Note: This document contains side effect information about bupropion. Some dosage forms listed on this page may not apply to the brand name Zyban.

Applies to bupropion: oral conventional tablets, oral extended-release tablets.

Side effects include:

Agitation, dry mouth, insomnia, headache/migraine, nausea/vomiting, constipation, tremor.

For Healthcare Professionals

Applies to bupropion: oral tablet, oral tablet extended release.

General

In placebo-controlled clinical studies, the specific adverse events that led to discontinuation in at least 1% of patients treated with either 300 mg or 400 mg per day of Wellbutrin SR (R)included rash, nausea, agitation, and migraine. Additional events leading to discontinuation in the immediate-release formulation included mental state abnormalities, vomiting, seizures, headaches, and sleep disturbances, many of which occurred at doses greater than the recommended daily dose.

Adverse events leading to treatment discontinuation with Zyban (R) included tremors, and rashes. The most commonly observed adverse reactions were dry mouth and insomnia. Smoking cessation is often associated with nicotine withdrawal symptoms, some of which are also recognized as adverse events associated with bupropion (the active ingredient contained in Zyban) ^[Ref]

Psychiatric

Very common (10% or more): Insomnia (up to 45%), agitation (up to 31.9%), abnormal dreams (up to 13%)

Common (1% to 10%): Anxiety, confusion, decreased/increased libido, decreased memory/memory impairment, delusions, depression, disturbed concentration, dysphoria, euphoria, hallucinations, hostility, impaired sleep quality, irritability, mania/hypomania, nervousness, thinking abnormality

Uncommon (0.1% to 1%): Aggression, bruxism, depersonalization, emotional lability, formal thought disorder, frigidity, mood instability, nightmares, paranoia, paranoid ideation, psychosis, suicidal ideation

Rare (0.01% to 0.1%): Derealization, impaired attention

Frequency not reported: Abnormalities in mental status, post-ictal confusion, sleep disturbances

Postmarketing reports: Completed suicide, delirium, manic reaction, restlessness, suicidal behavior, suicide attempt^[Ref]

The Australian Adverse Drug Reaction Advisory Committee reported that 285 of the 780 reports it received in association with bupropion through mid-May 2001 involved psychological disturbances.

Two cases of tactile hallucinations ("bugs crawling over skin") have been reported in association with bupropion extended-release (200 mg twice daily) therapy. In both cases the symptoms abated following a reduction in the total daily dose of bupropion (300 mg daily).

Insomnia may also be dose-dependent. In a dose response clinical study for smoking cessation, 29% of patients receiving bupropion 150 mg/day versus 35% of those receiving 300 mg/day reported insomnia. Insomnia may be minimized by reducing the dosage or avoiding administration at bedtime.^[Ref]

Nervous system

The Australian Adverse Drug Reaction Advisory Committee reported that 268 of the 780 reports it received in association with bupropion (the active ingredient contained in Zyban) through mid-May 2001 involved nervous system disorders.

Grand mal seizures have been reported in 0.4% of patients undergoing bupropion therapy at dosages up to 450 mg daily. The incidence of seizures increases dramatically at higher dosages. The seizure rate in patients taking sustained-release bupropion up to a dosage of 300 mg/day (e.g. for smoking cessation) has been approximated at 0.1%.

The risk of seizure appears to be dose-related. Other risk factors are related to patient factors e.g., severe head injury, arteriovenous malformation, CNS tumor or CNS infection, or severe stroke, concomitant medications that lower the seizure threshold (e.g., other bupropion products, antipsychotics, tricyclic antidepressants, theophylline, and systemic corticosteroids), metabolic disorders, illicit drug use, abuse or misuse of prescription drugs such as CNS stimulants, diabetes mellitus treated with oral hypoglycemics or insulin, treatment with anorectic drugs, and excessive use of alcohol, benzodiazepines, sedative/hypnotics, or opiates.

Two cases of elderly patients falling backwards have been attributed to the effects of bupropion on the basal ganglia.^[Ref]

Very common (10% or more): Headache (up to 34%), migraine (up to 25.7%), dizziness (up to 22.3%), tremor (up to 21.1%), sedation (up to 19.8%)

Common (1% to 10%): Akathisia, ataxia/incoordination, central nervous system stimulation, dyskinesia, dystonia, feeling jittery, myoclonus, paresthesia, seizure, sensory disturbance, somnolence, syncope, taste disturbance, taste perversion

Uncommon (0.1% to 1%): Abnormal coordination, dysarthria, hypesthesia, hyperkinesia, hypertonia, vertigo

Rare (0.01% to 0.1%): Abnormal electroencephalogram, amnesia, parkinsonism

Frequency not reported: Generalized tonic-clonic seizures

Postmarketing reports: Akinesia, aphasia, coma, extrapyramidal syndrome, hypokinesia, neuropathy, neuralgia, unmasking tardive dyskinesia^[Ref]

Metabolic

Very common (10% or more): Weight loss greater than 2.3 kg (up to 28%), weight gain greater than 2.3 kg (up to 11%)

Common (1% to 10%): Anorexia, decreased appetite, increased appetite, thirst/thirst disturbance

Rare (0.01% to 0.1%): Blood glucose disturbances

Very rare (less than 0.01%): Hyponatremia

Postmarketing reports: Hyperglycemia, hypoglycemia^[Ref]

Gastrointestinal

Very common (10% or more): Dry mouth (up to 27.6%), constipation (up to 26%), nausea (up to 22.9%), vomiting (up to 22.9%)

Common (1% to 10%): Abdominal pain, diarrhea, dyspepsia, dysphagia, flatulence, gastrointestinal disturbance, gustatory disturbance, mouth ulcer, stomatitis

Uncommon (0.1% to 1%): Gastric reflux, gingivitis, gum irritation, increased salivation, inguinal hernia, oral edema, toothache

Rare (0.01% to 0.1%): Edema of the tongue, intestinal perforation

Frequency not reported: Esophagitis

Postmarketing reports: Colitis, gastrointestinal hemorrhage, glossitis, gum hemorrhage, pancreatitis, stomach ulcer, stool abnormality^[Ref]

Dermatologic

The Australian Adverse Drug Reaction Advisory Committee reported that 307 of the 780 reports it received in association with bupropion (the active ingredient contained in Zyban) through mid- May 2001 involved skin reactions. Urticaria was the most commonly reported event (167 cases). Other rashes (86 cases) were also reported.^[Ref]

Very Common (10% or more): Excessive sweating (up to 22.3%)

Common (1% to 10%): Dry skin, facial edema, pruritus, rash, sweating, urticaria

Uncommon (0.1% to 1%): Alopecia, ecchymosis, photosensitivity

Rare (0.01% to 0.1%): Erythema multiforme, exacerbation of psoriasis, Stevens-Johnson syndrome

Frequency not reported: Skin reactions

Postmarketing reports: Exfoliative dermatitis, hirsutism, maculopapular rash^[Ref]

Local

Very common (10% or more): Application site reaction (up to 15%)^[Ref]

Ocular

Very common (10% or more): Blurred vision (up to 14.6%)

Common (1% to 10%): Diplopia, visual disturbance

Uncommon (0.1% to 1%): Accommodation abnormality, dry eye, mydriasis

Postmarketing reports: Angle-closure glaucoma, increased intraocular pressure^[Ref]

Respiratory

Very common (10% or more): Nasopharyngitis (up to 13%), rhinitis (up to 12%), pharyngitis (up to 11%)

Common (1% to 10%): Bronchitis, cough, dyspnea/shortness of breath, epistaxis, increased cough, sinusitis, upper respiratory tract infection

Rare (0.01% to 0.1%): Bronchospasm, pulmonary embolism

Postmarketing reports: Pneumonia^[Ref]

Cardiovascular

In clinical practice, hypertension, in some cases severe, requiring acute treatment, has been reported in patients receiving bupropion (the active ingredient contained in Zyban) alone and in combination with nicotine replacement therapy. These events have been observed in both patients with and without evidence of preexisting hypertension.

Some investigators have suggested that bupropion therapy may be 10 to 100 times less likely to induce conduction problems than tricyclic antidepressants.^[Ref]

Very Common (10% or more): Tachycardia (up to 11%)

Common (1% to 10%): Cardiac arrhythmias, chest pain, edema, flushing, hot flashes, hypertension, hypotension, palpitations

Uncommon (0.1% to 1%): Electrocardiogram abnormalities, nonspecific ST-T changes, peripheral edema, postural hypotension, premature beats, stroke, vasodilation

Rare (0.01% to 0.1%): Myocardial infarction

Postmarketing reports: Cardiovascular disorder, complete atrioventricular block, extrasystoles, orthostatic hypotension, phlebitis, severe hypertension, third degree heart block^[Ref]

Other

Common (1% to 10%): Accidental injury, asthenia, auditory disturbance, chills, cutaneous temperature disturbance, fever, nonspecific fever, pain, temperature disturbance, tinnitus

Uncommon (0.1% to 1%): Inguinal hernia, nonspecific pain

Rare (0.01% to 0.1%): Malaise, overdose

Postmarketing reports: Deafness^[Ref]

Genitourinary

Common (1% to 10%): Decrease in sexual function, dysmenorrhea, impotence, menstrual complaints, nocturia, urinary frequency, urinary tract infection, urinary urgency, vaginal hemorrhage

Uncommon (0.1% to 1%): Painful erection, polyuria, prostate disorder, retarded ejaculation, testicular swelling, vaginal irritation

Rare (0.01% to 0.1%): Enuresis, urinary incontinence, urinary retention

Postmarketing reports: Abnormal ejaculation, dyspareunia, dysuria, menopause, prostate disorder, salpingitis, urinary tract disorder, vaginitis^[Ref]

One study in which 150 patients received the sustained released form of bupropion reported the incidence of orgasm dysfunction at 8% in patients receiving a 300 mg daily dose and 10% in patients receiving a 400 mg daily dose.

Among antidepressants, bupropion may be associated with the lowest incidence of sexual dysfunction (i.e., impotence, abnormal ejaculation, changes in libido).^[Ref]

Musculoskeletal

Common (1% to 10%): Arthralgia, arthritis, myalgia, neck pain, pain in extremity, twitch/twitching

Uncommon (0.1% to 1%): Leg cramps

Postmarketing reports: Muscle rigidity, muscle weakness, musculoskeletal chest pain, rhabdomyolysis^[Ref]

Hypersensitivity

Common (1% to 10%): Allergic reaction, hypersensitivity reactions

Uncommon (0.1% to 1%): Fever with rash and other symptoms suggestive of delayed hypersensitivity

Rare (0.01% to 0.1%): Angioedema, anaphylactic shock^[Ref]

Immunologic

Common (1% to 10%): Flu-like symptoms, infection

Uncommon (0.1% to 1%): Serum sickness-like reaction^[Ref]

Hepatic

Uncommon (0.1% to 1%): Abnormal liver function, jaundice, liver damage

Rare (0.01% to 0.1%): Elevated liver enzymes, hepatitis^[Ref]

Endocrine

Uncommon (0.1% to 1%): Gynecomastia

Frequency not reported: Syndrome of inappropriate antidiuretic hormone^[Ref]

Renal

Rare (0.01% to 0.1%): Glycosuria

Postmarketing reports: Cystitis^[Ref]

Hematologic

Frequency not reported: Anemia, leukopenia, thrombocytopenia

Postmarketing reports: Altered prothrombin time/INR with/without hemorrhagic/thrombotic complications, leukocytosis, lymphadenopathy, pancytopenia^[Ref]