Flumadine (rimantadine HCl)

Unlike amantadine, which is eliminated unchanged, rimantadine is extensively metabolized in the liver. Because of potential accumulation of rimantadine and/or its metabolites in plasma, the drug should be used with caution in patients with hepatic impairment and such patients should be monitored for adverse effects. If rimantadine hydrochloride is used in patients with severe hepatic impairment, dosage should be reduced to 100 mg daily.

Because of potential accumulation of rimantadine and/or its metabolites in plasma, the drug should be used with caution in patients with renal impairment and such patients should be monitored for adverse effects. If rimantadine hydrochloride is used in patients with severe renal impairment (creatinine clearance 5-29 mL/minute) or renal failure (creatinine clearance 10 mL/minute or less), dosage should be reduced to 100 mg daily.

Rimantadine hydrochloride is administered orally.

Rimantadine hydrochloride is commercially available as tablets containing 100 mg of the drug.

For use only during emergency situations for patients who cannot swallow tablets or when lower dosage is needed, rimantadine hydrochloride oral suspensions containing 10 mg/mL can be prepared extemporaneously using the 100-mg tablets of the drug. The manufacturer's information should be consulted for specific directions on how to prepare extemporaneous oral suspensions of the drug.

There is no enhanced messaging for this drug.

Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

Selected Antiviral Agents/Influenza Virus Vaccine Live

SEVERITY LEVEL: 1-Contraindicated Drug Combination: This drug combination is contraindicated and generally should not be dispensed or administered to the same patient.

MECHANISM OF ACTION: Amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir,(4) and baloxavir,(5) may inactivate the intranasal live influenza virus vaccine, preventing the body from developing an immune response.

CLINICAL EFFECTS: Administration of amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir,(4) and baloxavir,(5) may render the intranasal live influenza virus vaccine ineffective.

PREDISPOSING FACTORS: None determined.

PATIENT MANAGEMENT: The US manufacturers of amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir(4), baloxavir(5), and the intranasal live influenza virus vaccine(6) state that these agents should not be initiated within 2 weeks of the administration of the intranasal live influenza virus vaccine and that the vaccine should not be administered within 48 hours of the discontinuation of these agents. Inactivated influenza vaccine may be used at any time.(1)

DISCUSSION: Because antiviral drugs such as amantadine,(1) oseltamivir,(2) rimantadine,(3) zanamivir,(4) and baloxavir (5) inhibit the replication of live viruses, these agents may interfere with the efficacy of the intranasal live influenza virus vaccine.

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

There is no enhanced messaging for this drug.

There are no contraindication contraindications for this drug.

• Chronic kidney disease stage 4 (severe) GFR 15-29 ml/min
• Chronic kidney disease stage 5 (failure) GFr<15 ml/min
• Seizure disorder

• Disease of liver
• Kidney disease with likely reduction in glomerular filtration rate (GFr)
• Kidney disease with reduction in glomerular filtration rate (GFr)

There is no enhanced messaging for this drug.

Rare or Very Rare

• Dyspnea

Less Frequent

• Abdominal pain with cramps
• Concentration difficulty
• Dizziness
• Fatigue
• Gastrointestinal irritation
• General weakness
• Headache disorder
• Insomnia
• Nausea
• Nervousness
• Symptoms of anxiety
• Vomiting
• Xerostomia

Rare or Very Rare

• Agitation
• Anorexia
• Ataxia
• Depression
• Diarrhea
• Drowsy
• Skin rash
• Tinnitus

No enhanced messaging available.

No enhanced messaging available.

There are no adequate and well-controlled studies using rimantadine in pregnant women, and the drug should be used during pregnancy only when the potential benefits justify the possible risks to the fetus.

Rimantadine hydrochloride has been reported to be embryotoxic (i.e., increased fetal resorption) in rats when administered in a dosage of 200 mg/kg daily (11 times the MRHD based on mg/m2); this dose also was associated with several maternal effects including ataxia, tremor, seizures, and substantially reduced weight gain. In rabbits, developmental abnormality (i.e., change in the ratio of fetuses with 12 or 13 ribs) was observed with rimantadine hydrochloride dosages of 50 mg/kg daily (approximately 0.1 times the MRHD based on AUC), but embryotoxicity was not observed and this abnormality did not occur when a repeat embryofetal toxicity study was performed using the same dosage. Reproductive studies in rats given rimantadine hydrochloride dosages of 30, 60, or 120 mg/kg daily (1.7, 3.4, or 6.8 times the MRHD based on mg/m2) during the perinatal and postnatal period have shown an increase in pup mortality during the first 2-4 days postpartum in rats given the 120-mg/kg daily dosage, and maternal toxicity during gestation in rats given the 60- or 120-mg/kg daily dosage.

Rimantadine hydrochloride should not be used in nursing women. Studies in rats indicate that rimantadine is distributed into milk and adverse effects have been noted in offspring of rats given the drug during the nursing period.

No enhanced messaging available.