FLUMADINE- rimantadine hydrochloride tablet
FLUMADINE- rimantadine hydrochloride syrup
FOREST PHARMACEUTICALS, INC.
DESCRIPTION
Flumadine� (rimantadine hydrochloride) is a synthetic antiviral drug available as a 100 mg film-coated tablet and as a syrup for oral administration. Each film-coated tablet contains 100 mg of rimantadine hydrochloride plus hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, sodium starch glycolate, FD&C Yellow No. 6 Lake and FD&C Yellow No. 6. The film coat contains hydroxypropyl methylcellulose and polyethylene glycol. Each teaspoonful (5 mL) of the syrup contains 50 mg of rimantadine hydrochloride in an aqueous solution containing citric acid, parabens (methyl and propyl), saccharin sodium, sorbitol, D&C Red No. 33 and flavors.
Rimantadine hydrochloride is a white to off-white crystalline powder which is freely soluble in water (50 mg/mL at 20�C). Chemically, rimantadine hydrochloride is alpha-methyltricyclo-[3.3.1.1/3.7]decane-1-methanamine hydrochloride, with an empirical formula of C12 H21 N�HCI, a molecular weight of 215.77 and the following structural formula:Image from Drug Label Content
CLINICAL PHARMACOLOGY
MECHANISM OF ACTION: The mechanism of action of rimantadine is not fully understood. Rimantadine appears to exert its inhibitory effect early in the viral replicative cycle, possibly inhibiting the uncoating of the virus. Genetic studies suggest that a virus protein specified by the virion M2 gene plays an important role in the susceptibility of influenza A virus to inhibition by rimantadine.
MICROBIOLOGY: Rimantadine is inhibitory to the in vitro replication of influenza A virus isolates from each of the three antigenic subtypes, i.e., H1N1, H2N2 and H3N2, that have been isolated from man. Rimantadine has little or no activity against influenza B virus (Ref. 1,2). Rimantadine does not appear to interfere with the immunogenicity of inactivated influenza A vaccine.
A quantitative relationship between the in vitro susceptibility of influenza A virus to rimantadine and clinical response to therapy has not been established.
Susceptibility test results, expressed as the concentration of the drug required to inhibit virus replication by 50% or more in a cell culture system, vary greatly (from 4 ng/mL to 20 ? g/mL) depending upon the assay protocol used, size of the virus inoculum, isolates of the influenza A virus strains tested, and the cell types used (Ref. 2).
Rimantadine-resistant strains of influenza A virus have emerged among freshly isolated epidemic strains in closed settings where rimantadine has been used. Resistant viruses have been shown to be transmissible and to cause typical influenza illness. (Ref. 3)
PHARMACOKINETICS: Although the pharmacokinetic profile of Flumadine has been described, no pharmacodynamic data establishing a correlation between plasma concentration and its antiviral effect are available.
