Mechanisms of Action Flashcards
Reduce hyperkeratinization.
Keratolytics
Reverse abnormal keratinization.
Retinoids
Reduce microbial colonization and decrease inflammatory response.
Antibiotics
Inhibits cholinesterase.
Malathion (Ovide)
Vasoconstrictor effect.
Topical corticosteroids
Inhibits phosphatase activity, resulting in inhibition of T-cell activation.
Calcineurin inhibitors
Bind to sterols in the cell membrane of the fungus, causing increased membrane permeability and loss of intracellular contents.
Polyene antifungals
Binds to ergosterol in fungi cell wall.
Amphotericin B
Reduce ergosterol synthesis by inhibition of fungal cytochrome P450.
Triazole antifungals
Reduce ergosterol synthesis by inhibition of fungal cytochrome P450, but less selective between human and fungal sterols, so more toxic.
Imidazole antifungals
Inhibit the synthesis of ergosterol by
inhibiting squalene epoxidase.
Allylamine antifungals
Inhibits epoxidation of squalene in fungi, so is toxic to fungi. Also reduces ergosterol and prevents synthesis of fungal
cell membrane.
Terbinafine (Lamisil)
Inhibits fungal cell mitosis at metaphase by
interfering with cells mitotic spindle structure.
Griseofulvin
Acts by chelating polyvalent cations (Fe+3) or (Al+3). Inhibits enzymes responsible for the breakdown of peroxidises within fungal cells.
Ciclopirox (Pen-Lac, Loprox)
Mechanism of action unknown but may block
enzymes involved in growth of epithelial tissue.
Selenium sulfide
These inhibit viral DNA synthesis.
Nucleoside analogues
Inhibits DNA synthesis and viral replication. Competes with deoxyguanosine triphosphate binding. DNA templates into irreversible complexes. Causes chain termination following incorporation of viral DNA.
Acyclovir family
Converted by body to acyclovir after oral administration via first pass.
Valacyclovir