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