Brands, Medical Use, Clinical Data
- Antiviral Agents
- Nucleic Acid Synthesis Inhibitors
- Available as 100 mg film-coated tablets and as syrup for oral administration.
Brands / Synonyms
Flumadine; Levofloxacin hydrochloride; Rimantadine HCL
For the prophylaxis and treatment of illness caused by various strains of influenza A virus in adults.
Rimantadine, a cyclic amine, is a synthetic antiviral drug and a derivate of adamantane, like a similar drug amantadine. Rimantadine is inhibitory to the in vitro replication of influenza A virus isolates from each of the three antigenic subtypes (H1N1, H2H2 and H3N2) that have been isolated from man. Rimantadine has little or no activity against influenza B virus. Rimantadine does not appear to interfere with the immunogenicity of inactivated influenza A vaccine.
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.
Well absorbed, with the tablet and syrup formulations being equally absorbed after oral administration.
Oral LD50 in rats is 640 mg/kg. Overdoses of a related rug, amantadine, have been reported with adverse reactions consisting of agitation, hallucinations, cardiac arrhythmia and death.
Biotrnasformation / Drug Metabolism
Following oral administration, rimantadine is extensively metabolized in the liver with less than 25% of the dose excreted in the urine as unchanged drug. Glucuronidation and hydroxylation are the major metabolic pathways.
Rimantadine HCl is contraindicated in patients with known hypersensitivity to drugs of the adamantine class,
including rimantadine and amantadine.
Cimetidine: The effects of chronic cimetidine use on the metabolism of rimantadine are not known. When a
single 100 mg dose of rimantadine HCl was administered one hour after the initiation of Cimetidine (300 mg four times
a day), the apparent total rimantadine clearance of this single dose in normal healthy adults was reduced by 18%
(compared to the apparent total rimantadine clearance in the same subjects in the absence of cimetidine).
Acetaminophen: Rimantadine HCl, 100 mg, was given twice daily for 13 days to 12 healthy volunteers. On day
11, acetaminophen (650 mg four times daily) was started and continued for 8 days. The pharmacokinetics of rimantadine
were assessed on days 11 and 13. Coadministration with acetaminophen reduced the peak concentration and AUC values
for rimantadine by approximately 11%.
Aspirin: Rimantadine HCl, 100 mg, was given twice daily fro 13 days to 12 healthy volunteers. On day 11,
aspirin (650 mg, four times daily) was started and continued for 8 days. The pharmacokinetics of rimantadine were
assessed on days 11 and 13. Peak plasma concentrations and AUC of rimantadine were reduced approximately 10% in the
presence of aspirin.