antifungální

Antifungální, or antifungal agents, are medicines used to treat fungal infections in humans and animals. They can be natural, semisynthetic, or synthetic and may be used systemically for invasive infections or topically for skin and mucosal infections. Choice depends on the pathogen, infection site, patient factors, and potential drug interactions.

Major classes and actions include: polyenes (amphotericin B, nystatin) that disrupt membranes by binding ergosterol; azoles (fluconazole, itraconazole, voriconazole, posaconazole) that inhibit ergosterol synthesis; allylamines (terbinafine) that block squalene epoxidase; echinocandins (caspofungin, micafungin, anidulafungin) that inhibit β-1,3-glucan synthesis in the cell wall; antimetabolites (flucytosine) that disrupt nucleic acid synthesis. Griseofulvin and tavaborole are used mainly for dermatophyte infections. These drugs differ in spectrum, tissue penetration, and safety profiles.

Common indications include invasive candidiasis, cryptococcal meningitis, aspergillosis, and dermatophyte infections. Pharmacokinetics vary; some agents have excellent oral bioavailability or central nervous system penetration, while others are primarily topical. Treatment choice depends on the organism, site of infection, and patient factors, with adjustments for drug interactions and pregnancy when applicable.

Adverse effects and resistance pose ongoing challenges. Amphotericin B can cause nephrotoxicity and infusion reactions; azoles may cause hepatotoxicity and drug interactions; echinocandins are generally well tolerated but can elevate liver enzymes. Resistance mechanisms include target modification and efflux pumps, underlining the importance of susceptibility testing and prudent use.