Interacting drugs- summary

+ Rimantadine-

Acetaminophen +   
Coadmin with acetoaminophen reduced the peak concentration
and AUC values for rimantadine

Aspirin  + 
 Peak plasma and AUC of rimantadine reduced

Cimetidine +
 When  a single dose of 100mg of rimantadine was administered
 1 hour after cimetidine(300mg 4 times a day) in healthy adults,
  the apparent total rimantadine clearance was reduced by 16%
  

Prophylaxis against influenza virus 

Most frequently reported adverse events invloved GI and CNS

CNS-

Insomnia 2% dizziness 2% headache 1% nervousness 1% fatigue 1% asthenia 1.4%

GI-

Nausea 3% vomiting 2% anorexia 2% dry mouth 2% abdominal pain 1%

Hypersens to drugs of the adamantine class, incuding rimantadine and amantadine

Special precautions:

Seizures- increased in patients with history of epilepsy.

Resistence - emergence of resistence strains of influenza virus during treatment

Seizures- an increased incidence of seizures has been reported in patients with a history of epilepy who received the related drug amantadine. If seizures develop discontinue the drug.

Resistence- consider transmission of rimantadine- resistent virus when treating patients whose contacts are at high risk for infuenza A illness.

Influenza A virus strains resistent to rimantidine can emerge during treatment and may be transmissible and cause typical influenza illness.

Warnings-

Renal/hepatic function impairment- the safety and pharmacokinetics of rimantidine in renal and hepatic insufficiency have not been evaluated after single dose administration.

Because of the potential accumulation of rimantidine and its metabolites in polasma, excercise caution when patients with renal or hepatic insufficiency are treated with rimantadine.

Pregnancy- Use during pregnancy only if the potential benefits justifies the risk to the fetus.

Lacatation- Rimatadine should not be administered to nursing mothers because of the adverse effects noted in the offsping of rats treated with rimantidine during the nursing period.

Children- safety and efficacy of rimantadine in the treatment of symptomatic influenza infection in children have not been established.

Approved by FDA on September 17,1993

Indications:

Prophylaxis against influenza virus

Dosage:

Adults- recommended dose- 100mg twice daily

Children below 10 years- administer once a day at a dose of 5mg/kg not exceeding 150mg.

Pharmacology:

Rimantadine is a synthetic antiviral agent. The mechanism of action is not understood.It appears to exert its inhibitory effect early in viral replicative cycle, possibly inhibiting the uncoating of the virus.

Pharmacokinetics-

There are no data establishing a correlation between plasma concentration and antiviral effect.

Pregnancy:

Use only if the potential benefits outweighs the potential risks to the fetus. Lactation: Rimantadine should not be administered to nursing mothers.

Children-

Safety and efficacy of rimantadine in the treatment of symptomatic inflenza infection in children have not been established.