Drug reference

Amantadine

Dopamine Agonist · Antiparkinsonian

Also known as Amantadine hydrochloride

Dopamine AgonistAntiparkinsonianATC J05AG02

CDSCO approvedATC J05AG02

EXCRETION

—

not curated

INTERACTIONS

4 major

SEVERE in our sources

PREGNANCY

FDA category + note

Top interactionssee all 6 →

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Mechanism

Amantadine is a weak dopamine agonist with modest antiparkinsonian effects.

Indications

Parkinson’s diseasePost-herpetic neuralgiaTreatment of influenza A (not recommended)Fatigue in multiple sclerosis (off-label)Antipsychotic-induced parkinsonismInitial therapy for mild PDAdjunct in patients on levodopa with dose-related fluctuations and dyskinesiasProphylaxis and treatment of influenza Aprevention of influenza A virus infectionstreatment of influenza A virus infectionsseasonal prophylaxis against influenza A illnesspreventing nosocomial influenzacurtailing nosocomial outbreaks during pandemic influenzauncomplicated influenza A illnessParkinson's disease (milder cases, short courses to supplement levodopa for advanced cases to suppress motor fluctuations and abnormal movements)Prophylaxis of influenza A2Influenza A2 (prophylaxis during an epidemic)prophylaxis of influenza A2 during an epidemic or seasonal influenza (especially in high risk patients)treatment of influenzal (A2) illness (modest effect if given immediately after symptoms appear, 5 day treatment)Parkinsonism

Dosing

Adult: Parkinson’s disease: BY MOUTH 100 mg daily for 1 week, then increased to 100 mg twice daily; some patients may require higher doses. Post-herpetic neuralgia: BY MOUTH 100 mg twice daily for 14 days (continued for another 14 days if necessary). Fatigue in multiple sclerosis: BY MOUTH 100 mg daily for 1 week, dose to be taken in the morning, then increased to 100 mg twice daily.
Pediatric: 5 mg/kg per day, up to 150 mg, once or twice daily (children ≥1 year)
Renal adjustment: Creatinine clearance of 30–50 mL/min: 200 mg given once followed by 100 mg every 24 h.
Geriatric: 100 mg daily, adjusted according to response.
Max dose: 400 mg per day

Pharmacokinetics

Peak effect

1–4 h

Half-life

12–18 h (healthy young adults), longer with renal impairment.

Protein binding

67%

Metabolism

<10% metabolized

Excretion

Renal (more than 90% recovered unmetabolized in the urine)

Contraindications

Epilepsy
History of gastric ulceration
other CNS disease
gastric ulcer
pregnancy

Side effects

Common

AnxietyAppetite decreasedConcentration impairedConfusionConstipationDepressionDizzinessDry mouthHallucinationHeadacheHyperhidrosisLethargyMood alteredMovement disordersMyalgiaNauseaPalpitationsanticholinergic effectssleep disturbancevomitingnervousnesslight-headednessdifficulty concentratinginsomnialoss of appetiterestlessnessnightmareslivedo reticularis (bluish discolouration)edema of anklesanorexialack of mental concentrationankle edema (due to local vasoconstriction)

Serious