Yes

Anti-Parkinson's Agent (Dopamine Agonist); Antiviral Agent

Prophylaxis and treatment of influenza A viral infection; treatment of parkinsonism; treatment of drug-induced extrapyramidal reactions

C

Hypersensitivity to amantadine or any component

Use with caution in patients with liver disease, history of recurrent and eczematoid dermatitis, uncontrolled psychosis or severe psychoneurosis, seizures, and in those receiving CNS stimulant drugs; reduce dose in renal disease. When treating Parkinson's disease, do not discontinue abruptly. In many patients, the therapeutic benefits of amantadine are limited to a few months. Elderly patients may be more susceptible to CNS effects (using 2 divided daily doses may minimize this effect). Has been associated with neuroleptic malignant syndrome (associated with dose reduction or abrupt discontinuation). Use with caution in patients with CHF, peripheral edema, or orthostatic hypotension. Avoid in angle closure glaucoma.

1% to 10%:

Cardiovascular: Orthostatic hypotension, peripheral edema

Central nervous system: Insomnia, depression, anxiety, irritability, dizziness, hallucinations, ataxia, headache, somnolence, nervousness, dream abnormality, agitation, fatigue, confusion

Dermatologic: Livedo reticularis

Gastrointestinal: Nausea, anorexia, constipation, diarrhea, xerostomia

Respiratory: Dry nose

<1%: Congestive heart failure, hypertension, psychosis, slurred speech, euphoria, amnesia, instances of convulsions, rash, eczematoid dermatitis, decreased libido, urinary retention, vomiting, leukopenia, neutropenia, hyperkinesis, weakness, visual disturbances, oculogyric episodes, dyspnea

Symptoms of overdose include nausea, vomiting, slurred speech, blurred vision, lethargy, hallucinations, seizures, myoclonic jerking

Following GI decontamination, treatment should be directed at reducing the CNS stimulation and at maintaining cardiovascular function. Seizures can be treated with diazepam while a lidocaine infusion may be required for the cardiac dysrhythmias.

Anticholinergics (benztropine and trihexyphenidyl) may potentiate CNS side effects of amantadine; monitor for altered response

Hydrochlorothiazide plus triamterene may increase serum levels and toxicity of amantadine; monitor for altered response

Protect from freezing

As an antiviral, blocks the uncoating of influenza A virus preventing penetration of virus into host; antiparkinsonian activity may be due to its blocking the reuptake of dopamine into presynaptic neurons or by increasing dopamine release from presynaptic fibers

Onset of antidyskinetic action: Within 48 hours

Absorption: Well absorbed from GI tract

Distribution: To saliva, tear film, and nasal secretions; in animals, tissue (especially lung) concentrations higher than serum concentrations, crosses blood-brain barrier

V_d: Normal: 4.4±0.2 L/kg; Renal failure: 5.1±0.2 L/kg

Protein binding:

Normal renal function: ~67%

Hemodialysis patients: ~59%

Metabolism: Not appreciable, small amounts of an acetyl metabolite identified

Half-life: 10-28 hours; Impaired renal function: 7-10 days

Time to peak: 1-4 hours

Elimination: 80% to 90% excreted unchanged in urine by glomerular filtration and tubular secretion

Children: Influenza:

1-9 years: (<45 kg): 5-9 mg/kg/day in 1-2 divided doses to a maximum of 150 mg/day

10-12 years: 100-200 mg/day in 1-2 divided doses

Influenza prophylaxis: Administer for 10-21 days following exposure if the vaccine is concurrently given or for 90 days following exposure if the vaccine is unavailable or contraindicated and re-exposure is possible

Adults:

Drug-induced extrapyramidal reactions: 100 mg twice daily; may increase to 300-400 mg/day, if needed

Parkinson's disease: 100 mg twice daily as sole therapy; may increase to 400 mg/day if needed with close monitoring; initial dose: 100 mg/day if with other serious illness or with high doses of other anti-Parkinson drugs

Influenza A viral infection: 200 mg/day in 1-2 divided doses

Influenza prophylaxis: Minimum 10-day course of therapy following exposure if the vaccine is concurrently given or for 90 days following exposure if the vaccine is unavailable or contraindicated and re-exposure is possible

Elderly patients should take the drug in 2 daily doses rather than a single dose to avoid adverse neurologic reactions

Dosing interval in renal impairment:

Cl_cr 50-60 mL/minute: Administer 200 mg alternating with 100 mg/day

Cl_cr 30-50 mL/minute: Administer 100 mg/day

Cl_cr 20-30 mL/minute: Administer 200 mg twice weekly

Cl_cr 10-20 mL/minute: Administer 100 mg 3 times/week

Cl_cr <10 mL/minute: Administer 200 mg alternating with 100 mg every 7 days

Hemodialysis: Slightly hemodialyzable (5% to 20%); no supplemental dose is needed

Peritoneal dialysis: No supplemental dose is needed

Continuous arterio-venous or venous-venous hemofiltration (CAVH/CAVHD): No supplemental dose is needed

Avoid alcohol

Renal function, mental status, blood pressure

No information available to require special precautions

>10% of patient experience dry mouth; prolonged use of amantadine may cause significant xerostomia

Take as directed; do not increase dosage, take more often than prescribed, or discontinue without consulting prescriber. Maintain adequate hydration (2-3 L/day of fluids unless instructed to restrict fluid intake) and void before taking medication. Take last dose of day in the afternoon to reduce incidence of insomnia. Avoid alcohol, sedatives, or hypnotics unless consulting prescriber. You may experience decreased mental alertness or coordination (use caution when driving, climbing stairs, or engaging in tasks requiring alertness until response to drug is known); nausea, or dry mouth (small frequent meals, frequent mouth care, sucking lozenges, or chewing gum may help). Report unusual swelling of extremities, difficulty breathing or shortness of breath, change in gait or increased tremors, or changes in mentation (depression, anxiety, irritability, hallucination, slurred speech). Pregnancy/breast-feeding precautions: Inform prescriber if you are pregnant. Consult prescriber if breast-feeding.

If insomnia occurs, the last daily dose should be given several hours before retiring; assess parkinsonian symptoms prior to and throughout course of therapy

Capsule, as hydrochloride: 100 mg

Syrup, as hydrochloride: 50 mg/5 mL (480 mL)

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