Adults

Treatment of influenza: One 250 mg capsule once daily for 5 days. Treatment should begin within 2 days of symptom onset. Prophylaxis of influenza: One 250 mg capsule once daily for 10 days, or as directed by physician. This strength is higher than standard Oseltamivir doses and specific medical guidance is essential.

Elderly

No dose adjustment typically required, but caution is advised in elderly patients with impaired renal function.

Renal_impairment

Dose adjustment required for patients with creatinine clearance less than or equal to 30 mL/min. Consult physician for specific dosage based on renal function.

Onset

Within 1-2 hours for active metabolite concentration.

Excretion

Excreted primarily via the kidneys as the active metabolite. More than 90% of the active metabolite is excreted unchanged in urine.

Half life

Approximately 6-10 hours for the active metabolite.

Absorption

Rapidly absorbed from the gastrointestinal tract and extensively converted to the active metabolite, oseltamivir carboxylate, by hepatic esterases. Bioavailability of the active metabolite is about 75%.

Metabolism

Primarily metabolized in the liver by esterases to its active form, oseltamivir carboxylate. No further metabolism of oseltamivir carboxylate is observed.

Probenecid

Coadministration with probenecid results in approximately a 2.5-fold increase in exposure to oseltamivir carboxylate due to competition for renal tubular secretion, but dose adjustment is generally not required unless renal function is already impaired.

Live attenuated influenza vaccine

Avoid concurrent use; Oseltamivir may interfere with the replication of the live vaccine. Do not administer Oseltamivir within 2 weeks after vaccination or within 48 hours before vaccination with live attenuated influenza vaccine.