Rimantadine is an orally administered medicine used to treat, and in rare cases prevent, type A influenza. When taken within one to two days of developing symptoms, rimantadine can shorten the duration and moderate the severity of influenza.

Mechanics

Scientists do not understand why rimantadine works, but believe it inhibits influenza's viral replication, possibly by preventing the uncoating of the virus's protective shells, which are the envelope and capsid. Genetic studies suggest that a virus protein specified by virion M2 gene plays an important role in the susceptibility of influenza A virus to inhibition by rimantadine.

Drug Interactions

Taking acetaminophen (Tylenol) or aspirin while taking rimantadine is known to reduce the body's uptake of rimantadine by approximately 10%.[1] Cimetidine also affects the body's uptake of rimantadine.

Side Effects

Rimantadine can produce gastrointestinal and central nervous system side effects. Studies have shown it produces fewer side effects than other anti-viral influenza treatments. Approximately 6% of patients (compared to 4% of patients taking a placebo) reported side effects.[2] Common side effects include:

• nausea
• upset stomach
• nervouseness
• tiredness
• lightheadedness
• trouble sleeping
• difficulty concentrating

External Links

• U.S. FDA press release announcing rimantadine's approval
• U.S. Center for Drug Evaluation and Research rimantadine description
• U.S. NIH rimantadine description
• U.S. CDC flu anti-viral treatment information