Acyclovir (topical, oral and parentral }

Amphotericin B   

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mechanism of actions

Tightly and selectively bind to ergosterol in the plasma membranes ➔ formation of artificial pores which disrupt membrane function. ✓ Either fungicidal or fungistatic depending on the concentration of the drug (small dose: static, large dose: cidal).

Kinetics

✓ Poorly absorbed from the GIT, so usually taken as I.V infusion. ✓ Widely distributed to body tissues, except the CNS (but extremely effective in fungal meningitis (cryptococcal meningitis) when combined with 5-FC).

Uses

✓ It is DOC for treatment of severe systemic mycosis (Aspergillus, Candida or Cryptococcus) ✓ Liposomal amphotericin B ➔ new lipid formulation of amphotericin B which is much more effective with less side effects but very expensive.

side sffects

1) Infusion related side effects ➔ Fever, dyspnea, histamine release ➔ Nausea and vomiting and hypotension (can be overcome by antipyretic and antihistaminics prior to infusion). 2) Drug related side effects: Nephrotoxicity & hypokalemia ➔ requiring K+ supplement