Dosing and uses of Flumadine (rimantadine)
Adult dosage forms and strengths
syrup
- 50mg/5mL
tablet
- 100mg
Influenza A Virus
Prophylaxis
- 100 mg PO BID
Treatment
- 100 mg PO BID preferably within 48 hours after onset of signs and symptoms of influenza A infection.
Geriatric, CrCl <10 mL/min, severe liver impairment: give qd
Pediatric dosage forms and strengths
syrup
- 50mg/5mL
tablet
- 100mg
Influenza A Virus
Children 1-9 years old and Children >10 years old who weigh <40 kg: 5 mg/kg PO qD-BID, no more than 150mg/day
Children >10 years old who weigh >40 kg 100mg PO BId
Flumadine (rimantadine) adverse (side) effects
1-10%
Orthostatic hypotension
Edema
Dizziness (2%)
Confusion
Headache (1%)
Insomnia (2%)
Difficulty in concentrating
Anxiety (1%)
Restlessness
Irritability
Hallucinations
Incidence of CNS side effects may be less than that associated with amantadine
Nausea (3%)
Vomiting (2%)
Xerostomia (2%)
Abdominal pain (1%)
Anorexia (2%)
Urinary retention
Warnings
Contraindications
Allergy to amantadine, rimantadine
Cautions
CDC advises against use for Tx or prophylaxis of influenza in the US during the 2008-09 influenza season
Discontinue if seizures occur
Pregnancy and lactation
Pregnancy category: C
Lactation: enters breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Flumadine (rimantadine)
Onset of action: antiviral activity: no data exist establishing a correlation between plasma concentration & antiviral effect
Absorption: tablet and syrup formulations are equally absorbed
Metabolism: extensively hepatic
Half-life elimination: 25.4 hr; prolonged in elderly
Peak Plasma Time: 6 hr
Excretion: urine (<25% as unchanged drug)
Clearance: hemodialysis does not contribute to clearance
Mechanism of action
Inhibits viral replication of influenza A
