Therapeutic Classification: antiparkinson agents, antivirals
Absorption: Well absorbed from the GI tract.
Distribution: Distributed to various body tissues and fluids. Crosses blood-brain barrier.
Metabolism/Excretion: Excreted unchanged in the urine.
Half-Life: 10–28 hr.
- Extended-release products are not interchangeable with immediate-release products.
Parkinson’s Disease
- PO (Adults ): Immediate release: 100 mg twice daily; may ↑ to max of 400 mg/day in divided doses;Extended release: 137 mg once daily at bedtime; may ↑ after 1 wk to 274 mg once daily at bedtime.
Drug-Induced Extrapyramidal Reactions
- PO (Adults ): Immediate release: 100 mg twice daily; may ↑ at weekly intervals (max dose = 300 mg/day in divided doses).
Influenza A Infection
- PO (Adults and Children >12 yr): Treatment (immediate release): 200 mg/day as a single dose or 100 mg bid (not >100 mg/day in geriatric patients); Prophylaxis (immediate release): 100 mg/day in 1–2 divided doses.
- PO (Children 10–12 yr): Immediate release: 100 mg every 12 hr or 5 mg/kg/day in 1–2 divided doses; not to exceed 200 mg/day.
- PO (Children 1–9 yr): Immediate release: 5 mg/kg/day in 1–2 divided doses; not to exceed 150 mg/day.
Renal Impairment
- PO (Adults ): CCr 30–50 mL/min: Immediate release: 200 mg on the first day; then 100 mg once daily; CCr 15–29 mL/min: Immediate release: 200 mg on the first day; then 100 mg every other day; <15 mL/min or hemodialysis patients: Immediate release: 200 mg once every 7 days.
Renal Impairment
- PO (Adults ): CCr 30–59 mL/min: Extended release: 68.5 mg once daily at bedtime; may ↑ after 1 wk to 137 mg once daily at bedtime; Extended release: 129 mg every 48 hr in the morning; may ↑ every 3 wk (max dose = 322 mg every 48 hr in the morning); CCr 15–29 mL/min: Extended release: 68.5 mg once daily at bedtime (max dose = 68.5 mg/day); Extended release: 129 mg every 96 hr in the morning; may ↑ every 4 wk (max dose = 322 mg every 96 hr in the morning); <15 mL/min or hemodialysis patients: Extended release: Contraindicated.
