Classifications: antiviral; anticholinergic; antiparkinson agent; Therapeutic:antiviral; antiparkinson agent
Pregnancy Category: C
100 mg capsules; 50 mg/5 mL syrup
Because it does not suppress antibody formation, it can be administered for interim protection in combination with influenza
A virus vaccine until antibody titer is adequate or to augment prophylaxis in a previously vaccinated individual. Mechanism
of action in parkinsonism may be related to release of dopamine and other catecholamines from neuronal storage sites.
Active against several strains of influenza A virus; not effective against influenza B infections.
In initial therapy or as adjunct with anticholinergic drugs or levodopa in treatment of all forms of parkinsonism (arteriosclerotic,
idiopathic, postencephalitic) and for relief of drug-induced extrapyramidal reactions and symptomatic parkinsonism caused
by carbon monoxide poisoning. Also used for prophylaxis and symptomatic treatment of influenza A infections.
Primary enuresis, pseudosclerosis, neuroleptic malignant syndrome (NMS), management of cocaine dependency and withdrawal.
Hypersensitivity to amantadine or rimantadine, closed angle glaucoma; suicidal ideation; pregnancy (category C); lactation.
Safety in children <1 y is not established.
History of epilepsy or other types of seizures; CHF, peripheral edema, orthostatic hypotension; recurrent eczematoid dermatitis;
psychoses, severe psychoneuroses; hepatic disease; renal impairment; older adults with cerebral arteriosclerosis.
Route & Dosage
Adult: PO 200 mg once/d or 100 mg q12h
Child (19 y): PO 4.48.8 mg/kg in 23 equal doses (max: 150 mg/d)
Adult: PO 100 mg 12 times/d, start with 100 mg/d if patient is on other antiparkinsonism medications
Drug-Induced Extrapyramidal Symptoms
Adult: PO 100 mg b.i.d. (max: 400 mg/d if needed)
Clcr 4060 mL/min: 100 mg/d; 3040 mL/min: 200 mg 2 times/wk; 1020 mL/min: 100 mg 3 times/wk
- Give with water, milk, or food.
- Use supplied calibrated device for measuring syrup formulation.
- Influenza prophylaxis: Drug should be initiated when exposure is anticipated and continued for at least 10 d.
- Note: Used in conjunction with influenza A vaccine (generally in high-risk patients who have not been vaccinated previously) until
protective antibodies develop (1021 d) after vaccine administration.
- Schedule medication in the morning or, with q12h dosing, schedule 2nd dose several hours before bedtime. If insomnia is
a problem, suggest patient limit number of daytime naps.
- Store in tightly closed container preferably at 15°30° C (59°86° F) unless otherwise directed
by manufacturer. Avoid freezing.
Adverse Effects (≥1%)CNS: Dizziness, light-headedness,
headache, ataxia, irritability, anxiety, nervousness, difficulty in concentrating,
mood or other mental changes, confusion, visual and auditory hallucinations, insomnia,
nightmares, convulsions. CV:
Orthostatic hypotension, peripheral edema, dyspnea. Special Senses:
Blurring or loss of vision. GI:
vomiting, dry mouth. Hematologic:
enhances CNS effects; may potentiate effects of anticholinergics
Almost completely absorbed from GI tract. Onset:
Within 48 h. Peak:
14 h. Distribution:
Through body fluids. Metabolism:
Not metabolized. Elimination:
90% unchanged in urine. Half-Life:
937 h (prolonged in renal insufficiency).
Assessment & Drug Effects
- Monitor effectiveness. Note that with parkinsonism, maximum response occurs within 2 wk3 mo. Effectiveness may wane
after 68 wk of treatment; report change to physician.
- Monitor and report: Mental status changes; nervousness, difficulty concentrating, or insomnia; loss of seizure control;
S&S of toxicity, especially with doses above 200 mg/d.
- Establish a baseline profile of the patient's disabilities to accurately differentiate disease symptoms and drug-induced
neuropsychiatric adverse reactions.
- Monitor vital signs for at least 3 or 4 d after increases in dosage; also monitor urinary output.
- Lab tests: pH and serum electrolytes.
- Monitor for and report reduced salivation, increased akinesia or rigidity, and psychological disturbances that may develop
within 448 h after initiation of therapy and after dosage increases with parkinsonism.
Patient & Family Education
- Note: For influenza take within 24 h but no later than 48 h after onset of symptoms for effective response and continue for 2448
h after symptoms disappear; contact physician if no improvement within this time.
- Make all position changes slowly, particularly from recumbent to upright position, in order to minimize dizziness.
- Report any of the following to physician: Shortness of breath, peripheral edema, significant weight gain, dizziness or lightheadedness,
inability to concentrate, and other changes in mental status, difficulty urinating, and visual impairment.
- Do not drive and exercise caution with potentially hazardous activities until response to the drug is known.
- Note: People with Parkinson's disease should not discontinue therapy abruptly; doing so may precipitate a parkinsonian crisis
with severe akinesia, rigidity, tremor, and psychic disturbances. Adhere to established dosage regimen.