Which of the following is true about Amphotericin B?

• A. It inhibits ergosterol synthesis
• B. It binds cholesterol in human cell membranes
• C. It forms pores by binding ergosterol
• D. It inhibits DNA replication

Answer: (C)

Amphotericin B works by binding to ergosterol in fungal cell membranes and forming pores. This creates channels that let essential ions and small molecules leak out, leading to fungal cell death. The selectivity comes from ergosterol being more prevalent in fungal membranes than cholesterol in human membranes, so the drug preferentially disrupts fungal cells. It’s true that Amphotericin B can interact with cholesterol and contribute to toxicity, but the characteristic and therapeutic action is pore formation due to ergosterol binding. The other statements describe different mechanisms: inhibiting ergosterol synthesis is typical of azole antifungals, and inhibiting DNA replication is associated with drugs like flucytosine.