Drug Kinetics, Dosing, and Renal Toxicity in Older Adults

Abstract

Drug-induced nephrotoxicity may cause up to 20 % of community- and hospital-acquired episodes of acute kidney injury (AKI) with an incidence of approximately 30–40 % among older adults. About half of all medications (or active metabolites thereof) are eliminated by the kidneys. Since half of older patients have reduced renal function, this is important for drug dosage, as in these patients drugs will be slower eliminated and have the potential to accumulate.

Before initiation of therapy, assessment of baseline renal function in older patients is of importance. During therapy, therapeutic drug monitoring, monitoring of renal function, as well as avoidance of nephrotoxic drug combinations are advised.

Changes in pharmacodynamics justify the common medication rule in older patients – “start low+go slow” – especially for drugs that act on the central nervous system and cardiovascular drugs; however, in the case of anti-infective and anticancer therapy, the rule should be “hit hard+go fast” to produce the target effect immediately also in older patients. For specific “hands-on” recommendations relating to drug dosage or drug choice for patients with reduced renal function, several website are recommended.