Drug Dosing in Acute Kidney Injury

The prevalence of acute kidney injury (AKI) among hospitalized patients has increased sharply over the past 10 to 20 years. One complicating factor in this population is that many pharmacologic agents that are administered to these patients are handled, to some degree, by the kidneys. These medications may experience altered pharmacokinetic and pharmacodynamic profiles in patients with renal dysfunction, increasing the chances of drug misadventures. Historically, drug dosing in patients with AKI has been approached in the same manner as in patients with chronic renal insufficiency (CRI). The majority of dosing recommendations for AKI have been extrapolated from studies performed in patients with stable CRI. Renal drug clearance, composed of glomerular filtration, tubular secretion, and renal drug metabolism, is affected by renal dysfunction. It is clear that there is a reduction in renal clearance of drugs and toxins in both AKI and CRI. However, the type of renal dysfunction may affect other parameters of drug handling. Thus, dosing stratagems extrapolated from patients with CRI may result in subtherapeutic drug concentrations and ineffective treatment. Achieving a balance between under- and overdosing requires rigorous monitoring and individualized dosing. Key words: acute kidney injury, drug dosing, pharmacokinetics