Tamiflu drug interactions: a practical overview
Drug interactions are the single biggest cause of preventable medication problems. Tamiflu (Oseltamivir) interacts to varying degrees with several classes of medication and with a smaller list of foods. This page summarises the practically important ones at 30mg, 45mg, 75mg, framed for a real-world prescription review rather than an exhaustive PDF list.
High-priority interactions for Tamiflu
For Oseltamivir, the most clinically relevant interactions are typically with strong CYP3A4 inhibitors and inducers, with cardiovascular medications (notably nitrates for several Antiviral Medications agents), with central nervous system depressants, and with medications affecting blood pressure or heart rate. Oseltamivir is a prodrug rapidly hydrolysed by hepatic esterases to the active metabolite oseltamivir carboxylate, which selectively inhibits the neuraminidase enzyme on the surface of influenza A and…
Working with the pharmacist
A pharmacist review of all current medications is the practical safeguard against unintended interactions with Tamiflu. According to the prescribing information for Oseltamivir, the full medication list — prescription, OTC, supplements and recreational substances — should be reviewed before starting and at every dose change at 30mg, 45mg, 75mg.
Frequently asked questions
What's the most important Tamiflu interaction to know? ▾
For most Antiviral Medications medications, the highest-priority interaction is with nitrate medications used for chest pain — this combination is often a hard contraindication. After that, strong CYP3A4 inhibitors (some antifungals, macrolides) are the next concern at routine 30mg, 45mg, 75mg doses.
Do I need to tell the pharmacist about supplements? ▾
Yes. Supplements and herbal products can interact with Tamiflu in ways that prescription drug-drug interaction databases miss. The pharmacist needs the complete picture — including supplements like St John's Wort, grapefruit-containing products and high-dose vitamins — to flag risks at 30mg, 45mg, 75mg.
More on Tamiflu
- With alcoholTamiflu and alcohol — is it safe to drink?
- With foodShould Tamiflu be taken with food?
- Side effectsTamiflu side effects: common, rare and warning signs
- Dosage guideTamiflu dosage guide: how much to take and when
- OnsetHow fast does Tamiflu start working?
- DurationHow long does Tamiflu last?
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.