Why can amphotericin B cause toxic effects in humans?

Amphotericin B causes toxic effects in humans primarily because of its mechanism of action. As a polyene antifungal drug, it works by binding to ergosterol, a steroid found in fungal cell membranes, to form channels that cause the leakage of vital cytoplasmic components and cell death.12

The drug's toxicity arises because cholesterol, which is present in human cell membranes, is structurally similar to ergosterol. Consequently, the drug can interact with human cells, leading to side effects such as fever, chills, hypotension, and nausea. Most patients also experience some degree of kidney toxicity, though renal function typically improves once therapy is completed. To mitigate these risks, medical professionals may utilize lipid-based formulations, which are designed to reduce toxicity while maintaining the drug's effectiveness against serious fungal infections.1