AZOLES

Structure/Class
  1. Imidazoles – ketoconazole, miconazole, clotrimoxazole
  2. Triazoles – fluconazole, voriconazole
Pharmacodynamics
  1. Inhibits fungal CYP 450, therefore reducing ergosterol synthesis.
    • Specificity comes from the fact that azoles have greater affinity for fungal CYP than human CYP.
    • Imidazoles are less selective and hence more toxic.
  2. Spectrum of activity
    • Broad – candida, mycoses, aspergillus
  3. Toxicity
    • Minor GI upset
    • Rarely, clinically significant hepatitis.
Pharmacokinetics
  1. Fluconazole has interesting pharmacokinetics
    • Can be given PO/IV (good bioavailability)
    • It has high CSF penetration and can be used un fungal meningitis (other anti-fungals do not)
    • It is an inhibitor of CYP 450 enzyme, and has drug interactions as such.
    • Widest therapeutic index.