Effexor Side Effects

Generic name: venlafaxine

Medically reviewed by Drugs.com. Last updated on Sep 25, 2023.

Note: This document provides detailed information about Effexor Side Effects associated with venlafaxine. Some dosage forms listed on this page may not apply specifically to the brand name Effexor.

Applies to venlafaxine: oral capsule extended release, oral tablet, oral tablet extended release.

Important warnings This medicine can cause some serious health issues

Oral route (capsule, extended release)

Antidepressants increased the risk of suicidal thoughts and behavior in pediatric and young adult patients in short-term studies.

Closely monitor all antidepressant-treated patients for clinical worsening, and emergence of suicidal thoughts and behaviors.

Venlafaxine hydrochloride is not approved for use in pediatric patients.

Oral route (tablet; tablet, extended release)

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 is not approved for use in pediatric patients

Serious side effects of Effexor

Along with its needed effects, venlafaxine (the active ingredient contained in Effexor) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking venlafaxine:

More common

• change or problem with discharge of semen
• decreased interest in sexual intercourse
• inability to have or keep an erection
• lack or loss of strength
• loss in sexual ability, desire, drive, or performance
• severe headache
• sweating

Less common

• blurred vision
• chest pain
• delayed or inability to have an orgasm
• fast or irregular heartbeat
• mood or mental changes
• ringing or buzzing in the ears
• suicidal thoughts

Rare

• actions that are out of control
• high fever
• irritability
• itching or skin rash
• lightheadedness or fainting, especially when getting up suddenly from a sitting or lying position
• menstrual changes
• nervousness
• problems with urinating or holding urine
• seizures
• severe muscle stiffness
• talking, feeling, and acting with excitement that you cannot control
• trouble breathing
• unusually pale skin

Incidence not known

• agitation
• bloody, black, or tarry stools
• bloody stool or urine
• dark urine
• decreased frequency or amount of urine
• diarrhea
• drowsiness
• fever
• general feeling of tiredness or weakness
• headache
• increased thirst
• light-colored stools
• muscle cramps, spasms, or pain
• nausea or vomiting
• nosebleeds
• overactive reflexes
• poor coordination
• red or purple spots on the skin
• restlessness
• shivering
• stomach pain on the upper right side
• swelling of the face, lower legs, ankles, hands, or fingers
• trembling or shaking that is hard to control
• twitching
• unusual bruising
• unusual tiredness or weakness
• vomiting of blood or material that looks like coffee grounds
• yellow eyes or skin

Other side effects of Effexor

Some side effects of venlafaxine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• abnormal dreams
• chills
• constipation
• decrease in sexual desire or ability
• diarrhea
• dry mouth
• heartburn
• increased sweating
• loss of appetite
• nausea
• stomach pain or gas
• stuffy or runny nose
• tingling, burning, or prickly sensations
• trouble sleeping
• vomiting
• weight loss

Less common

• change in taste
• muscle tension
• yawning

Incidence not known

• decrease in smell
• loss of sense of smell
• night sweats

For healthcare professionals

Applies to venlafaxine: oral capsule extended release, oral tablet, oral tablet extended release.

General

The most commonly reported side effects were nausea, headache, somnolence, and dizziness.^[Ref]

Gastrointestinal

• Very common (10% or more): Nausea (up to 58%), dry mouth (up to 22%), constipation (up to 15%)
• Common (1% to 10%): Abdominal pain, diarrhea, dyspepsia, eructation, flatulence, vomiting
• Uncommon (0.1% to 1%): Circumoral paresthesia, colitis, dysphagia, esophagitis, gastritis, gastroenteritis, gastrointestinal hemorrhage, gastrointestinal ulcer, gingivitis, glossitis, hemorrhoids, melena, mouth ulceration, oral moniliasis, rectal hemorrhage, stomatitis, tongue edema
• Rare (less than 0.1%): Abdominal distention, buccoglossal syndrome, cheilitis, cholecystitis, cholelithiasis, duodenitis, esophageal spasm, gastroesophageal reflux disease, gum hemorrhage, hematemesis, hyperchlorhydria, ileitis, increased salivation, intestinal obstruction, pancreatitis, parotitis, periodontitis, proctitis, salivary gland enlargement, soft stools, tongue discoloration^[Ref]

Nervous system

• Very common (10% or more): Headache (up to 38%), somnolence (up to 26.1%), dizziness (up to 23.9%), tremor (up to 10.2%)
• Common (1% to 10%): Akathisia, amnesia, dysgeusia, hypertonia, hypesthesia, increased muscle tone, migraine, paresthesia, sedation, taste perversion, vertigo
• Uncommon (0.1% to 1%): Abnormal coordination, abnormal speech, ataxia, balance disorder, central nervous system (CNS) stimulation, dyskinesia, hyperesthesia, hyperkinesia, hypotonia, incoordination, myoclonus, neuralgia, neuropathy, parosmia, seizure, syncope, stupor, taste loss, visual field defect
• Rare (0.1% to 0.01%): Abnormal gait, akinesia, aphasia, bradykinesia, cerebral ischemia, cerebrovascular accident, convulsion, dementia, dystonia, facial paralysis, Guillain-Barre Syndrome, hypokinesia, loss of consciousness, neuritis, neuroleptic malignant syndrome (NMS), nystagmus, paresis, reflexes decreased, reflexes increased, serotonin syndrome, torticollis
• Very rare (less than 0.01%): Extrapyramidal reactions, tardive dyskinesia
• Frequency not reported: Impaired coordination, sensory disturbance
• Postmarketing reports: Coordination abnormal, impaired balance, involuntary movements, NMS-like reactions, shock-like electrical sensations^[Ref]

Psychiatric

• Very common (10% or more): Insomnia (up to 24%), nervousness (up to 21.3%), abnormal orgasm (up to 12.5%), anxiety (up to 11.2%)
• Common (1% to 10%): Abnormal dreams, abnormal thinking, agitation, anorgasmia, confusion, depersonalization, depression, libido decreased, orgasm disturbance, orgasmic dysfunction
• Uncommon (0.1% to 1%): Apathy, bruxism, derealization, emotional lability, euphoria, hallucination, hostility, hypomania, libido increased, mania, manic reaction, psychosis, suicidal ideation, suicide attempt, withdrawal syndrome
• Rare (less than 0.1%): Alcohol abuse, delirium, delusions, homicidal ideation, hysteria, impulse control difficulties, paranoid reaction, psychotic depression, psychomotor restlessness
• Frequency not reported: Aggression, delayed orgasm, increased dreaming, intense dreams, nightmares, other sleep disorders, self-harm, sleep disturbances, suicidal behaviors, vivid dreams, withdrawal symptoms
• Postmarketing reports: Catatonia, confusional state, panic, paranoia, psychotic disorder^[Ref]

Dermatologic

• Very common (10% or more): Sweating (up to 19.3%), night sweats (up to 11.4%)
• Common (1% to 10%): Ecchymosis, hyperhidrosis, pruritus, rash
• Uncommon (0.1% to 1%): Acne, alopecia, brittle nails, contact dermatitis, dry skin, eczema, face edema, maculopapular rash, photosensitivity reaction, psoriasis, skin hypertrophy, urticaria
• Rare (less than 0.1%): Cellulitis, erythema multiforme, erythema nodosum, exfoliative dermatitis, furunculosis, granuloma, hair discoloration, hirsutism, leukoderma, lichenoid dermatitis, miliaria, mucocutaneous hemorrhage, petechial rash, pruritic rash, purpura, pustular rash, seborrhea, skin atrophy, skin discoloration, skin striae, Stevens-Johnson syndrome, sweating decreased, toxic epidermal necrolysis, vesiculobullous rash^[Ref]

Metabolic

• Very common (10% or more): Anorexia (up to 20%)
• Common (1% to 10%): Blood cholesterol increased, decreased appetite, increased appetite, weight gain, weight loss
• Uncommon (0.1% to 1%): Dehydration, hyperglycemia, hyperlipemia, hyperlipidemia, hypokalemia, hyponatremia, increased alkaline phosphatase, thirst
• Rare (less than 0.1%): Alcohol intolerance, diabetes mellitus, gout, hemochromatosis, hypercholesteremia, hyperkalemia, hyperphosphatemia, hyperuricemia, hypocholesteremia, hypoglycemia, hypophosphatemia, hypoproteinemia
• Frequency not reported: Height changes, loss of appetite, weight changes
• Postmarketing reports: Lactate dehydrogenase (LDH) increased^[Ref]

Other

• Very common (10% or more): Asthenia (up to 19%)
• Common (1% to 10%): Accidental injury, chills, fatigue, fever, tinnitus, trauma
• Uncommon (0.1% to 1%): Hyperacusis, intentional injury, malaise, otitis media
• Rare (less than 0.1%): Abortion, deafness, energy increased, feeling drunk, healing abnormal, labyrinthitis, menopause, motion sickness, otitis externa
• Frequency not reported: Discontinuation syndrome, pain
• Postmarketing reports: Congenital anomalies^[Ref]

Genitourinary

• Very common (10% or more): Abnormal ejaculation (up to 16%)
• Common (1% to 10%): Albuminuria, enlarged prostate, erectile dysfunction, impotence, metrorrhagia, pollakiuria, prostatic disorder, prostatitis, urinary frequency, urinary hesitation, urinary retention, urination impaired, vaginitis
• Uncommon (0.1% to 1%): Amenorrhea, bladder pain, breast pain, cystitis, dysuria, hematuria, leukorrhea, menorrhagia, nocturia, pelvic pain, polyuria, prostate irritability, pyuria, urinary incontinence, urinary urgency, vaginal hemorrhage
• Rare (less than 0.1%): Balanitis, breast discharge, breast engorgement, breast enlargement, calcium crystalluria, cervicitis, endometriosis, galactorrhea, hypercalcinuria, hypomenorrhea, lactation (female), mastitis, menstrual disorders associated with increased bleeding or increased irregular bleeding, ovarian cyst, orchitis, prolonged erection, salpingitis, urolithiasis, uterine hemorrhage, uterine spasm, vaginal dryness
• Frequency not reported: Delayed ejaculation, dysmenorrhea
• Postmarketing reports: Proteinuria^[Ref]

Cardiovascular

• Common (1% to 10%): Chest pain, edema, hot flashes/hot flush, hypertension/increased blood pressure, palpitation, postural hypotension, substernal chest pain, tachycardia, vasodilation
• Uncommon (0.1% to 1%): Angina pectoris, arrhythmia, bradycardia, cold feet, cold hands, extrasystoles, hypotension, orthostatic hypotension, peripheral vascular disorder, thrombophlebitis
• Rare (less than 0.1%): Aortic aneurysm, arteritis, bigeminy, bundle branch block, capillary fragility, cardiovascular disorder (mitral valve and circulatory disturbance), coronary artery disease, congestive heart failure, cyanosis, ECG QT prolonged, first-degree atrioventricular block, heart arrest, hematoma, myocardial infarct, pallor, sinus arrhythmia, torsade de pointes, ventricular fibrillation, ventricular tachycardia
• Postmarketing reports: Atrial fibrillation, deep vein thrombophlebitis, ECG abnormalities, stress cardiomyopathy, supraventricular tachycardia, Takotsubo cardiomyopathy, ventricular extrasystole^[Ref]

Respiratory

• Common (1% to 10%): Bronchitis, cough increased, dyspnea, pharyngitis, sinusitis, yawn/yawning
• Uncommon (0.1% to 1%): Asthma, chest congestion, epistaxis, hyperventilation, laryngismus, laryngitis, pneumonia, voice alteration
• Rare (less than 0.1%): Atelectasis, hemoptysis, hypoventilation, hypoxia, interstitial lung disease, larynx edema, pleurisy, pulmonary embolus, pulmonary eosinophilia, sleep apnea
• Frequency not reported: Rhinitis, upper respiratory infection, upper respiratory tract infection^[Ref]

Ocular

• Common (1% to 10%): Abnormality of accommodation, abnormal vision, blurred vision, mydriasis
• Uncommon (0.1% to 1%): Cataract, conjunctivitis, corneal lesion, diplopia, dry eyes, eye pain, photophobia
• Rare (less than 0.1%): Angle-closure glaucoma, blepharitis, chromatopsia, conjunctival edema, decreased pupillary reflex, exophthalmos, eye hemorrhage, keratitis, miosis, papilledema, retinal hemorrhage, scleritis, subconjunctival hemorrhage, uveitis
• Frequency not reported: Difficulty focusing eyes^[Ref]

Musculoskeletal

• Common (1% to 10%): Neck pain, trismus, twitching
• Uncommon (0.1% to 1%): arthritis, arthrosis, bone pain, bone spurs, bursitis, leg cramps, myasthenia, neck rigidity, tenosynovitis
• Rare (less than 0.1%): Muscle cramp, muscle spasms, musculoskeletal stiffness, myopathy, osteoporosis, osteosclerosis, pathological fracture, plantar fasciitis, rhabdomyolysis, rheumatoid arthritis, tendon rupture
• Frequency not reported: Arthralgia, back pain, myalgia
• Postmarketing reports: Bone fracture, creatine phosphokinase (CPK) increased^[Ref]

Immunologic

• Common (1% to 10%): Flu syndrome, infection
• Uncommon (0.1% to 1%): Moniliasis
• Rare (less than 0.1%): Appendicitis, bacteremia^[Ref]

Hematologic

• Uncommon (0.1% to 1%): Anemia, leukocytosis, leukopenia, lymphadenopathy, mucous membrane bleeding, mucosal hemorrhage, thrombocythemia, thrombocytopenia
• Rare (less than 0.1%): Agranulocytosis, aplastic anemia, basophilia, blood dyscrasias, eosinophilia, lymphocytosis, neutropenia, pancytopenia, prolonged bleeding time
• Postmarketing reports: INR increased, prolonged partial thromboplastin time, prothrombin time increased^[Ref]

Hepatic

• Uncommon (0.1% to 1%): Abnormal liver function tests, ALT increased, AST increased
• Rare (less than 0.1%): Biliary pain, bilirubinemia, cholecystitis, cholelithiasis, hepatitis, jaundice, liver tenderness
• Postmarketing reports: Fatty liver, GGT elevation, hepatic reactions, liver damage, liver failure, liver necrosis^[Ref]

Renal

• Uncommon (0.1% to 1%): Kidney calculus, kidney pain
• Rare (less than 0.1%): Anuria, blood urea nitrogen (BUN) increased, creatinine increased, glycosuria, kidney function abnormal, oliguria, pyelonephritis, uremia
• Postmarketing reports: Renal failure^[Ref]

Hypersensitivity

• Uncommon (0.1% to 1%): Angioedema
• Rare (less than 0.1%): Anaphylactic reaction, anaphylaxis
• Frequency not reported: Hypersensitivity^[Ref]

Endocrine

• Rare (0.1% to 0.01%): Goiter, gynecomastia (male), hyperthyroidism, hypothyroidism, inappropriate antidiuretic hormone secretion (SIADH)/syndrome of inappropriate antidiuretic hormone secretion, thyroid nodule, thyroiditis
• Very rare (less than 0.01%): Blood prolactin increased^[Ref]

Oncologic

• Rare (less than 0.1%): Carcinoma, fibrocystic breast, multiple myeloma^[Ref]

Frequently asked questions

• How long do venlafaxine withdrawal symptoms last?
• SSRIs vs SNRIs - What's the difference between them?

Further information

Effexor side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer