Amantadine
Antiparkinsonism Preps · Tricyclic amine
Indications
Parkinsonism. Protection or treatment for patients with A2 or A/New Jersey influenza in whom complications might be expected or who are at risk. Herpes zoster.
Dosage
Parkinsonism: Adults: 100 mg daily for first wk increasing to 100 mg twice daily. Children: Not recommended. Influenza: Adults: Treatment: 100 mg twice daily for 5-7 days. Prophylaxis: 100 mg twice daily for 7-10 days. Children: Under 10 yr, not recommended; over 10 yr, treatment and prophylaxis, 100 mg every morning. Herpes zoster: Adults: 100 mg twice daily for 14- 28 days. Children: Not recommended.
Adverse Effects
Livedo reticularis, peripheral oedema. Skin rash, visual, CNS & GI disturbances, headache, blurred vision, anorexia, dry mouth, sweating, palpitations, orthostatic hypotension, myalgia, fatigue.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Risk cannot be ruled out. Lactation: Contraindicated or not recommended. Contraindications: History of convulsions or gastric ulceration. Severe renal disease. Untreated closed-angle glaucoma. Precautions: Liver disease, congestive heart failure, history of cardiovascular disorders. Confusion, hallucinations, other psychiatric disorders. Moderate renal impairment. Monitor for impulse control disorders incl pathological gambling, hypersexuality, compulsive spending or eating. Elderly. Withdraw gradually.
Interactions
Anticholinergic agents, L-dopa, diuretics combination, antipsychotics, other centrally acting agents.
Advice to Patient
Take last dose in afternoon. Do not stop taking medication abruptly, gradually lower the dose and then stop. Contact prescriber if there is difficulty in breathing, unusual swelling of extremities, increased tremors, change in gait, change in mental status, anxiety, depression, irritability, speech impairment, hallucination. Contact prescriber if influenza symptoms do not improve after 2 to 3 days or there is increased urge for any activity. Take sufficient amount of fluids (2-3 litres per day) to maintain hydration, unless restricted by the prescriber. Change position slowly from sitting or lying to standing. Empty bladder before taking medication. Avoid alcohol during therapy. Have regular skin examinations by dermatologist. On start of therapy or change of dosage, patient must be watched for suicidal tendency.
Pharmacokinetics
Onset of action: Antidyskinetic: Within 48 hrs. Absorption: Well absorbed. Metabolism: Not appreciable; small amounts of an acetyl metabolite identified. Bioavailability: Immediate release: 86%-94%. Half-life elimination: Normal renal function: 16 ± 6 hrs; Healthy, older (=60 yrs) males: 29 hrs; End-stage renal disease: 8 days. Time to peak, plasma: Extended release: 12 hrs; Immediate release: 2-4 hrs. Excretion: Urine (80%-90% unchanged) by glomerular filtration and tubular secretion.
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
Always consult a pharmacist or doctor.