Applies to amantadine: oral conventional capsules, oral conventional tablets, oral extended-release tablets, oral extended-release capsules, oral oral solution.

Side effects include:

Nausea, dizziness (lightheadedness), insomnia.

For Healthcare Professionals

Applies to amantadine: compounding powder, oral capsule, oral capsule extended release, oral syrup, oral tablet, oral tablet extended release.

General

The more commonly reported adverse reactions have included nausea, dizziness/lightheadedness, and insomnia.^[Ref]

Nervous system

Common (1% to 10%): Dizziness/lightheadedness, ataxia, headache, somnolence, dystonia

Uncommon (0.1% to 1%): Weakness, slurred speech, hyperkinesia

Rare (less than 0.1%): Convulsion

Frequency not reported: Falling asleep during activities of daily living, withdrawal-emergent hyperpyrexia (a syndrome resembling neuroleptic malignant syndrome)

Postmarketing reports: Coma, delirium, hypokinesia, involuntary muscle contractions, gait abnormalities, paresthesia, EEG changes, tremor^[Ref]

Psychiatric

Very common (10% or more): Hallucinations (up to 21%)

Common (1% to 10%): Insomnia, depression, anxiety, irritability, hallucinations, confusion, nervousness, abnormal dreams, agitation

Uncommon (0.1% to 1%): Psychosis, euphoria, abnormal thinking, amnesia

Rare (less than 0.1%): Suicide attempt, suicide, suicidal ideation

Postmarketing reports: Stupor, delusions, aggressive behavior, paranoid reaction, manic reaction, pathological gambling, increased libido including hypersexuality, and impulse control symptoms^[Ref]

Gastrointestinal

Very common (10% or more): Dry mouth (up to 16%); constipation (up to 13%)

Common (1% to 10%): Nausea, anorexia, diarrhea, decreased appetite

Uncommon (0.1% to 1%): Vomiting

Postmarketing reports: Dysphagia^[Ref]

Cardiovascular

Very common (10% or more): Peripheral edema (up to 16%), orthostatic hypotension (up to 13%)

Uncommon (0.1% to 1%): Congestive heart failure, hypertension

Postmarketing reports: Cardiac arrest, arrhythmias including malignant arrhythmias, hypotension, and tachycardia^[Ref]

Ocular

Common (1% to 10%): Dry eye, cataract, blurred vision

Uncommon (0.1% to 1%): Visual disturbance, punctate subeithelial or other corneal opacity, corneal edema, decreased visual acuity, sensitivity to light, optic nerve palsy

Rare (less than 0.1%): Oculogyric episodes

Postmarketing reports: Keratitis, mydriasis^[Ref]

Other

Very common (10% or more): Fall (up to 13%)

Common (1% to 10%): Fatigue, contusions

Frequency not reported: Death

Postmarketing reports: Fever^[Ref]

Deaths have been reported from overdose with the lowest reported acute lethal dose as 1 gram. Drug overdose has resulted in cardiac, respiratory, renal, or CNS toxicity. Deaths have been reported in patients with renal impairment and attributed to drug accumulation.^[Ref]

Respiratory

Common (1% to 10%): Dry nose, cough

Uncommon (0.1% to 1%): Dyspnea

Postmarketing reports: Acute respiratory failure, pulmonary edema, tachypnea^[Ref]

Hematologic

Rare (less than 0.1%): Leukopenia, neutropenia

Postmarketing reports: Leukocytosis, agranulocytosis^[Ref]

Dermatologic

Common (1% to 10%): Livedo reticularis, pigmentation disorder

Uncommon (0.1% to 1%): Skin rash

Rare (less than 0.1%): Eczematoid dermatitis

Postmarketing reports: Pruritus, diaphoresis^[Ref]

Hypersensitivity

Postmarketing reports: Allergic reactions including anaphylactic reactions^[Ref]

Genitourinary

Common (1% to 10%): Urinary tract infection, benign prostatic hyperplasia

Uncommon (0.1% to 1%): Urinary retention, decreased libido^[Ref]

Renal

Postmarketing reports: Elevated: CPK, BUN, serum creatinine^[Ref]

Hepatic

Rare (less than 0.1%): Reversible liver enzyme elevations

Postmarketing reports: Elevated: alkaline phosphatase, LDH, bilirubin, GGT, SGOT, and SGPT^[Ref]

Musculoskeletal

Common (1% to 10%): Joint swelling, muscle spasms^[Ref]