Effexor Side Effects
Generic name: venlafaxine
Medically reviewed by Drugs.com. Last updated on Sep 25, 2023.
Note: This document contains side effect information about venlafaxine. Some dosage forms listed on this page may not apply to the brand name Effexor.
Applies to venlafaxine: oral capsule extended release, oral tablet, oral tablet extended release.
Warning
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
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More about Effexor (venlafaxine)
- Check interactions
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- Generic availability
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- Drug class: serotonin-norepinephrine reuptake inhibitors
- Breastfeeding
Professional resources
Other formulations
Related treatment guides
References
1. Product Information. Effexor (venlafaxine). Wyeth-Ayerst Laboratories. 2001.
2. Product Information. Effexor XR (venlafaxine). Wyeth-Ayerst Laboratories. 2002.
3. Cerner Multum, Inc. UK Summary of Product Characteristics.
4. Cerner Multum, Inc. Australian Product Information.
Further information
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.