Antifungal Drugs

Antifungal Drugs

1. Introduction & importance

• Fungi are eukaryotes, so drugs that kill the pathogen without harming the human host are inherently hard to design — selective targets are few (membrane ergosterol, the deaminating capacity for cytosine, and the glucan/chitin cell wall) (G&G 14e Ch.61, p.1193).
• The incidence of life-threatening (invasive) fungal infection has risen sharply with the expanding immunocompromised population: haematologic/solid-organ transplant recipients, cancer chemotherapy, immunosuppressive drugs, indwelling catheters/implants, and HIV–AIDS (G&G 14e Ch.61, p.1193; KDT 8e Ch.58, p.838; Katzung 16e Ch.48, p.898).
• Much of the rising burden is iatrogenic — broad-spectrum antibiotics, corticosteroids and anticancer/immunosuppressant drugs break down host defences and let saprophytic fungi invade living tissue (KDT 8e Ch.58, p.838).
• Despite the modern armamentarium, mortality of invasive fungal disease remains unacceptably high (G&G 14e Ch.61, p.1193).
• Therapeutically the antifungals split into: (a) systemic drugs for deeply invasive mycoses, (b) oral systemic drugs for mucocutaneous infections, and (c) topical drugs for mucocutaneous/superficial infections (Katzung 16e Ch.48, p.898).