Oseltamivir

Administration

  • Type: Antiviral
  • Routes of Administration: Oral
  • Common Trade Names: Tamiflu

Adult Dosing

Influenza

  • 75mg PO BID x 5 days

Pediatric Dosing

Influenza

  • Age <1 year: 3mg/kg PO BID x 5 days
  • <15kg: 30mg PO BID x 5 days
  • 15-23kg: 45mg PO BID x 5 days
  • 24-40kg: 60mg PO BID x5d
  • Adult: 75mg PO BID x 5 days

Special Populations

  • Pregnancy Rating: Category C
  • Lactation risk: Low concentrations of oseltamivir seen in breast milk; levels are unlikely to lead to toxicity in a breast-fed infant. The manufacturer recommends that caution be used if administered to a nursing woman.
  • High Risk for Complications and Recommended for Treatment per CDC:
    • Children < 2 yo
    • Adults > 65 yo
    • Chronic Pulmonary Disease including Asthma
    • Cardiovascular disease (excluding hypertension only)
    • Renal, hepatic, hematological, and metabolic disorders (including sickle cell, diabetes)
    • Neurological and Neurodevelopmental disorders (brain disorders, spinal cord, peripheral nerve disorders, cerebreal palsy, epilepsy, stroke, MR, developmental delay, muscular dystrophy)
    • Immunosuppressed including on HAART
    • Pregnant or Postpartum (2 weeks after delivery)
    • <19 yo on long term aspirin
    • American Indians/Alaskan natives
    • Morbid Obesity (BMI >= 40)
    • Nursing home or chronic care facility residents.

Renal Dosing

  • CrCl >30 to 60 mL/minute: 30mg BID for 5 days
  • CrCl >10 to 30 mL/minute: 30mg qday for 5 days
  • ESRD not undergoing dialysis: Use is not recommended (efficacy in ESRD has not been established.)

Hepatic Dosing

  • efficacy in hepatic impairment has not been established

Contraindications

  • Allergy to class/drug

Adverse Reactions

Serious

  • dysrhythmia
  • erythema multiforme/TEN/SJS
  • GI bleed, hepatitis
  • seizure, delirium

Common

  • abdominal pain, nausea/vomiting

Pharmacology

  • Half-life:
  • Metabolism:
  • Excretion:

Mechanism of Action

  • inhibits viral neuroaminidase→ interferes with viral particle release

Comments

  • Influenza
    • Shortens duration of illness by 16.8 hrs while NNTH (number needed to harm) was 28 in regards to causing nausea and vomiting, HA, and renal and psych syndromes[1]
    • Greatest benefit if within 48hrs of symptom onset[2]
      • However, may be beneficial up to 4-5 days, including in pregnant patients
      • Early treatment of hospitalized patients can reduce death

See Also

References

  1. Jefferson T, et al. Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments. BMJ. 2014; 348:g2545.
  2. CDC Guidelines. 2015-2016. http://www.cdc.gov/flu/professionals/antivirals/summary-clinicians.htm