Why does a patient with impaired renal function typically require a lower dose of a drug primarily eliminated by the kidneys?

💡 Explanation

Reduced renal function impairs the glomerular filtration and tubular secretion, which directly decreases drug clearance because these processes are critical for eliminating the drug. Therefore, a lower dose prevents drug accumulation and toxicity, rather than changes in hepatic metabolism, distribution volume, or bioavailability.

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