GMS6540: ANTIFUNGALS AND ANTIPARASITICS EXAM
QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS
VERIFIED
antifungal drugs
-fungal cell wall made up of beta-glucans
-beta-glucan synthase makes precursor of the cell wall
-ergosterol in membranes (instead of cholesterol)
-different drugs target different parts
systemic antifungal drugs
-amphotericin B
-caspofungin
-flucytosine
-itraconazole
superficial antifungal drugs
-nystatin
-miconazole
-terbinafine
Amphotericin B
-systemic antifungal
-binds selectively to ergosterol (structurally related to cholesterol)
-disrupts fungal cell membrane function
-used for MOST systemic fungal infections
, -broad spectrum of antifungal activity
-also used for treatment of leishmaniasis
-NOT absorbed orally; MUST be given by IV
-adverse effects = nephrotoxicity (lipid formulations have reduced renal toxicity)
Echinocandins (Caspofungin)
-Caspofungin
-systemic antifungal
-inhibits synthesis of cell wall polysaccharides
-used as an alternate therapy for serious systemic fungal infections
-POOR oral absorption-- given by IV
Flucytosine
-systemic antifungal
-prodrug = selectively activated to 5-fluorouracil by fungal-specific enzyme (cytosine
deaminase)
-blocks DNA synthesis by inhibiting thymidylate synthetase
-synergistic combination with amphotericin B
-adverse effects = enterocolitis, high prolonged serum levels may cause bone marrow
suppression (mechanism?)
Itraconazole
-azole antifungals
-systemic antifungal
-inhibits cytochrome P450 mediated synthesis of ergosterol by fungi
-extended to broad spectrum
QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS
VERIFIED
antifungal drugs
-fungal cell wall made up of beta-glucans
-beta-glucan synthase makes precursor of the cell wall
-ergosterol in membranes (instead of cholesterol)
-different drugs target different parts
systemic antifungal drugs
-amphotericin B
-caspofungin
-flucytosine
-itraconazole
superficial antifungal drugs
-nystatin
-miconazole
-terbinafine
Amphotericin B
-systemic antifungal
-binds selectively to ergosterol (structurally related to cholesterol)
-disrupts fungal cell membrane function
-used for MOST systemic fungal infections
, -broad spectrum of antifungal activity
-also used for treatment of leishmaniasis
-NOT absorbed orally; MUST be given by IV
-adverse effects = nephrotoxicity (lipid formulations have reduced renal toxicity)
Echinocandins (Caspofungin)
-Caspofungin
-systemic antifungal
-inhibits synthesis of cell wall polysaccharides
-used as an alternate therapy for serious systemic fungal infections
-POOR oral absorption-- given by IV
Flucytosine
-systemic antifungal
-prodrug = selectively activated to 5-fluorouracil by fungal-specific enzyme (cytosine
deaminase)
-blocks DNA synthesis by inhibiting thymidylate synthetase
-synergistic combination with amphotericin B
-adverse effects = enterocolitis, high prolonged serum levels may cause bone marrow
suppression (mechanism?)
Itraconazole
-azole antifungals
-systemic antifungal
-inhibits cytochrome P450 mediated synthesis of ergosterol by fungi
-extended to broad spectrum
