OSELTA 75/MG CAP 10/CAP

Indications

Approved Uses

Treatment of acute, uncomplicated influenza A and B in patients ≥2 weeks of age who have been symptomatic for no more than 48 hours; prophylaxis of influenza A and B in patients ≥1 year of age.

Off-Label Uses

Off-label: treatment of severe/complicated influenza (including hospitalized patients) and avian influenza (e.g., H5N1) using higher/longer regimens per public-health guidance; prophylaxis in high-risk/immunocompromised patients may be used per specialist/public-health protocols.

Dosage & Administration

Dosing by Condition

Treatment of influenza (adults): 75mg twice daily for 5 days. Prophylaxis of influenza (adults): 75mg once daily for at least 10 days (post-exposure) or up to 6 weeks (seasonal). Severe influenza or immunocompromised: 75mg twice daily for 10 days

Initial Dose

75mg twice daily for influenza treatment.

Maintenance Dose

75mg twice daily (treatment) or 75mg once daily (prophylaxis)

Maximum Dose

150mg per day for influenza treatment.

Children's Dosage

Weight-based dosing for children 1 year and older: ≤15kg: 30mg twice daily (treatment) or 30mg once daily (prophylaxis); >15 to 23kg: 45mg twice daily (treatment) or 45mg once daily (prophylaxis); >23 to 40kg: 60mg twice daily (treatment) or 60mg once daily (prophylaxis); >40kg: 75mg twice daily (treatment) or 75mg once daily (prophylaxis). For infants 2 weeks to <1 year: 3 mg/kg twice daily for 5 days (treatment).

Dose Adjustment Notes

Dose reduction is required in renal impairment (clinically relevant when CrCl ≤60 mL/min, with larger reductions at lower CrCl); pediatric dosing is weight-based; no adjustment is needed for mild-to-moderate hepatic impairment.

How to Take

Swallow capsule whole with water; may be taken with or without food, but taking with food can reduce nausea/vomiting; start treatment as soon as possible, ideally within 48 hours of symptom onset.

Side Effects

Common Side Effects

Nausea, vomiting, headache, abdominal pain, diarrhea, dizziness

Side Effect Frequency

Very common (≥10%): nausea, vomiting. Common (1-10%): headache (and may include abdominal pain/diarrhea depending on source/population). Uncommon/rare: hypersensitivity/serious skin reactions and neuropsychiatric events.

Safety & Warnings

Contraindications

Known serious hypersensitivity to oseltamivir or any component/excipient of the product.

Warnings & Precautions

Not a substitute for influenza vaccination; start as early as possible (ideally within 48 hours of symptom onset); monitor for neuropsychiatric events (especially in children/adolescents); watch for serious skin/hypersensitivity reactions; adjust dose in renal impairment.

Age Restriction

Treatment: approved for patients ≥2 weeks of age; Prophylaxis: approved for patients ≥1 year of age (younger ages may be used off-label per guidelines with weight-based dosing).

Drug Interactions

Food Interaction

May be taken with or without food; taking with food is recommended if gastrointestinal upset occurs (food does not meaningfully reduce overall exposure).

Special Populations

Pregnancy

No human or animal data. Use only if potential benefit justifies potential risk to the fetus.

Children

Weight-based dosing for children 1 year and older: ≤15kg: 30mg twice daily (treatment) or 30mg once daily (prophylaxis); >15 to 23kg: 45mg twice daily (treatment) or 45mg once daily (prophylaxis); >23 to 40kg: 60mg twice daily (treatment) or 60mg once daily (prophylaxis); >40kg: 75mg twice daily (treatment) or 75mg once daily (prophylaxis). For infants 2 weeks to <1 year: 3 mg/kg twice daily for 5 days (treatment).

Elderly

Standard adult dosing; renal function should be assessed as dose adjustment may be required if CrCl is reduced

Kidney Impairment

Treatment: CrCl >30-60 mL/min: 30 mg twice daily; CrCl >10-30 mL/min: 30 mg once daily. Prophylaxis: CrCl >30-60 mL/min: 30 mg once daily; CrCl >10-30 mL/min: 30 mg every other day. (ESRD/dialysis: requires specific regimen per modality; not covered in all labels.)

Liver Impairment

No dose adjustment needed in mild-to-moderate hepatic impairment; not studied/insufficient data in severe hepatic impairment.

Storage & Patient Advice

Stopping the Medicine

Complete the full prescribed course (typically 5 days for treatment) even if symptoms improve earlier.

Patient Counseling

Start as soon as possible (ideally within 48 hours of symptoms for treatment). Take with or without food; take with food if stomach upset occurs. Complete the full prescribed course (commonly 5 days for treatment; once daily for prophylaxis for the prescribed duration). Report unusual behavior/confusion/hallucinations promptly, especially in children. This does not replace annual influenza vaccination. Store below 30°C in the original blister (per SFDA storage).

Monitoring Requirements

No routine laboratory monitoring is required; monitor clinically for neuropsychiatric symptoms/abnormal behavior (especially in children/adolescents) and for clinical response/complications of influenza.

Pharmacology

Mechanism of Action

Neuraminidase inhibitor: inhibits influenza A and B neuraminidase, preventing release of progeny virions from infected cells and limiting viral spread.

Onset of Action

Symptom improvement is typically seen within 24-48 hours after starting therapy when initiated early (ideally within 48 hours of symptom onset).

Duration of Effect

Clinical antiviral effect is maintained with continued dosing: twice daily for treatment (typically 5 days) and once daily for prophylaxis for the prescribed duration.

Half-Life

Oseltamivir (prodrug) half-life ~1-3 hours; active metabolite (oseltamivir carboxylate) half-life ~6-10 hours.

Bioavailability

Approximately 80% systemic availability as the active metabolite (oseltamivir carboxylate) after oral administration.

Metabolism

Oseltamivir (prodrug) is rapidly hydrolyzed by hepatic (and intestinal) esterases to the active metabolite oseltamivir carboxylate; it is not meaningfully metabolized by CYP450 enzymes.

Excretion

Primarily renal: >90% (often cited ~99%) of the active metabolite is excreted in urine largely unchanged via filtration and tubular secretion.

Product Information

Available Dosage Forms

Capsule, Powder for oral suspension.

Composition per Dose

Each capsule: 75mg oseltamivir (as oseltamivir phosphate)

Generic Availability

Yes

OTC Alternatives

No OTC alternative

Viral Target

Influenza

Reviewed by Al Mujtama Pharmacy Medical Review Team. Last reviewed 11-08-2026