Pharmacology and the Kidney

Abstract

The kidney plays an important role in the handling of drugs in the body; therefore, patients with renal impairment will invariably require different dosage regimes to those with normal renal function. Unfortunately, there are no absolute guidelines on how to adjust doses in renal impairment, and pharmaceutical company literature often excludes patients with renal impairment in the dosage guidelines. Where information can be found, the advice may not be specific and different texts may give different advice. Therefore, it is important to have an understanding of the potential effects of renal impairment on the pharmacodynamic and pharmacokinetic properties of a drug so that appropriate dosing decisions can be made. Although a reduced GFR is the primary reason for reduced excretion of drugs in renal failure, absorption, distribution, protein binding, metabolism and pharmacodynamics are all relevant. Furthermore, the kidney can also be affected by a variety of drugs resulting in both acute and chronic kidney injury. A variety of mechanisms are involved and ascertaining causality is not always possible, but given the impact of AKI and CKD on patients, it is critical to have a high index of suspicion of drug-induced injury and strategies to avoid or reduce avoidable harm.