amphotéricine

Amphotericin B, also known as amphotéricine B in French, is a polyene antifungal antibiotic produced by Streptomyces nodosus. It is used to treat severe, systemic fungal infections and is often reserved for life-threatening cases or infections resistant to other antifungals.

Amphotericin B binds ergosterol in fungal cell membranes, creating pores that increase permeability and cause leakage of intracellular contents, leading to cell death. The drug can also bind to cholesterol in human membranes, contributing to toxicity.

It is poorly absorbed from the gastrointestinal tract and is given by intravenous infusion. It distributes widely, including into cerebrospinal fluid, especially during meningitis. Conventional amphotericin B deoxycholate is linked to higher nephrotoxicity, whereas lipid formulations reduce kidney toxicity but cost more.

It is used for cryptococcal meningitis, histoplasmosis, blastomycosis, mucormycosis, and other invasive fungal diseases. It is sometimes combined with flucytosine for cryptococcal meningitis and is used as salvage therapy for aspergillosis when other antifungals fail.

Major limitations include nephrotoxicity, electrolyte disturbances (hypokalemia, hypomagnesemia), and anemia, along with fever and chills during infusions. Monitoring of renal function, electrolytes, and blood counts is required; premedication and slower infusion rates may help reduce reactions.

Discovered in the 1950s, amphotericin B remains a mainstay of therapy for severe fungal infections, with lipid formulations introduced in the late 20th century to improve safety and tolerability.