Can Tamiflu and Augmentin Be Given Together?
Yes, Tamiflu (oseltamivir) and Augmentin (amoxicillin-clavulanate) can be safely given together without clinically significant drug interactions.
Drug Interaction Profile
- No clinically relevant pharmacokinetic interactions occur when oseltamivir is coadministered with amoxicillin, as explicitly stated in FDA labeling 1
- Oseltamivir is extensively converted to its active form by esterases (not P450 enzymes), and neither oseltamivir nor its active metabolite are good substrates for P450 mixed-function oxidases or glucuronyl transferases 1
- The low protein binding of both oseltamivir and its active metabolite suggests minimal probability of drug displacement interactions 1
Clinical Context for Combined Use
This combination is commonly used in clinical practice when:
- Bacterial superinfection complicates influenza - Augmentin provides coverage for beta-lactamase-producing respiratory pathogens including Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae 2, 3
- Concurrent bacterial and viral respiratory infections are suspected or confirmed
- Secondary bacterial pneumonia or sinusitis develops during or after influenza illness
Administration Considerations
- Both medications can be taken with food to improve gastrointestinal tolerability 4, 5
- Taking oseltamivir with meals specifically reduces nausea and vomiting, which are common adverse effects 4
- Gastrointestinal side effects (nausea, vomiting, diarrhea) may be additive when both drugs are used together, as both can cause GI upset 4, 6
Important Timing Considerations
- Oseltamivir must be initiated within 48 hours of influenza symptom onset for maximum effectiveness 4, 5
- Standard oseltamivir treatment duration is 5 days at 75 mg twice daily for adults 4, 5
- Augmentin dosing and duration depend on the specific bacterial infection being treated 2, 3
Common Pitfall to Avoid
The main clinical concern is not a drug interaction but rather ensuring appropriate indication for each medication. Avoid prescribing Augmentin for uncomplicated influenza without evidence of bacterial co-infection, as this contributes to antimicrobial resistance without clinical benefit.