Abacavir (Ziagen)

Pharmacology

  • Nucleoside Reverse Transcriptase Inhibitor

Adverse Effects

General Adverse Effects

Abacavir Hypersensitivity Reaction

  • Epidemiology
    • Relationship to Abacavir Dosing Frequency
      • Hypersensitivity reaction may be more severe with once daily dosing
    • Risk Factors
      • HLA B*5701 -> can screen for this prior to abacavir administration
    • Temporal Relationship to Abacavir Administration
      • During Abacavir Therapy
        • Occurs within few days-6 weeks (median = 11 days) after start of therapy
        • Symptoms usually worsen with continuation of therapy
      • After Re-Introduction of Abacavir
        • Occurs within hours of re-introduction after an interruption in therapy
        • Particularly severe reactions can occur with re-challenge in patients with a previous hypersensitivity reaction
  • Physiology
    • Hypersensitivity (immune)-mediated reaction
  • Clinical
  • Treatment
    • Immediate Withdrawal of Drug: avoid re-challenge with drug in the future if hypersensitivity reaction occurs
    • Supportive Care
  • Prognosis
    • Death: may occur in severe cases

References

  • HLA-B*5701 Screening for Hypersensitivity to Abacavir. ┬áN Engl J Med 2008; 358:568-579