What are the contraindications for Tamiflu (oseltamivir)?

Tamiflu (Oseltamivir) Contraindications

Tamiflu (oseltamivir) is contraindicated in patients with known serious hypersensitivity to oseltamivir or any component of the product. 1

Primary Contraindication

• Severe allergic reactions to oseltamivir or any components of the formulation, which may include:
  • Anaphylaxis 1
  • Serious skin reactions including toxic epidermal necrolysis 1
  • Stevens-Johnson Syndrome 1
  • Erythema multiforme 1

Special Considerations for Use

Renal Impairment

• Dose adjustment required for patients with renal insufficiency based on creatinine clearance 2
• For treatment of patients with creatinine clearance 10-30 mL/min: 75 mg once daily for 5 days 2
• For chemoprophylaxis of patients with creatinine clearance 10-30 mL/min: 30 mg once daily for 10 days after exposure or 75 mg once every other day for 10 days after exposure (5 doses) 2

Age-Specific Considerations

• Approved for use in children as young as 2 weeks of age 2
• Preterm infants require lower weight-based dosing due to immature renal function 2
• Dosing for preterm infants based on postmenstrual age (gestational age + chronological age) 2

Drug Interactions

• Live attenuated influenza vaccine (LAIV): Receipt of specific antivirals (including oseltamivir) within 48 hours before vaccination should be avoided; these antiviral drugs should not be used for 14 days after LAIV vaccination 2
• Potential for competitive inhibition of excretion by the renal tubular epithelial cell anionic transporter 3
• Limited potential for adverse interactions with other drugs 3

Common Adverse Events

• Gastrointestinal effects:

  • Nausea 2
  • Vomiting 2
  • Diarrhea (particularly in children <1 year of age) 2

• Other adverse events:

  • Headache 2
  • Skin reactions 2
  • Potential psychiatric adverse events (dose-related) 4, 5

Clinical Pearls

• Administration with meals may improve gastrointestinal tolerability 2
• For infants younger than 1 year, an appropriate measuring device such as a 3-mL or 5-mL oral syringe should be used instead of the syringe supplied with the medication 2
• Oseltamivir is available as capsules (30-mg, 45-mg, and 75-mg) and as a powder for oral suspension (6 mg/mL) 2
• Treatment should be initiated within 48 hours of symptom onset for maximum effectiveness 2
• While not a contraindication, the risk-benefit ratio should be carefully considered in pregnant women, although benefits of therapy are likely to outweigh possible risks 5

Remember that while oseltamivir has specific contraindications related to hypersensitivity, appropriate dose adjustments for renal function and age are essential for safe use of this medication across different patient populations.