Venlafaxine

Generic name: venlafaxine hydrochloride · Brand names: Effexor, Effexor XR

Quick facts

Drug class
Section
Description
Source
DailyMed label (Avet)
Medlineplus text
Venlafaxine is in a class of medications called selective serotonin and norepinephrine reuptake inhibitors (SNRIs).
Medlineplus source
MedlinePlus Why is this medication prescribed?
Source text (exact source wording)
Venlafaxine hydrochloride, USP is a structurally novel antidepressant for oral administration.
Rx or otc
Value
Rx
Section
Label title
Source
DailyMed label (Avet)
Source text (exact source wording)
Venlafaxine Tablets, USP Rx only
Forms and strengths
Section
Description
Source
DailyMed label (Avet)
Source text (exact source wording)
Compressed tablets contain venlafaxine hydrochloride, USP equivalent to 25 mg, 37.5 mg, 50 mg, 75 mg, or 100 mg venlafaxine.
Generic available
Value
yes
Source
DailyMed label (Avet)
Source text (exact source wording)
Label is for Venlafaxine Tablets, USP, manufactured for Avet Pharmaceuticals Inc. (generic labeler); marketing category not captured from the page text
Common use one line
Used to treat major depressive disorder.

What it is used for

Venlafaxine tablets are indicated to treat major depressive disorder. MedlinePlus also lists anxiety and panic uses, but those apply to the venlafaxine product family (including the extended-release capsule); the tablet label itself lists major depressive disorder.
Section
Indications and Usage
Source
DailyMed label (Avet)
Medlineplus text
Venlafaxine is used to treat depression, generalized anxiety disorder (GAD; excessive worrying that is difficult to control), social anxiety disorder (extreme fear of interacting with others or performing in front of others that interferes with normal life), and panic disorder (sudden, unexpected attacks of extreme fear and worry about these attacks).
Medlineplus source
MedlinePlus Why is this medication prescribed? (covers tablets and extended-release capsules together)
Source text (exact source wording)
Venlafaxine tablets, USP is indicated for the treatment of major depressive disorder.

How it works

Venlafaxine is believed to work by boosting brain chemical activity. Its active product, ODV, strongly blocks the reuptake of serotonin and norepinephrine and weakly blocks dopamine reuptake.
Section
Clinical Pharmacology: Pharmacodynamics (first two sentences)
Source
DailyMed label (Avet)
Source text (exact source wording)
The mechanism of the antidepressant action of venlafaxine in humans is believed to be associated with its potentiation of neurotransmitter activity in the CNS. Preclinical studies have shown that venlafaxine and its active metabolite, O-desmethylvenlafaxine (ODV), are potent inhibitors of neuronal serotonin and norepinephrine reuptake and weak inhibitors of dopamine reuptake.

Dosage: adults

The recommended starting dose is 75 mg/day, in two or three divided doses with food. The dose may be raised to 150 mg/day and then up to 225 mg/day, with increases of up to 75 mg/day at intervals of no less than 4 days. Some patients, including more severely depressed ones, may respond more to higher doses, up to a maximum of 375 mg/day.
Section
Dosage and Administration: Initial Treatment
Source
DailyMed label (Avet)
Source text (exact source wording)
The recommended starting dose for venlafaxine tablets, USP is 75 mg/day, administered in two or three divided doses, taken with food. Depending on tolerability and the need for further clinical effect, the dose may be increased to 150 mg/day. If needed, the dose should be further increased up to 225 mg/day. When increasing the dose, increments of up to 75 mg/day should be made at intervals of no less than 4 days. In outpatient settings there was no evidence of usefulness of doses greater than 225 mg/day for moderately depressed patients, but more severely depressed inpatients responded to a mean dose of 350 mg/day. Certain patients, including more severely depressed patients, may therefore respond more to higher doses, up to a maximum of 375 mg/day, generally in three divided doses (see PRECAUTIONS, General, Use in Patients with Concomitant Illness).

Dosage: children

Safety and effectiveness in children have not been established, and venlafaxine tablets are not approved for use in pediatric patients.
Section
Precautions: Pediatric Use; Boxed Warning (last sentence of first paragraph, joined)
Source
DailyMed label (Avet)
Source text (exact source wording)
Safety and effectiveness in the pediatric population have not been established (see BOX WARNING and WARNINGS, Clinical Worsening and Suicide Risk). Venlafaxine hydrochloride tablets are not approved for use in pediatric patients.

Dosage adjustments

Kidney
For mild to moderate kidney impairment (GFR 10 to 70 mL/min) the label recommends reducing the total daily dose by 25%. For people on hemodialysis, it recommends reducing it by 50%.
Section
Dosage and Administration: Dosage for Patients with Renal Impairment
Source
DailyMed label (Avet)
Source text (exact source wording)
Given the decrease in clearance for venlafaxine and the increase in elimination half-life for both venlafaxine and ODV that is observed in patients with renal impairment (GFR = 10 to 70 mL/min) compared to normals (see CLINICAL PHARMACOLOGY), it is recommended that the total daily dose be reduced by 25% in patients with mild to moderate renal impairment. It is recommended that the total daily dose be reduced by 50% in patients undergoing hemodialysis.
Liver
For mild to moderate liver impairment the label recommends reducing the total daily dose by 50%, and more than 50% may be needed for some people with cirrhosis.
Section
Dosage and Administration: Dosage for Patients with Hepatic Impairment
Source
DailyMed label (Avet)
Source text (exact source wording)
It is recommended that the total daily dose be reduced by 50% in patients with mild to moderate hepatic impairment. Since there was much individual variability in clearance between subjects with cirrhosis, it may be necessary to reduce the dose even more than 50%, and individualization of dosing may be desirable in some patients.
Elderly
No dose change is recommended for older adults based on age alone, but extra care should be taken when raising the dose.
Section
Dosage and Administration: Dosage for Elderly Patients
Source
DailyMed label (Avet)
Source text (exact source wording)
No dose adjustment is recommended for elderly patients on the basis of age. As with any antidepressant, however, caution should be exercised in treating the elderly. When individualizing the dosage, extra care should be taken when increasing the dose.

Missed dose

Take a missed dose as soon as you remember. If it is almost time for the next dose, skip it. Do not take a double dose.
Section
What should I do if I forget a dose?
Source
MedlinePlus (https://medlineplus.gov/druginfo/meds/a694020.html), Last Revised 10/15/2025. The tablet label body has no missed-dose section.
Source text (exact source wording)
Take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are taking the extended-release capsules, do not take more than one dose per day.

Overdose

Overdoses have mostly involved alcohol or other drugs. Reported effects include fast heartbeat, drowsiness to coma, large pupils, seizures, vomiting, heart rhythm changes, low blood pressure, serotonin syndrome and death. No specific antidote is known. Call poison control at 1-800-222-1222, or 911 if the person has collapsed, had a seizure, has trouble breathing or cannot be woken.
Section
Overdosage (Human Experience paragraph 2; Management of Overdosage last sentence of paragraph 2)
Source
DailyMed label (Avet)
Medlineplus text
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
Medlineplus source
MedlinePlus In case of emergency/overdose
Source text (exact source wording)
In postmarketing experience, overdose with venlafaxine has occurred predominantly in combination with alcohol and/or other drugs. The most commonly reported events in overdosage include tachycardia, changes in level of consciousness (ranging from somnolence to coma), mydriasis, seizures, and vomiting. Electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), ventricular tachycardia, bradycardia, hypotension, rhabdomyolysis, vertigo, liver necrosis, serotonin syndrome, and death have been reported. No specific antidotes for venlafaxine are known.

Storage

Store at 20° to 25°C (68° to 77°F) in a dry place, in a tight, light-resistant container, and keep out of the reach of children.
Section
How Supplied
Source
DailyMed label (Avet); labeler-specific
Source text (exact source wording)
Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature] in a dry place. Dispense in a tight, light-resistant container as defined in the USP, with a child resistant closure (as required). KEEP THIS AND ALL MEDICATION OUT OF THE REACH OF CHILDREN.

Boxed warning

Antidepressants raised the risk of suicidal thoughts and behavior in children, teens and young adults in short-term studies. Studies did not show higher risk in adults beyond age 24, and showed lower risk in adults aged 65 and older. Anyone starting an antidepressant should be watched closely for worsening, suicidal thoughts or unusual behavior changes, and families should be told to watch too. Venlafaxine tablets are not approved for children.
Title
Suicidality and Antidepressant Drugs
Section
Boxed warning (top of label)
Source
DailyMed label (Avet)
Source text verbatim (exact source wording)
Suicidality and Antidepressant Drugs

Antidepressants increased the risk compared to placebo of suicidal thinking and behavior (suicidality) in children, adolescents, and young adults in short-term studies of Major Depressive Disorder (MDD) and other psychiatric disorders. Anyone considering the use of venlafaxine hydrochloride or any other antidepressant in a child, adolescent, or young adult must balance this risk with the clinical need. Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24; there was a reduction in risk with antidepressants compared to placebo in adults aged 65 and older. Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide. Patients of all ages who are started on antidepressant therapy should be monitored appropriately and observed closely for clinical worsening, suicidality, or unusual changes in behavior. Families and caregivers should be advised of the need for close observation and communication with the prescriber. Venlafaxine hydrochloride tablets are not approved for use in pediatric patients. (See WARNINGS: Clinical Worsening and Suicide Risk; PRECAUTIONS, Information for Patients; and PRECAUTIONS, Pediatric Use).

Contraindications

Do not use venlafaxine if you are allergic to it or its ingredients. Do not use it with MAOIs for psychiatric conditions, or within 7 days of stopping venlafaxine before an MAOI, or within 14 days of stopping an MAOI. Do not start it in someone being treated with linezolid or intravenous methylene blue, because of the risk of serotonin syndrome.
Section
Contraindications
Source
DailyMed label (Avet)
Source text (exact source wording)
Hypersensitivity to venlafaxine hydrochloride or to any excipients in the formulation. The use of MAOIs intended to treat psychiatric disorders with venlafaxine hydrochloride or within 7 days of stopping treatment with venlafaxine hydrochloride is contraindicated because of an increased risk of serotonin syndrome. The use of venlafaxine hydrochloride within 14 days of stopping an MAOI intended to treat psychiatric disorders is also contraindicated (see WARNINGS and DOSAGE AND ADMINISTRATION). Starting venlafaxine hydrochloride in a patient who is being treated with MAOIs such as linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome (see WARNINGS and DOSAGE AND ADMINISTRATION).

Warnings and precautions

Depression can worsen, and suicidal thoughts can appear, whether or not a person takes an antidepressant. Patients should be watched closely, especially in the first few months and when the dose changes. Prescriptions should be written for the smallest quantity consistent with good care to reduce overdose risk. Per 1,000 patients treated, the label shows 14 additional cases under age 18, 5 additional at 18 to 24, 1 fewer at 25 to 64 and 6 fewer at 65 or older.
Heading
Clinical Worsening and Suicide Risk
Section
Warnings (selected sentences in label order). Table 1 in the label: age < 18: 14 additional cases; 18 to 24: 5 additional cases; 25 to 64: 1 fewer case; ≥ 65: 6 fewer cases per 1,000 patients treated.
Source
DailyMed label (Avet)
Source text (exact source wording)
Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications, and this risk may persist until significant remission occurs. All patients being treated with antidepressants for any indication should be monitored appropriately and observed closely for clinical worsening, suicidality, and unusual changes in behavior, especially during the initial few months of a course of drug therapy, or at times of dose changes, either increases or decreases. Prescriptions for venlafaxine tablets should be written for the smallest quantity of tablets consistent with good patient management, in order to reduce the risk of overdose.
A depressive episode may be the first sign of bipolar disorder. Venlafaxine tablets are not approved for bipolar depression.
Heading
Screening Patients for Bipolar Disorder
Section
Warnings (first and last sentences of paragraph)
Source
DailyMed label (Avet)
Source text (exact source wording)
A major depressive episode may be the initial presentation of bipolar disorder. It should be noted that venlafaxine tablets are not approved for use in treating bipolar depression.
Serotonin syndrome, which can be life-threatening, has been reported with venlafaxine, especially with other serotonin-related drugs such as triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines and St. John's Wort, and with MAOIs, linezolid and intravenous methylene blue. Symptoms can include agitation, hallucinations, coma, fast heartbeat, unstable blood pressure, tremor, rigidity, seizures, nausea, vomiting and diarrhea.
Heading
Serotonin Syndrome
Section
Warnings: Serotonin Syndrome (paragraphs 1 and 2)
Source
DailyMed label (Avet)
Source text (exact source wording)
The development of a potentially life-threatening serotonin syndrome has been reported with SNRIs and SSRIs, including venlafaxine hydrochloride, alone but particularly with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines and St. John's Wort) and with drugs that impair metabolism of serotonin (in particular, MAOIs, both those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea).
Pupil widening from venlafaxine may trigger an angle-closure glaucoma attack in people with anatomically narrow eye angles.
Heading
Angle-Closure Glaucoma
Section
Warnings
Source
DailyMed label (Avet)
Source text (exact source wording)
The pupillary dilation that occurs following use of many antidepressant drugs including venlafaxine tablets may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy.
Venlafaxine can cause sustained high blood pressure in some people. Existing high blood pressure should be controlled first and blood pressure checked regularly. Sustained elevation occurred in 3% at less than 100 mg/day, 5% at 101 to 200 mg/day, 7% at 201 to 300 mg/day and 13% above 300 mg/day, versus 2% on placebo.
Heading
Sustained Hypertension
Section
Warnings (selected sentences in label order). Table: sustained elevation in SDBP: < 100 mg/day 3%; 101 to 200 mg/day 5%; 201 to 300 mg/day 7%; > 300 mg/day 13%; Placebo 2%.
Source
DailyMed label (Avet)
Source text (exact source wording)
Venlafaxine treatment is associated with sustained increases in blood pressure in some patients. Pre-existing hypertension should be controlled before treatment with venlafaxine. It is recommended that patients receiving venlafaxine have regular monitoring of blood pressure. For patients who experience a sustained increase in blood pressure while receiving venlafaxine, either dose reduction or discontinuation should be considered.
Venlafaxine may cause sexual problems: in men, delayed or failed ejaculation, lower sex drive and erectile dysfunction; in women, lower sex drive and delayed or absent orgasm.
Heading
Sexual Dysfunction
Section
Warnings
Source
DailyMed label (Avet)
Source text (exact source wording)
Use of SNRIs, including venlafaxine hydrochloride, may cause symptoms of sexual dysfunction (see ADVERSE REACTIONS). In male patients, SNRI use may result in ejaculatory delay or failure, decreased libido, and erectile dysfunction. In female patients, SNRI use may result in decreased libido and delayed or absent orgasm.
Stopping suddenly or lowering the dose quickly can cause new symptoms, and they are more frequent with higher doses and longer treatment. A gradual dose reduction is recommended whenever possible.
Heading
Discontinuation of Treatment
Section
Precautions: General: Discontinuation of Treatment (selected sentences)
Source
DailyMed label (Avet)
Source text (exact source wording)
Abrupt discontinuation or dose reduction of venlafaxine at various doses has been found to be associated with the appearance of new symptoms, the frequency of which increased with increased dose level and with longer duration of treatment. A gradual reduction in the dose rather than abrupt cessation is recommended whenever possible.
Low blood sodium can happen with venlafaxine. Older people, people taking diuretics and people low on body fluid may be at greater risk.
Heading
Hyponatremia
Section
Precautions: General (selected sentences)
Source
DailyMed label (Avet)
Source text (exact source wording)
Hyponatremia may occur as a result of treatment with SSRIs and SNRIs, including venlafaxine hydrochloride. Elderly patients may be at greater risk of developing hyponatremia with SSRIs and SNRIs. Also, patients taking diuretics or who are otherwise volume depleted may be at greater risk.
Seizures occurred in 0.26% (8 of 3,082) of treated patients before approval. Use caution with a history of seizures and stop the drug if seizures develop.
Heading
Seizures
Section
Precautions: General (selected sentences)
Source
DailyMed label (Avet)
Source text (exact source wording)
During premarketing testing, seizures were reported in 0.26 % (8/3,082) of venlafaxine-treated patients. Venlafaxine hydrochloride should be used cautiously in patients with a history of seizures. It should be discontinued in any patient who develops seizures.
Venlafaxine may increase the risk of bleeding, and aspirin, NSAIDs, warfarin and other anticoagulants may add to this risk.
Heading
Abnormal Bleeding
Section
Precautions: General (first two sentences)
Source
DailyMed label (Avet)
Source text (exact source wording)
SSRIs and SNRIs, including venlafaxine hydrochloride, may increase the risk of bleeding events. Concomitant use of aspirin, non-steroidal anti-inflammatory drugs, warfarin, and other anti-coagulants may add to this risk.
Mania or hypomania occurred in 0.5% of treated patients. Use caution with a history of mania.
Heading
Activation of Mania/Hypomania
Section
Precautions: General (selected sentences)
Source
DailyMed label (Avet)
Source text (exact source wording)
During Phase 2 and Phase 3 trials, hypomania or mania occurred in 0.5% of patients treated with venlafaxine. As with all antidepressants, venlafaxine hydrochloride should be used cautiously in patients with a history of mania.
Clinically relevant cholesterol increases occurred in 5.3% of treated patients versus 0% on placebo. Cholesterol testing should be considered during long-term treatment.
Heading
Serum Cholesterol Elevation
Section
Precautions: General
Source
DailyMed label (Avet)
Source text (exact source wording)
Clinically relevant increases in serum cholesterol were recorded in 5.3% of venlafaxine-treated patients and 0% of placebo-treated patients treated for at least 3 months in placebo-controlled trials. Measurement of serum cholesterol levels should be considered during long-term treatment.

Pregnancy and breastfeeding

There are no adequate and well-controlled studies in pregnant women, so it should be used in pregnancy only if clearly needed. Newborns exposed late in the third trimester have had complications needing longer hospital stays, breathing support and tube feeding. Venlafaxine and ODV pass into breast milk, so a decision should be made whether to stop nursing or stop the drug.
Section
Precautions: Pregnancy (Teratogenic and Nonteratogenic Effects, selected sentences); Nursing Mothers
Source
DailyMed label (Avet)
Medlineplus text
tell your doctor if you are pregnant, especially if you are in the last few months of your pregnancy, or if you plan to become pregnant or are breast-feeding. If you become pregnant while taking venlafaxine, call your doctor.
Medlineplus source
MedlinePlus What special precautions should I follow?
Source text (exact source wording)
There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Neonates exposed to venlafaxine hydrochloride, other SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors), or SSRIs (Selective Serotonin Reuptake Inhibitors), late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Venlafaxine and ODV have been reported to be excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from venlafaxine hydrochloride, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Side effects

Common
The label lists these as the most commonly observed side effects (5% or more and at least twice the placebo rate): weakness, sweating, nausea, constipation, loss of appetite, vomiting, sleepiness, dry mouth, dizziness, nervousness, anxiety, tremor and blurred vision, plus abnormal ejaculation or orgasm and impotence in men.
Threshold
Label: incidence of 5% or greater and not seen at an equivalent incidence among placebo-treated patients (incidence at least twice that for placebo)
Section
Adverse Reactions: Commonly Observed Adverse Events in Controlled Clinical Trials
Source
DailyMed label (Avet)
Table note
Table 2 (venlafaxine n=1,033 vs placebo n=609): Nausea 37% vs 11%; Somnolence 23% vs 9%; Dry mouth 22% vs 11%; Dizziness 19% vs 7%; Constipation 15% vs 7%; Asthenia 12% vs 6%; Sweating 12% vs 3%; Abnormal ejaculation/orgasm 12% (men) ; Anorexia 11% vs 2%; Nervousness 13% vs 6%; Anxiety 6% vs 3%; Blurred vision 6% vs 2%; Vomiting 6% vs 2%; Tremor 5% vs 1%; Impotence 6% (men).
Source text (exact source wording)
The most commonly observed adverse events associated with the use of venlafaxine hydrochloride (incidence of 5% or greater) and not seen at an equivalent incidence among placebo-treated patients (ie, incidence for venlafaxine hydrochloride at least twice that for placebo), derived from the 1% incidence table below, were asthenia, sweating, nausea, constipation, anorexia, vomiting, somnolence, dry mouth, dizziness, nervousness, anxiety, tremor, and blurred vision as well as abnormal ejaculation/orgasm and impotence in men.
Less common
Other reported reactions include headache (25% vs 24% on placebo), trouble sleeping (18% vs 10%), diarrhea (8% vs 7%), indigestion (5% vs 4%), rash (3% vs 2%), increased blood pressure (2%), fast heartbeat (2%), lower sex drive (2%) and ringing in the ears (2%).
Section
Adverse Reactions, TABLE 2 Treatment-Emergent Adverse Experience Incidence in 4- to 8-Week Placebo-Controlled Clinical Trials (selected rows below the 'common' list criteria)
Source
DailyMed label (Avet)
Source text (exact source wording)
Table 2 (venlafaxine vs placebo): Headache 25% vs 24%; Infection 6% vs 5%; Insomnia 18% vs 10%; Diarrhea 8% vs 7%; Dyspepsia 5% vs 4%; Vasodilatation 4% vs 3%; Abnormal dreams 4% vs 3%; Rash 3% vs 2%; Flatulence 3% vs 2%; Chills 3%; Yawn 3%; Urinary frequency 3% vs 2%; Increased blood pressure / hypertension 2%; Tachycardia 2%; Postural hypotension 1%; Libido decreased 2%; Agitation 2%; Mydriasis 2%; Tinnitus 2%; Taste perversion 2%.
Serious
MedlinePlus says to call your doctor right away for rash, hives, itching, trouble breathing or swallowing, a fast, pounding or irregular heartbeat, chest pain, seizures, unusual bruising or bleeding, fever with confusion and stiff muscles, hallucinations or coma.
Label section
Warnings; Precautions (see those entries for verbatim text)
Label source
DailyMed label (Avet)
Medlineplus source
MedlinePlus What side effects can this medication cause?
Label source text (exact source wording)
Serotonin syndrome, angle-closure glaucoma, sustained hypertension, seizures, abnormal bleeding, hyponatremia, interstitial lung disease and eosinophilic pneumonia are described under Warnings and Precautions above. (Postmarketing Reports section NOT CAPTURED VERBATIM.)
Medlineplus source text (exact source wording)
Some side effects can be serious. If you experience any of the following symptoms or those listed in the IMPORTANT WARNING or SPECIAL PRECAUTIONS sections, call your doctor immediately: rash; hives; itching; difficulty breathing or swallowing; fast, pounding, or irregular heartbeat; difficulty breathing, cough, chest pain; seizures; unusual bruising or bleeding; fever, sweating, confusion, fast or irregular heartbeat, severe muscle stiffness or twitching, nausea, vomiting, or diarrhea; hallucinations (seeing things or hearing voices that do not exist); coma (loss of consciousness for a period of time)
Led to discontinuation
Nineteen percent (537 of 2,897) of patients in the depression studies stopped treatment because of a side effect. Nausea was the most common reason (6%), followed by sleepiness, insomnia, dizziness, abnormal ejaculation and headache (3% each).
Section
Adverse Reactions: Associated with Discontinuation of Treatment (table rows joined as text)
Source
DailyMed label (Avet)
Source text (exact source wording)
Nineteen percent (537/2,897) of venlafaxine patients in Phase 2 and Phase 3 depression studies discontinued treatment due to an adverse event. The more common events (≥1%) associated with discontinuation and considered to be drug-related (ie, those events associated with dropout at a rate approximately twice or greater for venlafaxine compared to placebo) included: Somnolence 3% (placebo 1%); Insomnia 3% (1%); Dizziness 3%; Nervousness 2%; Dry mouth 2%; Anxiety 2% (1%); Nausea 6% (1%); Abnormal ejaculation 3%; Headache 3% (1%); Asthenia 2%; Sweating 2%.

Interactions

Drugs
Wait at least 14 days after stopping an MAOI before starting venlafaxine, and at least 7 days after stopping venlafaxine before starting an MAOI. Do not start venlafaxine in someone treated with linezolid or intravenous methylene blue.
Name
MAOIs (including linezolid and intravenous methylene blue)
Section
Dosage and Administration: Switching a Patient To or From an MAOI
Source text (exact source wording)
At least 14 days should elapse between discontinuation of an MAOI intended to treat psychiatric disorders and initiation of therapy with venlafaxine tablets. Conversely, at least 7 days should be allowed after stopping venlafaxine tablets before starting an MAOI intended to treat psychiatric disorders (see CONTRAINDICATIONS). Do not start venlafaxine tablets in a patient who is being treated with linezolid or intravenous methylene blue because there is increased risk of serotonin syndrome.
Use caution when combining venlafaxine with triptans, lithium, opioids, amphetamines or St. John's Wort because of serotonin syndrome risk.
Name
Serotonergic drugs
Section
Precautions: Drug Interactions: Serotonergic Drugs
Source text (exact source wording)
Based on the mechanism of action of SNRIs and SSRIs, including venlafaxine hydrochloride, and the potential for serotonin syndrome, caution is advised when venlafaxine is co-administered with other drugs that may affect the serotonergic neurotransmitter systems, such as triptans, lithium, opioids, amphetamines, or St. John's Wort (see WARNINGS: Serotonin Syndrome).
Increased bleeding has been reported with warfarin. People on warfarin should be carefully monitored when venlafaxine is started or stopped.
Name
NSAIDs, aspirin and warfarin
Section
Precautions: Drug Interactions: Drugs that Interfere with Hemostasis
Source text (exact source wording)
Altered anticoagulant effects, including increased bleeding, have been reported when SSRIs and SNRIs are co-administered with warfarin. Patients receiving warfarin therapy should be carefully monitored when venlafaxine hydrochloride is initiated or discontinued.
Cimetidine reduced venlafaxine clearance by about 43% and raised exposure by about 60%. Caution is advised in people with high blood pressure, older people and people with liver problems.
Name
Cimetidine
Section
Precautions: Drug Interactions: Cimetidine
Source text (exact source wording)
The oral clearance of venlafaxine was reduced by about 43%, and the exposure (AUC) and maximum concentration (Cmax) of the drug were increased by about 60%. However, for patients with preexisting hypertension, and for elderly patients or patients with hepatic dysfunction, the interaction associated with the concomitant use of venlafaxine and cimetidine is not known and potentially could be more pronounced. Therefore, caution is advised with such patients.
Venlafaxine lowered haloperidol clearance by 42% and raised haloperidol exposure (AUC) by 70%.
Name
Haloperidol
Section
Precautions: Drug Interactions: Haloperidol
Source text (exact source wording)
Venlafaxine administered under steady-state conditions at 150 mg/day in 24 healthy subjects decreased total oral-dose clearance (Cl/F) of a single 2 mg dose of haloperidol by 42%, which resulted in a 70% increase in haloperidol AUC.
Venlafaxine raised metoprolol levels by about 30 to 40%. Caution should be exercised when using both.
Name
Metoprolol
Section
Precautions: Drug Interactions: Metoprolol
Source text (exact source wording)
Concomitant administration of venlafaxine (50 mg every 8 hours for 5 days) and metoprolol (100 mg every 24 hours for 5 days) to 18 healthy male subjects in a pharmacokinetic interaction study for both drugs resulted in an increase of plasma concentrations of metoprolol by approximately 30 to 40% without altering the plasma concentrations of its active metabolite, α-hydroxymetoprolol. Caution should be exercised with co-administration of venlafaxine and metoprolol.
CYP3A4 inhibitors may raise venlafaxine and ODV levels, so caution is advised.
Name
Ketoconazole and CYP3A4 inhibitors
Section
Precautions: Drug Interactions: Ketoconazole
Source text (exact source wording)
Concomitant use of CYP3A4 inhibitors and venlafaxine may increase levels of venlafaxine and ODV. Therefore, caution is advised if a patient's therapy includes a CYP3A4 inhibitor and venlafaxine concomitantly.
Venlafaxine lowered indinavir exposure by 28% (AUC) and peak level by 36%; the clinical significance is unknown.
Name
Indinavir
Section
Precautions: Drug Interactions: Indinavir
Source text (exact source wording)
In a study of 9 healthy volunteers, venlafaxine administered under steady-state conditions at 150 mg/day resulted in a 28% decrease in the AUC of a single 800 mg oral dose of indinavir and a 36% decrease in indinavir Cmax. Indinavir did not affect the pharmacokinetics of venlafaxine and ODV. The clinical significance of this finding is unknown.
Taking weight loss agents, including phentermine, with venlafaxine is not recommended.
Name
Weight loss agents including phentermine
Section
Precautions: General: Changes in Weight
Source text (exact source wording)
The safety and efficacy of venlafaxine therapy in combination with weight loss agents, including phentermine, have not been established. Co-administration of venlafaxine hydrochloride and weight loss agents is not recommended.
Desipramine levels rose about 35% with venlafaxine; clinical significance of related changes is unknown.
Name
Imipramine / desipramine
Section
Precautions: Drug Interactions: Imipramine
Source text (exact source wording)
Venlafaxine did not affect the pharmacokinetics of imipramine and 2-OH- imipramine. However, desipramine AUC, Cmax, and Cmin increased by about 35% in the presence of venlafaxine. The clinical significance of elevated 2-OH- desipramine levels is unknown.
Food and alcohol
Although venlafaxine has not been shown to worsen alcohol's effects on mental and motor skills, patients should avoid alcohol while taking it.
Name
Alcohol
Section
Precautions: Information for Patients: Alcohol
Source text (exact source wording)
Although venlafaxine hydrochloride has not been shown to increase the impairment of mental and motor skills caused by alcohol, patients should be advised to avoid alcohol while taking venlafaxine hydrochloride.
Name
Food
Section
Clinical Pharmacology: Pharmacokinetics
Source text (exact source wording)
Food has no significant effect on the absorption of venlafaxine or on the formation of ODV.
Other
St. John's wort, tryptophan and cimetidine may interact with venlafaxine. Do not start them without talking to your healthcare provider.
Name
St. John's wort, tryptophan, cimetidine (nonprescription/herbal)
Section
MedlinePlus What special precautions should I follow?
Source text (exact source wording)
the following nonprescription or herbal products may interact with venlafaxine: St. John's wort; tryptophan; cimetidine (Tagamet®).
Venlafaxine can cause false-positive urine screening tests for PCP and amphetamine.
Name
Urine drug screening
Section
Precautions: Drug-Laboratory Test Interactions
Source text (exact source wording)
False-positive urine immunoassay screening tests for phencyclidine (PCP) and amphetamine have been reported in patients taking venlafaxine.
Liverpool checkers
Label mentions indinavir (an antiviral protease inhibitor) in the interaction section; Liverpool HIV checker: not checked in this run.

Patient tips

Take it exactly as prescribed, with food, two or three times a day. Do not stop suddenly. Do not drive or run machinery until you know how it affects you. Tell your prescriber about rash or hives. Watch for new or worsening depression or suicidal thoughts, especially early in treatment.
Medlineplus source
MedlinePlus (https://medlineplus.gov/druginfo/meds/a694020.html)
Medlineplus source text (exact source wording)
Take venlafaxine exactly as directed. Do not take more or less of it or take it more often or for a longer period of time than prescribed by your doctor. Do not stop taking venlafaxine without talking to your doctor. Your doctor will probably decrease your dose gradually. you should know that this medication may make you drowsy and may affect your judgment, thinking, and movements. Do not drive a car or operate machinery until you know how this medication affects you. Take the tablet two or three times a day with food.
Label source text (exact source wording)
Prescribers or other health professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with venlafaxine tablets and should counsel them in its appropriate use. Patients should be advised to notify their physician if they develop a rash, hives, or a related allergic phenomenon.

Alternatives

Class per label and medlineplus
SNRI (selective serotonin and norepinephrine reuptake inhibitor) per MedlinePlus; 'structurally novel antidepressant' per label

Frequently asked questions

Question
What is venlafaxine used for?
Answer
The tablet label says it is indicated for the treatment of major depressive disorder. MedlinePlus also lists anxiety and panic disorders for venlafaxine products in general.
Source section
Indications and Usage
Source
DailyMed label (Avet); MedlinePlus
Question
Should I take venlafaxine with food?
Answer
Yes. The label says the tablets are taken with food, in two or three divided doses.
Source section
Dosage and Administration
Source
DailyMed label (Avet)
Question
What should I do if I miss a dose?
Answer
Take it as soon as you remember. If it is almost time for the next dose, skip the missed one. Do not take a double dose.
Source section
What should I do if I forget a dose?
Source
MedlinePlus
Question
Can I drink alcohol with venlafaxine?
Answer
The label advises patients to avoid alcohol while taking venlafaxine. MedlinePlus says alcohol can make the side effects worse.
Source section
Information for Patients: Alcohol
Source
DailyMed label (Avet); MedlinePlus
Question
What are the common side effects?
Answer
The label lists weakness, sweating, nausea, constipation, loss of appetite, vomiting, sleepiness, dry mouth, dizziness, nervousness, anxiety, tremor and blurred vision, plus abnormal ejaculation or orgasm and impotence in men, as the most commonly observed.
Source section
Adverse Reactions
Source
DailyMed label (Avet)
Question
Is venlafaxine safe in pregnancy or while breastfeeding?
Answer
There are no adequate and well-controlled studies in pregnant women, and it should be used in pregnancy only if clearly needed. Babies exposed late in the third trimester have had complications. Venlafaxine passes into breast milk, so you and your doctor should decide whether to stop nursing or the drug.
Source section
Pregnancy; Nursing Mothers
Source
DailyMed label (Avet)
Question
What should I not combine with venlafaxine?
Answer
Do not use it with MAOIs, linezolid or intravenous methylene blue as described in the label. Use caution with triptans, lithium, opioids, amphetamines, St. John's Wort, aspirin, NSAIDs and warfarin.
Source section
Contraindications; Drug Interactions
Source
DailyMed label (Avet)
Question
Should I stop venlafaxine when I feel better?
Answer
Do not stop without talking to your doctor. Stopping suddenly or lowering the dose quickly can cause new symptoms, and a gradual reduction is recommended whenever possible.
Source section
Discontinuation of Treatment; MedlinePlus How should this medicine be used?
Source
DailyMed label (Avet); MedlinePlus

Sources

Information is taken from the cited sources and is for general reference only. It is not medical advice. Report side effects to FDA MedWatch at 1-800-FDA-1088. For a poison emergency call 1-800-222-1222. See prices for this drug