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

Warnings:

Antidepressant medications are used to treat a variety of conditions, including depression and other mental/mood disorders. These medications can help prevent suicidal thoughts/attempts and provide other important benefits. However, a small number of people (especially people younger than 25) who take antidepressants for any condition may experience worsening depression, other mental/mood symptoms, or suicidal thoughts/attempts. It is very important to talk with the doctor about the risks and benefits of antidepressant medication (especially for people younger than 25), even if treatment is not for a mental/mood condition.

Tell the doctor right away if you notice worsening depression/other psychiatric conditions, unusual behavior changes (including possible suicidal thoughts/attempts), or other mental/mood changes (including new/worsening anxiety, panic attacks, trouble sleeping, irritability, hostile/angry feelings, impulsive actions, severe restlessness, very rapid speech). Be especially watchful for these symptoms when a new antidepressant is started or when the dose is changed.

Warnings:

Antidepressant medications are used to treat a variety of conditions, including depression and other mental/mood disorders. These medications can help prevent suicidal thoughts/attempts and provide other important benefits. However, a small number of people (especially people younger than 25) who take antidepressants for any condition may experience worsening depression, other mental/mood symptoms, or suicidal thoughts/attempts. It is very important to talk with the doctor about the risks and benefits of antidepressant medication (especially for people younger than 25), even if treatment is not for a mental/mood condition.

Tell the doctor right away if you notice worsening depression/other psychiatric conditions, unusual behavior changes (including possible suicidal thoughts/attempts), or other mental/mood changes (including new/worsening anxiety, panic attacks, trouble sleeping, irritability, hostile/angry feelings, impulsive actions, severe restlessness, very rapid speech). Be especially watchful for these symptoms when a new antidepressant is started or when the dose is changed.

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Uses

Venlafaxine is used to treat depression, anxiety, panic attacks, and social anxiety disorder (social phobia). It may improve your mood and energy level and may help restore your interest in daily living. It may also decrease fear, anxiety, unwanted thoughts, and the number of panic attacks. Venlafaxine is known as a serotonin-norepinephrine reuptake inhibitor (SNRI). It works by helping to restore the balance of certain natural substances (serotonin and norepinephrine) in the brain.

How to use venlafaxine oral

Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start using venlafaxine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth as directed by your doctor, usually once daily with food, either in the morning or evening.

Do not crush, chew, or dissolve this medication. Doing so can release all of the drug at once, increasing the risk of side effects. Swallow whole without crushing or chewing.

If you are taking the capsules, swallow them whole. If you have trouble swallowing the capsules whole, you may open the capsule and sprinkle the contents onto a spoonful of applesauce. Swallow all of the mixture right away without chewing. Drink a glass of water after each dose.

The dosage is based on your medical condition and response to treatment. To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor’s instructions carefully. Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

Keep taking this medication even if you feel well. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when this drug is suddenly stopped. Also, you may experience symptoms such as confusion, mood swings, blurred vision, headache, tiredness, sleep changes, and brief feelings similar to electric shock. Your dose may need to be gradually decreased to reduce side effects. Report any new or worsening symptoms right away.

It may take several weeks to feel the benefit of this medication. Tell your doctor if your condition lasts or gets worse.

Side Effects

See also Warning section.

Nausea, drowsiness, dizziness, dry mouth, constipation, loss of appetite, blurred vision, nervousness, trouble sleeping, unusual sweating, or yawning may occur. If any of these effects last or get worse, tell your doctor 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.

This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.

Tell your doctor right away if you have any serious side effects, including: easy bleeding/bruising, decreased interest in sex, changes in sexual ability, muscle cramps/weakness, shaking (tremor).

Get medical help right away if you have any very serious side effects, including: cough that doesn’t go away, shortness of breath, chest pain, severe/pounding headache, black stools, vomit that looks like coffee grounds, eye pain/swelling/redness, widened pupils, vision changes (such as seeing rainbows around lights at night), seizure.

This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.

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 venlafaxine, tell your doctor or pharmacist if you are allergic to it; or to desvenlafaxine; 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: bleeding problems, personal or family history of glaucoma (angle-closure type), high blood pressure, heart problems (such as heart failure, previous heart attack), high cholesterol, kidney disease, liver disease, seizure disorder, thyroid disease.

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

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this drug, especially dizziness when standing. Older adults may also be more likely to develop a type of salt imbalance (hyponatremia), especially if they are taking “water pills” (diuretics). Dizziness and salt imbalance can increase the risk of falling. Older adults may also be at greater risk for bleeding while using this drug.

Children may be more sensitive to the side effects of the drug, especially loss of appetite and weight loss. Monitor weight and height in children who are taking this drug.

During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. Also, babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely develop withdrawal symptoms such as feeding/breathing difficulties, seizures, muscle stiffness, or constant crying. If you notice any of these symptoms in your newborn, tell the doctor promptly.

Since untreated mental/mood problems (such as depression, anxiety, panic attacks) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss the benefits and risks of using this medication during pregnancy with your doctor.

This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

Interactions

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: other drugs that can cause bleeding/bruising (including antiplatelet drugs such as clopidogrel, NSAIDs such as ibuprofen/naproxen, “blood thinners” such as dabigatran/warfarin).

Aspirin can increase the risk of bleeding when used with this medication. However, if your doctor has directed you to take low-dose aspirin for heart attack or stroke prevention (usually 81-162 milligrams a day), you should continue taking it unless your doctor instructs you otherwise. Ask your doctor or pharmacist for more details.

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 at least 7 days after treatment with this medication. Ask your doctor when to start or stop taking this medication.

The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/”ecstasy,” St. John’s wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, other SNRIs such as duloxetine/milnacipran), tryptophan, among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

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.

Venlafaxine is very similar to desvenlafaxine. Do not take medications containing desvenlafaxine while using venlafaxine.

This medication may interfere with certain lab tests (including urine tests for amphetamines), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

Does venlafaxine oral 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. Symptoms of overdose may include: severe drowsiness, seizures, fast/irregular heartbeat.

Do not share this medication with others.

Lab and/or medical tests (such as blood pressure, cholesterol) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

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.

Images

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Color: whiteShape: roundImprint: OS 304

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Color: whiteShape: roundImprint: OS 303

This medicine is a dark orange, oblong, capsule imprinted with “E” and “89”.

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Color: whiteShape: roundImprint: OS 301

This medicine is a dark orange, oblong, capsule imprinted with “E” and “89”.

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Color: whiteShape: roundImprint: 13 50

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Color: whiteShape: roundImprint: 13 48

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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.

Venlafaxine – StatPearls – NCBI Bookshelf

Continuing Education Activity

Venlafaxine is FDA approved to treat and manage symptoms of depression, social anxiety disorder, and cataplexy. Off-label, venlafaxine can be used for attention deficit disorder, fibromyalgia, diabetic neuropathy, complex pain syndromes, hot flashes, migraine prevention, post-traumatic stress disorder, obsessive-compulsive disorder, and premenstrual dysphoric disorder. Venlafaxine may be used independently or as part of combination therapy with other drugs. This activity outlines the indications, mechanism of action, administration methods, significant adverse effects, contraindications, toxicity, and monitoring, of venlafaxine so providers can direct patient therapy where it is indicated as part of the interprofessional team.

Objectives:

• Identify the approved and off-label indications for venlafaxine.

• Describe the adverse effects associated with venlafaxine, including the FDA black-box warning.

• Summarize the relevant drug-drug interactions of venlafaxine.

• Explain the importance of collaboration and coordination among the interprofessional team and how it can enhance patient care with venlafaxine therapy to improve patient outcomes for patients who have depression and related conditions for which it is indicated.

Access free multiple choice questions on this topic.

Indications

The prevalence of mental disorders in the United States is approximately 30 percent. The global burden of disease statistics shows that four of the ten most important causes of disease worldwide are psychiatric in origin. The pathophysiology behind psychiatric disorders is the imbalance of the complex neurotransmitter system in the brain.  The mainstay of treatment for depression and anxiety has been therapies to modulate these neuron transmitters, including selective serotonin reuptake inhibitors (SSRI), mixed norepinephrine/serotonin reuptake inhibitors (SNRI), tricyclic antidepressants (TCA), and monoamine oxidase inhibitors (MAOI). This article will focus on venlafaxine, which belongs to the class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs).[1]

Venlafaxine is FDA approved to treat and manage symptoms of depression, social anxiety disorder,  and cataplexy.  Off-label, venlafaxine can be used for attention deficit disorder, fibromyalgia, diabetic neuropathy, complex pain syndromes, hot flashes, migraine prevention, post-traumatic stress disorder, obsessive-compulsive disorder, and premenstrual dysphoric disorder.  Venlafaxine may be used independently or as part of combination therapy with other drugs.[2]

Mechanism of Action

Venlafaxine works by increasing serotonin levels, norepinephrine, and dopamine in the brain by blocking transport proteins and stopping their reuptake at the presynaptic terminal. This action leads to more transmitters available at the synapse and ultimately increases the stimulation of postsynaptic receptors. SNRIs act primarily upon serotonergic and noradrenergic neurons but have little or no effect upon cholinergic or histaminergic receptors. Venlafaxine is a bicyclic phenylethylamine compound.[3] Venlafaxine is a more potent inhibitor of serotonin reuptake than norepinephrine reuptake. Venlafaxine is essentially a selective serotonin reuptake inhibitor at 75 mg, and with higher doses such as 225 mg/day, it has significant effects on the norepinephrine transporter in addition to serotonin.

Administration

Venlafaxine is prescribed only for those 18 years and older and should not be used in children under 18. Venlafaxine should be taken with food, and patients should not take it with alcohol as combining alcohol and venlafaxine can lead to increased sedation. 

Venlafaxine comes in an oral tablet and an oral capsule. The oral tablets come in immediate-release (25 mg, 37.5 mg, 50 mg, 75 mg and 100 mg) and extended-release forms (37.5 mg, 75 mg, 150 mg, and 225 mg.) The immediate-release tablet can be cut or crushed, but the extended-release tablet may not be. Treatment for depression for the immediate release oral table typically starts at 75 mg total per day, given in two or three divided doses.[4] Dosage can increase to 150 mg per day, with a maximum dose of 375 mg per day. The typical starting dose of the extended-release oral tablet is 75 mg per day, taken as a single dose in the morning or evening. This dose can be increased by 75 mg every four days until reaching the maximum dose of 225 mg per day.

Adverse Effects

Venlafaxine causes a lower frequency of anticholinergic, sedating, and cardiovascular side effects but a higher incidence of gastrointestinal complaints, sleep impairment, and sexual dysfunction than TCAs. Additionally, venlafaxine may impair sexual function, resulting in diminished libido, impotence, or difficulty achieving orgasm. Sexual dysfunction frequently results in noncompliance and should be asked about specifically. Sexual dysfunction can sometimes be ameliorated by lowering the dose or instituting drug-free weekends and holidays in appropriate patients. Some patients find withdrawal symptoms uncomfortable.[5]  

Common side effects include: 

• Headache

• Nausea

• Insomnia, dizziness, hypotension, anorexia, somnolence

• Xerostomia

• Asthenia

• HTN

• Impotence, decreased libido, and/or anorgasmia

• Constipation

• Weight loss

• Abnormal dreams

• Diarrhea, abdominal pain

• Blurred vision

• Anxiety, tremor

• Hypercholesterolemia

• Hyponatremia

• Serotonin syndrome[6]

• Seizures

There is an FDA black box warning against venlafaxine as it can increase suicidality, cause depression exacerbation, hypomania/mania, and serotonin syndrome. Venlafaxine can also cause abnormal bleeding, altered platelet function, and anaphylaxis/anaphylactoid reaction. Venlafaxine can cause fatal skin conditions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and erythema multiforme. Venlafaxine can also cause deterioration of glaucoma angle closure and seizures.[7] Venlafaxine has implications linking it to SIADH, HTN, arrhythmia, interstitial lung disease, eosinophilic pneumonia, pancreatitis, and hepatotoxicity. One main concern with SSRIs and SNRIs is the risk of serotonin syndrome, thought to result from hyperstimulation of brainstem 5HT-1A receptors.[8]

Contraindications

Contraindications to venlafaxine include concurrent use of monoamine oxidase inhibitors. Clinicians should not use venlafaxine if there is a history of anaphylaxis, and caution is necessary when combining venlafaxine with other serotonin modulators. Venlafaxine should be used cautiously with other sedating medications such as CNS depressants and alcohol use. Venlafaxine is contraindicated if it causes worsening suicidal ideation, depression, anxiety, and psychosis. Caution is advisable in heart failure patients, hyperthyroidism, and those with recent myocardial infarctions as it can raise blood pressure and increase heart rate. Venlafaxine raises the risk of seizures, and prescribers should avoid the drug in patients with a seizure disorder.[9] Venlafaxine can cause pupillary dilation and block the flow of fluid in the eye, leading to increased ocular pressure. Patients with glaucoma should have their eye pressures regularly monitored while taking venlafaxine. Venlafaxine is contraindicated in patients with uncontrolled angle-closure glaucoma.  Venlafaxine is a category C pregnancy drug. Venlafaxine can potentially pass into breast milk and cause side effects in breastfed children and should not be used in pregnancy and breastfeeding.

Monitoring

Venlafaxine can interact with many other medications, vitamins, or herbs.[10] Concurrent use of these agents can cause dangerous effects and are contraindicated with venlafaxine. The following is a brief list of drug interactions with venlafaxine:

• Patients should not take venlafaxine with monoamine oxidase inhibitors (MAOIs), linezolid, and methylene blue.  

• Caution is necessary when using venlafaxine with other drugs that can increase serotonin levels, including SSRIs, SNRIs, and tramadol, as they can lead to life-threatening serotonin syndrome. Other drugs that can raise serotonin include triptans, such as sumatriptan, rizatriptan, and zolmitriptan.

• Venlafaxine should not be combined with drugs for weight loss, such as phentermine. Using venlafaxine with drugs like phentermine may result in excessive weight loss, serotonin syndrome, and heart problems such as tachycardia and hypertension. 

• Venlafaxine with cimetidine raises the risk of high blood pressure or liver disease.

• Venlafaxine with haloperidol raises the risk of QT prolongation.[11]

• Venlafaxine taken with warfarin and anti-inflammatory drugs such as aspirin, ibuprofen, naproxen (NSAIDs) increase the risk of bleeding.

• Ritonavir, clarithromycin, or ketoconazole can inhibit the breakdown of venlafaxine leading to venlafaxine accumulation in the body.  

• Venlafaxine, taken with zolpidem, lorazepam, and diphenhydramine, can lead to increased sedation. 

• Metoprolol may be less effective when taken with venlafaxine.

• Venlafaxine can cause false positives when testing the patient’s urine for phencyclidine (PCP) and amphetamine. This effect may remain for several days after stopping venlafaxine.

Toxicity

Venlafaxine oral tablet is prescribed for long-term treatment, and it comes with serious risks if not taken as prescribed or stop it abruptly. Abrupt cessation of venlafaxine can lead to serious adverse effects such as irritability, tiredness, restlessness, anxiety,  insomnia, trouble sleeping, nightmares, headache, sweating, dizziness, tingling, or “pins and needles” feeling, shaking, confusion, nausea, vomiting, or diarrhea.  Symptoms of an overdose of venlafaxine can include: tachycardia, unusual sleepiness, dilated pupils, seizures, vomiting, cardiac arrhythmias, hypotension, muscle aches or pains, or dizziness.

Severe toxicity of venlafaxine, especially when combined with other antidepressants such as SSRI, SNRI, or MAOI, can lead to serotonin syndrome. Serotonin syndrome is a possibly life-threatening condition associated with increased serotonergic activity in the central nervous system. Serotonin syndrome may present with a spectrum of clinical findings, including autonomic hyperactivity, mental status changes, and neuromuscular abnormalities. Serotonin syndrome characteristically presents with myoclonus, agitation, abdominal cramping, hyperpyrexia, hypertension, and potentially death. No laboratory tests exist to confirm the diagnosis as serotonin concentrations do not correlate clinically with symptoms. Hunter Toxicity Criteria Decision Rules can be used to form the diagnosis.[12] To meet the criteria, the patient must be taking a serotonergic agent and fulfill one of the following conditions patients must exhibit spontaneous clonus

• An inducible clonus must be present, plus agitation or diaphoresis

• The presence of ocular clonus plus agitation or diaphoresis

• Tremor with hyperreflexia

• Hypertonia with a temperature above 38 degrees C plus ocular clonus or inducible clonus

Management of serotonin syndrome involves prompt discontinuation of all serotonergic agents with supportive care aimed at normalizing hemodynamics. Patient sedation with benzodiazepines and serotonin antagonists may also be an option.[8] Cyproheptadine can be an option in the event of a failure with benzodiazepines and supportive care. Cyproheptadine is a histamine-1 receptor antagonist with nonspecific 5-HT1A and 5-HT2A antagonistic properties, with an initial dose of 8 mg. treatment with propranolol, bromocriptine, or dantrolene is not recommended. Serotonin syndrome symptoms usually resolve within 24 hours of discontinuation of the offending agent.

Enhancing Healthcare Team Outcomes

Interprofessional healthcare team members should check the patient’s blood pressure before starting the medication and, additionally, continue to monitor blood pressure while on venlafaxine. Patients on venlafaxine should also have their renal function, and lipid profiles monitored. Close monitoring of psychiatric disorders, including symptoms of suicidality, depression, mania, anxiety, or unusual behavior changes, is a necessary precaution. Exercise care when transitioning from or to monoamine oxidase inhibitors. Do not start venlafaxine within two weeks of stopping an MAOI, and MAOI therapy should not commence within seven days of stopping venlafaxine. Only through close monitoring of the patient can the adverse effects be avoided. This monitoring should have contributions from all clinicians (MDs, DOs, NPs, PAs), nursing staff, and pharmacists, who need to coordinate their activities and openly share patient information to drive therapeutic decisions, minimize adverse events, drug-drug interactions, and optimizing patient outcomes. [Level 5]

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References

1.

Strawn JR, Geracioti L, Rajdev N, Clemenza K, Levine A. Pharmacotherapy for generalized anxiety disorder in adult and pediatric patients: an evidence-based treatment review. Expert Opin Pharmacother. 2018 Jul;19(10):1057-1070. [PMC free article: PMC6340395] [PubMed: 30056792]

2.

Safarova TP, Yakovleva OB, Sheshenin VS, Gavrilova SI. [Methods of augmentation of antidepressant therapy (on the model of complex therapy with the inclusion of actovegin) in gerontopsychiatric hospital]. Zh Nevrol Psikhiatr Im S S Korsakova. 2018;118(6. Vyp. 2):55-63. [PubMed: 30346435]

3.

Saad MA, El-Sahar AE, Sayed RH, Elbaz EM, Helmy HS, Senousy MA. Venlafaxine Mitigates Depressive-Like Behavior in Ovariectomized Rats by Activating the EPO/EPOR/JAK2 Signaling Pathway and Increasing the Serum Estradiol Level. Neurotherapeutics. 2019 Apr;16(2):404-415. [PMC free article: PMC6554373] [PubMed: 30361931]

4.

Fava GA, Benasi G, Lucente M, Offidani E, Cosci F, Guidi J. Withdrawal Symptoms after Serotonin-Noradrenaline Reuptake Inhibitor Discontinuation: Systematic Review. Psychother Psychosom. 2018;87(4):195-203. [PubMed: 30016772]

5.

Ning J, Luo J, Meng Z, Luo C, Wan G, Liu J, Wang S, Lian X, Melgiri ND, Sun Y, Huang R. The efficacy and safety of first-line therapies for preventing chronic post-surgical pain: a network meta-analysis. Oncotarget. 2018 Aug 10;9(62):32081-32095. [PMC free article: PMC6112831] [PubMed: 30174798]

6.

Zhan Z, Cao CS, Huang L. Serotonin Syndrome Induced by a Single Dose of Venlafaxine and Magnesium Valproate. Psychiatr Danub. 2021 Summer;33(2):193-195. [PubMed: 34185746]

7.

Dubovicky M, Belovicova K, Csatlosova K, Bogi E. Risks of using SSRI / SNRI antidepressants during pregnancy and lactation. Interdiscip Toxicol. 2017 Sep;10(1):30-34. [PMC free article: PMC6096863] [PubMed: 30123033]

8.

Schoretsanitis G, Augustin M, Saßmannshausen H, Franz C, Gründer G, Paulzen M. Antidepressants in breast milk; comparative analysis of excretion ratios. Arch Womens Ment Health. 2019 Jun;22(3):383-390. [PubMed: 30116895]

9.

Gallagher HC, Gallagher RM, Butler M, Buggy DJ, Henman MC. Venlafaxine for neuropathic pain in adults. Cochrane Database Syst Rev. 2015 Aug 23;2015(8):CD011091. [PMC free article: PMC6481532] [PubMed: 26298465]

10.

Woroń J, Siwek M, Gorostowicz A. Adverse effects of interactions between antidepressants and medications used in treatment of cardiovascular disorders. Psychiatr Pol. 2019 Oct 30;53(5):977-995. [PubMed: 31955180]

11.

Sertraline and venlafaxine: new indication. Prevention of recurrent depression: no advance. Prescrire Int. 2005 Feb;14(75):19-20. [PubMed: 15751171]

12.

Drugs and Lactation Database (LactMed®) [Internet]. National Institute of Child Health and Human Development; Bethesda (MD): Mar 15, 2023. Venlafaxine. [PubMed: 30000251]

Disclosure: Dharminder Singh declares no relevant financial relationships with ineligible companies.

Disclosure: Abdolreza Saadabadi declares no relevant financial relationships with ineligible companies.

Use of the antidepressant venlafaxine in patients with chronic pain | Kamchatnov P.R., Radysh B.B., Kutenev A.V., Kazakov A.Yu.

Use of the antidepressant venlafaxine in patients with chronic pain

September 03, 2009

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• Kamchatnov P.R.

  1

,

• Radysh B.B.

,

• Kutenev A.V.

,

• Kazakov A. Yu.

  1

1

RNIMU them. N.I. Pirogov of the Ministry of Health of Russia, Moscow, Russia

For citation: Kamchatnov P.R., Radysh B.B., Kutenev A.V., Kazakov A.Yu. Use of the antidepressant venlafaxine in patients with chronic pain syndrome. breast cancer. 2009;20:1382.

Chronic pain that lasts longer than necessary for normal healing and persists for more than 12 weeks is a fairly common condition in the population. The results of a population study conducted in Europe, which included 50 thousand people, allow us to state that every fifth adult suffers from severe or moderate chronic pain [8]. It turned out that the most common causes of chronic pain syndrome are diseases of the musculoskeletal system – lesions of bones, joints, periarticular tissues. The vast majority of respondents who confirmed the presence of chronic pain receive systematic pain treatment, but more than half of them do not believe that the therapy is quite effective.

Chronic pain that lasts longer than necessary for normal healing and persists for more than 12 weeks is a fairly common condition in the population. The results of a population study conducted in Europe, which included 50 thousand people, allow us to state that every fifth adult suffers from severe or moderate chronic pain [8]. It turned out that the most common causes of chronic pain syndrome are diseases of the musculoskeletal system – lesions of bones, joints, periarticular tissues. The vast majority of respondents who confirmed the presence of chronic pain receive systematic pain treatment, but more than half of them do not believe that the therapy is quite effective.
A serious problem is neuropathic pain, the occurrence of which is caused by a direct lesion of the somatosensory system and is not associated with irritation of pain receptors. The results of epidemiological studies suggest that at least 3% of the members of the population experience neuropathic pain, although there are data on its wider prevalence [25]. According to modern views on the pathophysiology of neuropathic pain, the lesion that causes it can be localized at different levels of the peripheral or central nervous system [1,5]. The developing complex restructuring of the nervous system leads to the formation of a pathological algic system that ensures the existence of a persistent pain syndrome.
An important role in the formation of neuropathic pain syndrome is played by the dysfunction of the mechanisms of perception and processing of pain impulses [4]. Of great importance is also a decrease in the activity of the body’s own anti-pain systems, in particular, the pathways emanating from the nuclei of the brain stem (in particular, the periaqueductal gray matter), the neurotransmitters in which are serotonin and norepinephrine [19]. Violation of the functioning of this system is of great importance for the occurrence of chronic pain syndromes due to various reasons.
Taking into account the complex pathophysiological mechanisms of the formation of chronic pain, neuropathic pain syndromes, painkillers (for example, paracetamol) and non-steroidal anti-inflammatory drugs are not always effective for their relief. Moreover, their extremely low efficacy in true neuropathic pain has been established. At the same time, the results of repeated surveys of medical workers indicate that it is non-steroidal anti-inflammatory drugs that are most often prescribed to this group of patients. It should be borne in mind that their long-term, often uncontrolled use is associated with a high risk of complications, including severe ones, the most common of which are lesions of the gastric mucosa with ulceration, increased blood pressure, and an increased risk of atherothrombotic complications [8,20 ].
The results of a number of experimental works and clinical studies indicate that today the optimal approach to the treatment of such patients is the use of antidepressants and antiepileptic drugs. There is sufficient experience in the clinical use of antidepressants for the relief of pain in patients with neuropathic pain and chronic pain syndromes. For this purpose, tricyclic antidepressants are most widely used, and the maximum experience gained in the conditions of randomized clinical trials has been accumulated in relation to amitriptyline.
Based on the results of a meta-analysis of 19 double-blind randomized clinical trials (a total of 2515 patients with neuropathic pain syndromes, excluding headaches and migraine), it was found that antidepressants are most effective against neuropathic pain syndromes caused by distal pain diabetic polyneuropathy and postherpetic neuralgia. This group of drugs was less effective against pain syndromes caused by HIV infection and some other clinical conditions [24]. The authors of the cited meta-analysis, like most other researchers, note that in order to achieve a therapeutic effect, the use of drugs in high doses is often required, which is associated with an increased risk of side effects. In particular, this complicates the widespread use of drugs on an outpatient basis, reduces the adherence of patients to treatment.
For the treatment of patients with neuropathic pain, chronic pain syndromes, in addition to tricyclic antidepressants, drugs from the group of serotonin reuptake inhibitors are also used, which, in addition, when administered in therapeutic doses, have the ability to suppress the reuptake and noradrenaline – drugs “dual action”, representative which is venlafaxine (Velafax) [19].
The results of experimental studies convincingly prove that venlafaxine has its own analgesic activity, which is not related to its antidepressant properties. Thus, the positive effect of venlafaxine, associated with the peculiarities of its chemical structure, is observed in patients with chronic pain syndromes associated with depressive disorders, and without them [7]. Interestingly, in some cases, the analgesic effect occurs when using doses of the drug that are smaller than those that cause the actual antidepressant effect. It is also believed that the analgesic effect in this situation is due to the interaction of the drug with both serotonin and norepinephrine receptors, and modulation of the synaptic uptake of mediators by dopamine can play a significant role. In addition, there is evidence that the analgesic effect of the drug to a certain extent can be explained by its interaction with opioid systems (primarily with

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