What are the contraindications to Tamiflu (oseltamivir)?

Contraindications to Tamiflu (Oseltamivir)

The only absolute contraindication to Tamiflu is known serious hypersensitivity to oseltamivir or any component of the product, including prior severe allergic reactions such as anaphylaxis, toxic epidermal necrolysis, Stevens-Johnson Syndrome, or erythema multiforme. 1

Absolute Contraindication

• Serious hypersensitivity reactions: Patients with documented severe allergic reactions to oseltamivir or any formulation component must not receive this medication. 1
• Severe reactions that constitute contraindications include:
  • Anaphylaxis 1
  • Toxic epidermal necrolysis 1
  • Stevens-Johnson Syndrome 1
  • Erythema multiforme 1

Important Clinical Context: What Is NOT a Contraindication

Understanding what does not contraindicate oseltamivir is equally critical to avoid withholding beneficial therapy:

Age Is Not a Contraindication

• Oseltamivir is FDA-approved for treatment starting at 2 weeks of age and can be used from birth (including preterm infants) when benefits outweigh risks. 2
• Prophylaxis is approved starting at 1 year of age, though off-label use in infants 3-11 months is supported when clinically indicated. 2
• Extremely preterm infants (<28 weeks gestational age) require specialist consultation but are not absolutely contraindicated. 2

Pregnancy and Lactation Are Not Contraindications

• Oseltamivir can be used during pregnancy with no contraindication existing. 2
• The American Academy of Pediatrics supports use in pregnant women when influenza is suspected or confirmed. 2

Common Medical Conditions Are Not Contraindications

• Patients with asthma, chronic pulmonary disease, cardiovascular disease, diabetes, and immunodeficiency can safely receive oseltamivir. 2
• These conditions actually represent indications for treatment rather than contraindications, as they increase complication risk. 2

Renal Impairment Is Not a Contraindication

• Renal dysfunction requires dose adjustment, not avoidance. 2
• For creatinine clearance 10-30 mL/min: reduce treatment dose to 75 mg once daily (instead of twice daily) for 5 days. 2
• For prophylaxis in renal impairment: 30 mg once daily OR 75 mg every other day for 10 days. 2
• The drug is eliminated renally, and failure to adjust doses in renal impairment can lead to toxicity, but this is a dosing consideration, not a contraindication. 3

Mild Illness or Fever Alone Are Not Contraindications

• The American Academy of Pediatrics explicitly advises against withholding oseltamivir due to mild illness or fever alone. 2
• Minor febrile illnesses do not contraindicate therapy. 2

Critical Timing Consideration (Not a Contraindication)

• While oseltamivir is most effective when initiated within 48 hours of symptom onset, delayed presentation beyond 48 hours is not a contraindication in high-risk patients or those with severe illness. 2
• Treatment should still be considered in hospitalized patients or those at high risk for complications even if presenting after 48 hours. 2

Drug Interaction Consideration (Not a Contraindication)

• Live attenuated influenza vaccine (LAIV): The CDC recommends avoiding LAIV within 48 hours before oseltamivir use, and not using oseltamivir for 14 days after LAIV vaccination, as the antiviral may interfere with vaccine efficacy. 2
• This is a timing consideration for vaccine effectiveness, not an absolute contraindication to oseltamivir therapy. 2
• Inactivated influenza vaccine has no such interaction. 2

Common Pitfalls to Avoid

• Do not confuse adverse effects with contraindications: Gastrointestinal symptoms (nausea, vomiting, diarrhea) occur in 10-15% of patients but are mild, transient, and can be minimized by taking oseltamivir with food. 2, 1
• Do not withhold therapy in infants due to age concerns: With appropriate postmenstrual age-based dosing for preterm infants, the safety profile is comparable to older children. 2
• Do not avoid oseltamivir in patients with prior mild gastrointestinal upset: Only approximately 1% of patients discontinue therapy due to GI side effects. 2
• Do not confuse dose adjustment requirements with contraindications: Renal impairment, advanced age, and young age all require dosing modifications but do not preclude use. 2