Formulary
Amantadine hydrochloride: Indications, Dosing, Side Effects and Interactions
Amantadine is a weak dopamine agonist with modest antiparkinsonian effects.
MedNext Academy | 3 min read
Amantadine hydrochloride: Indications, Dosing, Side Effects and Interactions
Amantadine is a weak dopamine agonist with modest antiparkinsonian effects.
Drug action
Amantadine is a weak dopamine agonist with modest antiparkinsonian effects.
Indications and dose
**Parkinson's disease**
- **Adult** (By Mouth): 100 mg daily for 1 week, then increased to 100 mg twice daily, usually administered in conjunction with other treatment. Some patients may require higher doses; maximum 400 mg per day.
- **Elderly** (By Mouth): 100 mg daily, adjusted according to response.
**Post-herpetic neuralgia**
- **Adult** (By Mouth): 100 mg twice daily for 14 days (continued for another 14 days if necessary).
**Treatment of influenza A (but not recommended)**
- **Adult** (By Mouth): 100 mg daily 4-5 days.
**Prophylaxis of influenza A (but not recommended)**
- **Adult** (By Mouth): 100 mg daily usually for 6 weeks or with influenza vaccination for 2-3 weeks after vaccination.
**Fatigue in multiple sclerosis (initiated by a specialist)**
- **Adult** (By Mouth): 100 mg daily for 1 week, dose to be taken in the morning, then increased to 100 mg twice daily; maximum 400 mg per day.
Cautions
Confused or hallucinatory states; congestive heart disease (may exacerbate oedema); elderly; tolerance to the effects of amantadine may develop in Parkinson's disease
Contraindications
Epilepsy; history of gastric ulceration
Side effects
Common or very common Anxiety; appetite decreased; concentration impaired; confusion; constipation; depression; dizziness; dry mouth; hallucination; headache; hyperhidrosis; lethargy; mood altered; movement disorders; myalgia; nausea; palpitations; peripheral oedema; postural hypotension; skin reactions; sleep disorders; speech slurred; vision disorders; vomiting Uncommon Psychosis; seizure; tremor Rare or very rare Cardiovascular insufficiency; diarrhoea; eye disorders; eye inflammation; heart failure; leucopenia; neuroleptic malignant syndrome; photosensitivity reaction; urinary disorders Frequency not known Delirium
Interactions
**Other interactions (5):**
- Special precautions Concurrent administration of amantadine and anticholinergic agents or levodopa may increase confusion, hallucinations, nightmares, gastro-intestinal disturbances, or other...
- Psychotic reactions have been observed in patients receiving amantadine and levodopa.
- Concurrent administration of amantadine and drugs or substances (e.g.
- Concurrent administration with alcohol may aggravate the signs and symptoms of acute poisoning with amantadine.
- There have been isolated reports of a suspected interaction between amantadine and combination diuretics (hydrochlorothiazide + potassium sparing diuretics).
Pregnancy
Avoid; toxicity in animal studies.
Breast feeding
Avoid; present in milk; toxicity in infant reported.
Hepatic impairment
Manufacturer advises use with caution in liver disorders.
Renal impairment
Avoid if creatinine clearance less than 15 mL/minute. M See Prescribing in renal impairment . Dose adjustments Reduce dose (consult product literature). M
Medicinal forms
Tablet,Capsule,Solution
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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