Amantril is indicated for- Treatment of parkinsonism Treatment of drug-induced extrapyramidal reactions Prophylaxis and treatment of signs and symptoms of infection caused by various strains of influenza A virus
Amantadine Hydrochloride has direct and indirect effects on dopamine neurons. It acts on the pre-synaptic membrane, enhancing the release of dopamine and inhibiting its reuptake. Post-synaptically, Amantadine acts directly on the dopamine receptor, and up regulates D2 receptors. This may be due to Amantadine-induced hypersensitivity of dopamine receptors. It has antimuscarinic properties. Amantadine also has antiglutamatergic properties, via non-competitive antagonism of NMDA receptors. Furthermore, potent, competitive, non-subunit selective NMDA receptor antagonists reduce the severity of levodopa-induced dyskinesias. NMDA receptor sensitization may be a key event in the genesis of levodopa-induced dyskinesias. It also has immunomodulatory properties. It restores the production of interleukin-2 (IL-2), which is defective in Parkinson’s disease patients. The mechanism by which Amantadine exerts its antiviral activity is not clearly understood. It appears to mainly prevent the release of infectious viral nucleic acid into the host cell by interfering with the function of the transmembrane domain of the viral M2 protein. Amantadine is also known to prevent virus assembly during virus replication. It does not appear to interfere with the immunogenicity of inactivated influenza A virus vaccine.
Always consult a registered doctor before taking any medicine. This information is for general knowledge only.
Adults: 200 mg/day as single dose or 100 mg twice daily. If CNS effects develop on a once- daily dosage, split dosage schedule may reduce complaints. Elderly over 65 years of age: 100 mg every day. Children: 1 to 9 years of age: 4.4 to 8.8 mg/kg/day; not to exceed 150 mg/day. 9 to 12 years of age: 100 mg twice daily Method of administration : Each capsule is to be taken orally either with or without food. Patients with renal impairment : The dose should be reduced. This can be achieved by either reducing the total daily dose, or by increasing the dosage interval in accordance with the creatinine clearance. Patients with hepatic impairment : Use with caution.
The adverse effects of Amantril are generally mild and, when they occur, may diminish or cease after a week or more on the medication. The most commonly reported side effects include nausea, dizziness/lightheadedness, and insomnia. Other side effects may include edema of ankles, livedo reticularis; anxiety, elevation of mood, headache, lethargy, hallucinations, ataxia, slurred speech, blurred vision, loss of concentration, nervousness, depression, myalgia, palpitations, orthostatic hypotension, dry mouth, anorexia, constipation and diaphoresis.
Amantadine is contraindicated in patients with known hypersensitivity to the active substances or to any of the excipients.
Concurrent administration of Amantril and anticholinergic agents or levodopa may increase confusion, hallucinations, nightmares, gastro-intestinal disturbances, or other atropine-like side effects. Psychotic reactions have been observed in patients receiving Amantril and Levodopa. Concurrent administration of Amantril and drugs or substances (e.g. alcohol) acting on the CNS may result in additive CNS toxicity. Close observation is recommended.
Amantril should not be discontinued abruptly in patients with Parkinson's disease since a few patients have experienced a parkinsonian crisis, i.e., a sudden marked clinical deterioration, when this medication was suddenly stopped. The dose of anticholinergic drugs or of Amantril should be reduced if atropine-like effects appear when these drugs are used concurrently. Abrupt discontinuation may also precipitate delirium, agitation, delusions, hallucinations, paranoid reaction, stupor, anxiety, depression and slurred speech.