What is the most common side effect associated with IV amphotericin B use?

• A. Hepatotoxicity
• B. Nephrotoxicity
• C. Neurotoxicity
• D. Cardiotoxicity

Answer: (B)

Nephrotoxicity is the most common adverse effect of intravenous amphotericin B. The drug can interact with cholesterol in human cell membranes, including kidney cells, leading to direct tubular toxicity and afferent arteriolar vasoconstriction. This combination reduces the glomerular filtration rate and causes electrolyte losses (notably potassium and magnesium), making kidney injury the dose-limiting toxicity of amphotericin B.

In contrast, while liver toxicity, neurotoxicity, or cardiotoxicity can occur, they are far less common with standard IV use. Strategies to lessen nephrotoxicity include pre- and post-infusion hydration, avoiding other nephrotoxins, and using liposomal or lipid formulations when possible, which are associated with lower risk to the kidneys. Monitoring renal function and electrolytes is essential during therapy.