What is the potential consequence of renal impairment on drug therapy?

Renal impairment significantly affects drug therapy, primarily through its impact on drug excretion. The kidneys play a crucial role in eliminating many medications and their metabolites from the body. When renal function is compromised, the ability to properly excrete these substances decreases, leading to a buildup of the drug in the bloodstream. This increased concentration can elevate the risk of adverse effects and toxicity, especially with medications that have a narrow therapeutic index, where the margin between effectiveness and toxicity is very small.

In patients with renal impairment, careful dosage adjustments and monitoring may be necessary to ensure safe and effective pharmacotherapy. This highlights the importance of assessing renal function prior to initiating or continuing therapy for medications primarily cleared by the kidneys.