Antifungális

Antifungális, or antifungal agents, are medicines used to treat fungal infections in humans and animals. They work by killing fungi (fungicidal) or inhibiting their growth (fungistatic), and they can be applied topically, taken orally, or given by injection depending on the infection.

Major drug classes include polyenes (amphotericin B, nystatin), which bind ergosterol in fungal membranes; azoles (fluconazole, itraconazole, voriconazole, posaconazole, isavuconazole) which inhibit the synthesis of ergosterol; echinocandins (caspofungin, micafungin, anidulafungin) which inhibit beta-1,3-D-glucan synthesis in the cell wall; allylamines (terbinafine) which inhibit squalene epoxidase; the antimetabolite flucytosine; and others such as griseofulvin. Many antifungals are derived from natural products produced by fungi or bacteria.

Spectrum and use vary by agent. Amphotericin B and voriconazole cover a broad range of fungi, including many yeasts and molds, and are used for serious systemic infections. Fluconazole is effective against most Candida species and Cryptococcus; itraconazole and posaconazole extend activity to dimorphic fungi and certain molds; echinocandins are especially active against Candida and some Aspergillus species. Dermatophyte infections are commonly treated with topical azoles or allylamines. Flucytosine is primarily used in combination therapy for cryptococcal meningitis.

Administration and safety considerations vary by drug. Systemic infections require systemic therapy; nephrotoxicity is a concern with amphotericin B, while azoles can cause hepatotoxicity and interact with many other drugs. Echinocandins are generally well tolerated but require intravenous administration. Resistance can arise through target mutations or drug efflux, underscoring the importance of appropriate indications, dosing, and duration.