  • Irritability, agitation, or aggression in children or in people with dementia
  • Tardive dyskinesia
  • Other psychiatric or neurological conditions

Images

TV 53

Color: white

Shape: round

Imprint: TV 53

TEVA, 54

Color: white

Shape: round

Imprint: TEVA, 54

TV 1003, 5 5 5

Color: white

Shape: rectangular

Imprint: TV 1003, 5 5 5

Description of BUSPIRONE indications, dosages, contraindications of the active substance BUSPIRONE

Rec. INN
WHO registered


drug interaction

Included in preparations:
list

Pharmacological action

Anxiolytic agent, azaspirodecanedione derivative. The mechanism of action has not been definitively established. According to pharmacological properties, it does not apply to benzodiazepines or barbiturates. It has a selective anxiolytic effect. It does not have anticonvulsant activity, does not have a muscle relaxant effect. It does not have a pronounced sedative effect, especially at low doses.

High affinity for serotonin 5-HT 1A receptors in dorsal raphe neurons and moderate affinity for dopamine D 2 receptors in the brain. Buspirone does not have a pronounced affinity for benzodiazepine receptors, it does not affect the binding of GABA.

Unlike benzodiazepines, the level of spontaneous excitation of noradrenergic cells in the bluish locus (locus ceruleus) increases rather than decreases under the action of buspirone. These specific differences in the site of action are responsible for differences in the development of dependence and tolerance between benzodiazepines and buspirone.

Buspirone is not believed to cause tolerance, physical or psychological dependence.

Pharmacokinetics

After oral administration, it is rapidly absorbed from the gastrointestinal tract, Cmax max in blood plasma is reached after 40-90 minutes. Bioavailability is low due to the pronounced effect during the “first pass” through the liver. When taken with food, it is possible to increase bioavailability due to impaired absorption of buspirone from the gastrointestinal tract and, therefore, a decrease in presystemic clearance. Plasma protein binding of buspirone is about 95%. It undergoes intensive metabolism in the liver with the participation of the CYP3A4 isoenzyme. As a result of hydroxylation, several inactive metabolites are formed, oxidative dealkylation leads to the formation of 1-(2-pyrimidinyl)-piperazine, which has anxiolytic activity. T 1/2 buspirone is usually 2-4 hours, but the final T 1/2 can be 11 hours. It is excreted mainly as metabolites in the urine and also in the feces.

Indications of the active substance
BUSPIRON

Treatment of anxiety disorders or temporary relief of symptoms of anxiety.

Open list of ICD-10 codes

F40 Phobic anxiety disorders (including agoraphobia, social phobias)
F41.2 Mixed anxiety and depressive disorder
R45.2 Alarm condition due to failures and misfortunes

Dosage regimen

Inside adults at the beginning of treatment – 5 mg 3 times / day. If necessary, the dose is increased by 5 mg / day every 2-3 days until the desired effect is achieved. The maximum dose is 45-60 mg / day.

Side effects

Possible: dizziness, headache, restlessness syndrome.

Rare: blurred vision, decreased ability to concentrate, dry mouth, myalgia, muscle spasms, muscle cramps and rigidity, tinnitus, sleep disturbance, nightmares, general weakness, dyspepsia, chest pain, depression , tachycardia, paresthesia, sore throat, fever.

Contraindications for use

Severe renal impairment, severe hepatic impairment, hypersensitivity to buspirone.

Pregnancy and lactation

Buspirone should be avoided during pregnancy and lactation.

Use in hepatic impairment

Contraindicated in severe hepatic impairment.

Use in impaired renal function

Contraindicated in severe renal impairment.

Use in children

The safety and efficacy of buspirone in children and adolescents under 18 years of age have not been established.

Precautions

Buspirone is not used to treat anxiety and reduce tension associated with the stresses of everyday life.

Should not be used in patients with epilepsy or with a history of a tendency to develop seizures.

Use with caution in patients with hepatic and/or renal impairment.

Patients with drug abuse or a history of drug dependence should be closely monitored during treatment to detect the development of buspirone tolerance or dependence.

Controlled studies have shown that buspirone is not effective for long-term (more than 3-4 weeks) treatment of anxiety. However, when used for several months, no side effects were detected. If buspirone is used for a long time, then its effectiveness should be checked at regular intervals.

During the period of treatment, the patient should refrain from activities associated with the need for concentration and high speed of psychomotor reactions.

The safety and efficacy of buspirone in children and adolescents under 18 years of age have not been established.

Drug interactions

Buspirone is metabolized in the liver with the participation of the CYP3A4 isoenzyme and, apparently, can interact with drugs that are inhibitors or inducers of this isoenzyme.

The use of buspirone in clinical practice

Buspirone (spitomin) is a non-benzodiazepine anxiolytic, which is a derivative of azapirone. Azapirones are a class of drugs with high affinity for serotonin 5-HT1A receptors located on the body and in the endings of serotonergic neurons, as well as in the dendrites of postsynaptic neurons with which serotonergic endings contact. The anti-anxiety effect of buspirone is not associated with an effect on GABA-benzodiazepine receptors. However, in terms of anxiolytic activity, buspirone is comparable to such benzodiazepines as diazepam, lorazepam or alprazolam, but unlike them, it does not cause drug dependence, cognitive and psychomotor impairment, pronounced sedative and muscle relaxant effects [1].

Mechanism of action of buspirone

The mechanism of the anxilytic action of buspirone, which predetermines its features, is mainly due to the effect on serotonin receptors. Buspirone has a high affinity for presynaptic serotonin (5-HT1A) receptors, of which it is an agonist, as well as for postsynaptic serotonin receptors, for which it can be considered as a partial (partial) agonist [1].

Partial agonists are ligands that bind to receptors but are only able to cause their partial activation. If a partial agonist interacts with free receptors, it causes incomplete (50%) cell activation. If a partial agonist acts on a tissue whose receptors are already activated by a full agonist, then due to the displacement of the latter from their connection with the receptor, the cell response decreases and, therefore, it has a blocking effect.

Thus, due to its receptor action, buspirone reduces the synthesis and release of serotonin, reduces the activity of serotonergic neurons in the raphe nuclei (“serotonin stabilizer”). Buspirone is also able to interact with postsynaptic 5-HT2 receptors, but has a low affinity for them. Being a partial agonist, due to its postsynaptic action, it can theoretically reduce serotonergic activity and cause an anxiolytic effect, and due to its action on somatodendritic serotonin presynaptic autoreceptors, it can theoretically increase serotonergic activity and cause an antidepressant effect.

To a lesser extent, the drug selectively blocks pre- and postsynaptic D2-dopamine receptors. Moreover, it was originally developed as an antipsychotic, but later it turned out that it has a low affinity for dopamine receptors, and its presynaptic action prevails over the postsynaptic one, which prevents the neuroleptic effect.

Experimental studies have indicated a decrease in serotonin turnover with low doses of buspirone, reflecting stimulation of presynaptic autoreceptors. However, repeated administration of buspirone reduces the response of somatodendritic 5-HT1A receptors, since the decrease in 5-HT metabolism was less pronounced.

Buspirone can act as a partial agonist at postsynaptic serotonin 5-HT1A receptors in the hippocampus and prefrontal cortex, as well as presynaptic autoreceptors on the bodies of serotonergic neurons. Since the effect of azapirones develops over several days, it does not appear to be related to their direct action on receptors. Animal studies suggest that the anxiolytic effect of these drugs is due to their action on presynaptic receptors, and the antidepressant effect is due to the action on postsynaptic receptors.

Decreased serotonin circulation also occurs in the striatum, which may be accompanied by an inhibitory effect on dopaminergic transmission. This effect is manifested in the fact that the co-administration of buspirone can attenuate apomorphine sensitization. Thus, buspirone at a relatively low dose can counteract the side effect of apomorphine. However, the introduction of buspirone at a higher dose caused sensitization of motor behavior [2].

This effect may be due to blockade of presynaptic dopamine autoreceptors. The introduction of a relatively high dose of buspirone in the experiment caused a sharp increase in the synthesis and metabolism of dopamine in the striatum.

The experiment has shown that the administration of buspirone in the brain dialysate reduces the level of serotonin by 50%, but increases the level of dopamine by 100% and norepinephrine by 140%, which indicates a complex effect of buspirone on monoaminergic neurotransmission [3].

However, in addition to the action on autoreceptors, buspirone also has another point of application, since the administration of haloperidol, which blocks D1- and D2-postsynaptic mesolimbic and striatal receptors, did not block the dopaminomimetic effect of buspirone. It has been shown that the antagonistic effect of the drug on D2 receptors is 15 times weaker than the effect on 5-HT1A receptors. Buspirone is a relatively weak blocker of postsynaptic dopamine receptors, even at high doses. It binds with higher affinity to D3 and D4 receptors than to D2 receptors. The action on presynaptic dopamine receptors is stronger than the blockade of postsynaptic receptors. Only in super-high doses, postsynaptic striatal D1- and D2-receptors are blocked quite actively. However, weak postsynaptic dopaminergic antagonism weakens the presynaptic dopaminomimetic effect of the drug, avoiding stereotypy [2, 3].

Use of buspirone in generalized anxiety and other affective disorders

The greatest experience with the use of buspirone has been accumulated in generalized anxiety disorder (GAD). Clinical studies of the last 30 years have been accompanied by continuous improvement in the nosological structure of anxiety disorders. At the beginning of the 20th century, the understanding of anxiety disorders was rather vague, but over time their place among other mental disorders has been more clearly defined, partly under the influence of pharmacological research.

Symptoms of GAD are chronic and often observed in patients who visit general practitioners. Typically, such patients present vague somatic complaints of fatigue, muscle pain or tension, and sleep disturbances.

Buspirone is the first FDA-approved non-benzodiazepine anxiolytic for the treatment of GAD, based on studies showing that it is comparable in efficacy to benzodiazepines.

In accordance with DSM-V [4] criteria, GAD is characterized by:

A. Excessive anxiety and worry (anxious expectations) that occurs most of the days for at least 6 months and manifests itself in a variety of events or activities (for example, in the performance of professional duties or while studying at school).

B. Difficulty in controlling anxiety.

C. Presence most of the days for 6 months at least 3 of the following symptoms: restlessness or restlessness; fast fatiguability; difficulty concentrating and being distracted; irritability; muscle tension; sleep disturbance.

D. Clinically significant distress or impairment of social, occupational, or other activities caused by anxiety, restlessness, or physical (psychomotor) symptoms.

E. These disorders that cannot be explained by a physiological effect of a psychoactive substance or medical illness.

E. These disorders that cannot be explained by another mental illness.

Buspirone has also been successfully used for the prophylactic treatment of migraine and alcoholism in individuals with comorbid anxiety disorder, as well as for the treatment of anxious depression, anxiety and agitation in patients with traumatic brain injury [5, 6].

The direct antidepressant effect of buspirone, independent of its anxiolytic action, has also been demonstrated. It may be due to the fact that the sensitivity of 5-HT1A autoreceptors in depression is increased, while the properties of postsynaptic 5-HT1A and 5-HT2A receptors do not change in untreated patients with depression.

Data on the effectiveness of buspirone in obsessive-compulsive disorder are contradictory, but some studies show a positive effect of the drug, especially when combined with other psychopharmacological drugs, primarily antidepressants. An open study showed that the addition of buspirone (at a dose of 30-90 mg/day) to selective serotonin reuptake inhibitors (SSRIs) increases the effectiveness of the treatment of body dysmorphic disorder in almost half of patients, mainly in those who had a partial effect on serotonergic antidepressants [7, 8].

Buspirone can be considered as an alternative to antidepressants in the treatment of social phobia. The effect of buspirone on social phobia has been shown in a placebo-controlled study. When added to SSRIs, buspirone may correct some of their side effects. For example, it has been shown that at a dose of 15-60 mg/day it can reduce sexual dysfunction and bruxism [8].

Antiaggressive effect of buspirone

Separate mention should be made of the anti-aggressive effect of buspirone in agitation and aggressive actions in patients with dementia, attention deficit with hyperactivity, and traumatic brain injury [8]. At the same time, the effect of buspirone at a dose of 15–60 mg/day was noted both in relation to verbal (60%) and physical (90%) aggression [9–12].

Effect of buspirone on cognitive functions

Data on the effect of buspirone on cognitive functions are contradictory, some studies show a moderate positive effect on regulatory functions, in others there was no clear effect [13]. In any case, unlike benzodiazepines and sedatives, buspirone does not have a negative effect on cognitive functions, which distinguishes it from other drugs used to correct anxiety disorders [14].

Use of buspirone for the treatment of dependence syndrome

Due to its dopaminergic action, buspirone can be used to treat dependence syndrome. Initially, this quality was found in relation to addiction to cocaine. It has been experimentally shown that intramuscular administration of buspirone blocks D2 and D3 receptors, while oral administration of buspirone blocks D3 receptors more selectively, occupying more than 80% of the receptors. Thus, for the treatment of addiction, higher doses may be required – 2-3 times higher than for the treatment of anxiety (up to a maximum of 60 mg). As shown by previous studies, these doses are safe and well tolerated [15]. Correction of withdrawal anxiety under the influence of buspirone may also contribute to the treatment of alcohol and tobacco dependence [16-18].

Use of buspirone in extrapyramidal disorders

Experimental and clinical studies indicate that buspirone may be effective in the treatment of tardive dyskinesia. Tardive dyskinesia is characterized by involuntary movements involving the muscles of the head, limbs, or trunk. It usually occurs against the background of long-term therapy with antipsychotics, often manifesting itself or intensifying after their cancellation. Tardive dyskinesia is usually resistant to various treatments. Although the evidence base for buspirone in tardive dyskinesia is low, it may be an alternative to others (particularly dopaminergic drugs) with dangerous side effects. The mechanism of action of buspirone in tardive dyskinesia is unclear [19, 20].

Buspirone may also be effective in patients with Parkinson’s disease suffering from dyskinesias on the background of long-term levodopa therapy. The mechanism of action of the drug is not clear enough in this case either, but the therapeutic effect depends on the dose. In recent years, using pathomorphological and imaging methods, it has been shown that the serotonergic system is involved in the pathological process in Parkinson’s disease, in particular, in the pathogenesis of a number of non-motor symptoms, as well as medicinal dyskinesias. Because of this, drugs that act on the serotonergic system can be effective against dyskinesias and non-motor symptoms such as depression, chronic fatigue, and psychotic disorders [21].

It has already been mentioned that 5-HT1A receptor agonists regulate the striatal concentration of dopamine formed from exogenous levodopa, whereby buspirone can reduce drug-induced dyskinesias (“peak dose”) in Parkinson’s disease.

In a clinical study [22], it was shown that consecutive administration of the drug for 3 days (at a dose of 15-30 mg / day), but not a single dose of the drug at a dose of 10 and 20 mg, led to a 20% reduction in dyskinesias (without an increase in symptoms parkinsonism). In another study, a 3-week dose of buspirone at a dose of 20 mg/day reduced the severity of drug-induced dyskinesias by 71% without any negative effect on the symptoms of parkinsonism. Thus, buspirone can be considered as a potentially effective strategy in the correction of drug-induced dyskinesias.

These clinical data are experimentally confirmed – at a dose of 2 mg / kg, buspirone attenuated violent movements by 45% in mice with an experimental model of dopaminergic dyskinesias. Administration of buspirone to rats at a dose of 0.25-2.5 mg/kg 30 min before levodopa reduced dyskinesias and improved locomotor activity. In the experiment, buspirone reduced catalepsy in rats induced by 6-OHDA and haloperidol.

The effectiveness of buspirone was also shown in dyskinesias that occurred after transplantation of fetal midbrain tissue. It is believed that transplantation dyskinesias are associated with serotonergic neurotransmission [23]. Correction of dyskinesias is more effective with a high dose of 5-HT1A agonist, which more completely blocks mediator release. Dopaminergic reinnervation after transplantation causes persistent dyskinesias due to the uncontrolled release of dopamine induced by serotonin. The release of dopamine occurs in this case with a lower intensity than with “peak dose” dyskinesia. Accordingly, the effect in this situation is more pronounced with systemic administration of lower doses of 5-HT1A agonists [22, 23].

Buspirone can be effective in hereditary spinocerebellar ataxias, which is explained by the pronounced serotonergic innervation of the cerebellum [24]. It is suggested that this effect may also be associated with an effect on the noradrenergic pathways. This assumption has been confirmed in several studies showing that buspirone reduces mild to moderate cerebellar ataxia by 37%. The positive effect of buspirone on the severity of ataxia was confirmed in a small placebo-controlled study [25, 26].

Practical aspects of the use of buspirone (Spitomin)

The main indications for the use of buspirone (spitomin) registered in the Russian Federation are generalized anxiety disorder (GAD), panic disorder, autonomic dysfunction syndrome, alcohol withdrawal syndrome (as adjuvant therapy), depressive disorders (as adjuvant therapy, but not prescribed for monotherapy depression). The literature describes the use of buspirone for various anxiety conditions, tobacco withdrawal, depression, as well as autism, obsessive-compulsive and premenstrual syndromes (in which the drug acts as an adjuvant). The mechanism of action makes it possible to use it for the treatment of resistant depression (in combination with an antidepressant) [27].

The therapeutic (anxiolytic) effect develops gradually, manifests itself after 7-14 days and reaches a maximum after 4 weeks.

The goal of treatment for affective disorders may be to achieve complete remission or at least symptomatic relief and, if possible, to prevent possible relapses. In chronic anxiety disorders, long-term maintenance therapy with buspirone may be required for long-term symptom control.

An important advantage of buspirone is that, unlike classical anxiolytics such as benzodiazepines, it does not adversely affect psychomotor functions, does not cause tolerance, drug dependence and withdrawal symptoms, and does not potentiate the effect of alcohol. However, during the period of treatment with buspirone, alcohol should be excluded [28].

The absence of a therapeutic effect within 6-8 weeks requires an increase in the dose, but in some cases indicates resistance to the drug. In the absence of an effect, the drug is usually replaced with another agent (benzodiazepine or antidepressant). With a partial effect, an antidepressant, sedative or hypnotic (with insomnia) can be added to enhance its action. Especially often, buspirone is used in combination with an SSRI or a selective serotonin and norepinephrine reuptake inhibitor (SNRI) [29].

Use in persons under 18 years of age is contraindicated, according to the current instructions in the Russian Federation for buspirone. In children and adolescents from 6 to 18 years of age, there have been no efficacy studies for anxiety disorder. Pregnancy and breastfeeding are also contraindications, although there is no direct evidence of danger.

Buspirone is generally well tolerated. Side effects, if they are observed, usually occur at the beginning of the course of treatment and then disappear, despite the continuation of the drug. In some cases, a dose reduction is necessary. As a side effect, the drug can cause dizziness, headache, weakness, sleep disturbance, decreased attention, extrapyramidal disorders (very rarely), confusion, nausea, dry mouth, diarrhea, vomiting, constipation, weight loss, weight gain, myalgia, muscle spasms, rash, sweating, paresthesia. In case of an overdose, vomiting, dizziness, miosis, depression of consciousness are possible. The drug is carefully combined with antipsychotics, cardiac glycosides, antihypertensive and antidiabetic agents, oral contraceptives. Interaction with MAO inhibitors can lead to serotonin syndrome or hypertensive crisis with more limited symptoms, therefore, the simultaneous use of buspirone and MAO inhibitors is contraindicated by the instructions for medical use.

In the Russian Federation, the drug is presented in the form of 10 mg divided tablets. The initial dose is 5 mg / day, if necessary, it is increased by 5 mg every 5 days. The average daily dose is 15 mg. The maximum single dose is 30 mg, the maximum daily dose is 60 mg. The daily dose is usually divided into 2-3 doses. The advantages of the drug include safety, lack of dependence and withdrawal syndrome, sexual dysfunction and weight gain. Moreover, buspirone is able to reduce sexual dysfunction caused by generalized anxiety and serotonergic antidepressants [28, 30].

The peculiarities of the drug include the gradual onset of the full clinical effect (within 4 weeks), while benzodiazepines act more quickly.

Buspirone is metabolized primarily by the microsomal enzyme CYP450 3A4. T½ is approximately 2-3 hours. Particular care should be taken when combined with CYP450 3A4 inhibitors (for example, diltiazem, verapamil, itraconazole, erythromycin), which can reduce the clearance of buspirone and increase its level in the blood. You should also avoid drinking large amounts of grapefruit and grapefruit juice at the same time. The dose of buspirone should also be reduced when using HIV protease inhibitors or ketoconazole. Conversely, CYP450 3A4 inducers (eg carbamazepine and rifampicin) may increase the clearance of buspirone. Buspirone increases blood levels of nordiazepam, the active metabolite of diazepam, which can cause dizziness, headache, and nausea.

In mild to moderate renal and hepatic insufficiency, liver cirrhosis, heart failure, in the elderly, the drug is prescribed in smaller doses. When discontinuing the drug, a gradual dose reduction is usually not necessary. In severe renal, hepatic insufficiency, uncontrolled epilepsy, glaucoma, myasthenia gravis, the drug is contraindicated.

Thus, buspirone, with its unique neurotransmitter effects, significantly expands the treatment options for a wide range of mental and neurological disorders – from anxiety disorders to dyskinesia in Parkinson’s disease and ataxia. The relative safety of the drug makes its use in clinical practice very promising.