Oseltamivir (Tamiflu)
Oral neuraminidase inhibitor prodrug for influenza A and B treatment and prophylaxis. Rapidly converted by hepatic esterases to active oseltamivir carboxylate, which competitively inhibits influenza neuraminidase, blocking viral release from infected cells. Minimal CYP450 involvement — unlike most drug interactions. Renal excretion of active carboxylate unchanged (dose reduce in CKD; CrCl <60: 30 mg bid; <30: 30 mg daily). Treatment must start within 48h of symptom onset. Gained prominence during 2009 H1N1 pandemic and is stockpiled globally for pandemic preparedness. Neuropsychiatric adverse events in adolescents debated.
Projected serum levels — 75 mg, twice daily
Maintenance schedule: 75 mg twice daily (oral).
Loading schedule: 125 mg on day 1, then 75 mg twice daily — reaching therapeutic levels sooner.
Modeled steady state after ~2 days: peak ≈ 73.2 mg, trough ≈ 38.1 mg body load. Population-based estimate over 15 days for a 75 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.
Key facts
- Category
- Antiviral
- Route modeled
- Oral
- Model confidence
- inferred
- Half-life
- 8 h
- Common dose
- 75 mg
- Suggested maximum
- 150 mg/day
- Reference dose range
- 30–150 mg (single dose)
- Suggested cadence
- twice daily
- Validated against
- 75 mg oral — Cmax 0.35 mg/L at 3.5 h
Documented interactions
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moderate
Dolutegravir (DTG / Tivicay) + Oseltamivir (Tamiflu)
Dolutegravir (DTG / Tivicay) inhibitor of OCT2 may alter Oseltamivir (Tamiflu) absorption / distribution
-
moderate
Trimethoprim/Sulfamethoxazole (Bactrim) + Oseltamivir (Tamiflu)
Trimethoprim/Sulfamethoxazole (Bactrim) inhibitor of OCT2 may alter Oseltamivir (Tamiflu) absorption / distribution
Serum checks 2 modeled interaction pairings for oseltamivir (tamiflu) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.
Research behind this entry
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Oseltamivir treatment for influenza in adults: a meta-analysis of randomised controlled trials
Individual patient data meta-analysis of 9 RCTs (n=4328) showing oseltamivir reduces time to symptom alleviation by ~21 hours (from 122.7h to 97.5h), reduces lower respiratory tract infections requiring antibiotics by…
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Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children
Controversial Cochrane review questioning magnitude of oseltamivir clinical benefit, finding treatment reduces symptom duration by ~17h, but finding insufficient evidence of reduction in complications or…
2 published studies referenced in the app, each with a plain-language summary.