Amantadine Sulfate

What it is and how it works

Mechanism of Action Antiviral 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. In certain cases, 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.

Indications

INDICATIONS AND USAGE Amantadine Hydrochloride Oral Solution USP is indicated for the prophylaxis and treatment of signs and symptoms of infection caused by various strains of influenza A virus. Amantadine Hydrochloride Oral Solution USP is also indicated in the treatment of parkinsonism and drug-induced extrapyramidal reactions. Influenza A Prophylaxis Amantadine Hydrochloride Oral Solution USP is indicated for chemoprophylaxis against signs and symptoms of influenza A virus infection. Because Amantadine Hydrochloride Oral Solution USP does not completely prevent the host immune response to influenza A infection, individuals who take this drug may still develop immune responses to natural disease or vaccination and may be protected when later exposed to antigenically related viruses. Following vaccination during an influenza A outbreak, Amantadine Hydrochloride Oral Solution USP prophylaxis should be considered for the 2- to 4-week time period required to develop an antibody response.

Dosage and administration (summary)

DOSAGE AND ADMINISTRATION The dose of Amantadine Hydrochloride Oral Solution USP (Amantadine Hydrochloride, USP) may need reduction in patients with congestive heart failure, peripheral edema, orthostatic hypotension, or impaired renal function (see Dosage for Impaired Renal Function ). Dosage for Prophylaxis and Treatment of Uncomplicated Influenza A Virus Illness Adult The adult daily dosage of Amantadine Hydrochloride Oral Solution USP is 200 mg; two 100 mg tablets (or four teaspoonfuls of syrup) as a single daily dose. The daily dosage may be split into one tablet of 100 mg (or two teaspoonfuls of syrup) twice a day.

Contraindications

CONTRAINDICATIONS Amantadine Hydrochloride Oral Solution USP is contraindicated in patients with known hypersensitivity to amantadine hydrochloride or to any of the other ingredients in Amantadine Hydrochloride Oral Solution USP.

Warnings and precautions

WARNINGS Deaths Deaths have been reported from overdose with Amantadine Hydrochloride Oral Solution USP. The lowest reported acute lethal dose was 1 gram. Acute toxicity may be attributable to the anticholinergic effects of amantadine. Drug overdose has resulted in cardiac, respiratory, renal or central nervous system toxicity. Cardiac dysfunction includes arrhythmia, tachycardia and hypertension (see OVERDOSAGE ).

Pregnancy

Pregnancy Category C The effect of amantadine on embryofetal and peri-postnatal development has not been adequately tested, that is, in studies conducted under Good Laboratory Practice (GLP) and according to current recommended methodology.

Storage and supply

Store at 20°-25°C (68°-77°F), excursions permitted to 15°-30°C (59°-86°F). . Dispense in a tight container as defined in the USP, with a child-resistant closure (as required).

Source: Amantadine Hydrochloride (Amantadine Hydrochloride) — US FDA prescribing information, 2024-05-20, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.