The rise in blood levels of medications in the elderly is most likely due to which organ issue?

• A. Renal dysfunction
• B. Renal insufficiency
• C. Liver failure
• D. Heart failure

Answer: (B)

In older adults, the kidneys often don’t filter and excrete drugs as effectively as before. When renal clearance declines, a drug stays in the bloodstream longer, so its concentration rises and the drug can accumulate to levels that can cause toxicity. This makes renal insufficiency the most direct reason for higher medication levels in the elderly, since it specifically reflects reduced kidney function and clearance.

Renal dysfunction is a broader term that could include varying degrees of impairment, but it doesn’t pinpoint the reduced clearance as clearly as renal insufficiency. Liver failure would affect metabolism more than elimination, and heart failure can alter distribution, but neither explains the common, direct cause of increased blood levels seen with aging as clearly as diminished renal clearance does.