Block 9- Week 4 Flashcards
Clotrimazole
(Fungal Ianosine demethylase inhibitor )
Inhibits yeast 14-alpha demethylase (cytochrome P450enzyme) that converts lanosterol to ergosterol - Important component of fungal cell membrane - inhibition leads to incr membrane permeability and possible disruption of membrane bound enzymes.
Fluconazole
Fungal Ianosine demethylase inhibitor
Synthetic anti fungal - treats vaginal candidasis
- same mechanism of action as Clotrimazole.
Nystatin
Anti fungal effective against a variety of yeasts and yeast like fungi incl Candida albicans , etc
Bonds to ergosterol in fungal cell membranes causing formation of pores in the membrane leading to potassium and other cellular constituents leaking causing cell death
Amphotericin
Ionophore
Same mechanism of action as Nystatin
Pyrimethamine
Folate antagonist
Used in treatment of Malaria - anti parasitic compound inhibits dihydrofolate reductase of plasmodia and blocks biosynthesis of purines and pyrimidines which are essential for DNA synthesis and cell multiplication highly effective against toxoplasma Gondii
Quinine
Haem polymerase inhibitor
Inhibits the parasites ability (plasmodium falciparum malaria )to break down and digest hemoglobin .which causes parasite to starve or build up toxic levels of partially degraded hemoglobin in itself .
Arthemether
Peroxide anti malarial
Interaction of the peroxide containing drug with heme in the parasite food vacuole results in the formation of a range of potentially toxic oxygen and carbon-centred radicals
Reduces number of malarial parasites
3 major classes of antifungals
- Polyene
- Azoles
- Echocandins
Polyene
Bind with ergosterol and form pores chasing leakage -> cells die
Amphotericin
Azoles
Inhibit lanosterol demethylase needed to convert lanosterol to ergosterol -> disrupts membrane structure
Fluconazole
Voriconazole
Echocandins
Inhibit synthesis of glucan in the cell wall via glucan synthase
Caspofungin
