A clinician's guide to statin drug-drug interactions

After reading the article, the practitioner will:
► Better understand the different enzyme systems involved in statin metabolism and intrapatient differences.
► Be able to predict potential drug interactions based on changes in the area under the curve for statin concentrations.
► Be able to better interpret package labeling with respect to drug-drug interactions.
► Identify common prescription and nonprescription medications that interact with statins.
► Identify special populations that may be at risk for statin drug-drug interactions.

The statins are widely used worldwide to reduce risk for cardiovascular events in both the primary and secondary prevention settings. Although generally quite safe, the statins can be associated with a variety of serious side adverse effects, including myalgia, myopathy, and changes in plasma enzymes of hepatic origin. Although rare, the most serious of these is rhabdomyolysis. Several drugs can interfere with the metabolism and disposal of the statins, thereby increasing risk for adverse events. It is important that clinicians treating patients with statins be aware of the potential for drug-drug interactions between each statin and specific other drugs and take measures to prevent them. The prediction of potential drug-drug interactions derives from basic pharmacokinetic principles. Certain drug interactions are predicted by measuring the effect of interacting drugs on blood plasma concentrations of the statin. Individual patient variations resulting in part from polymorphisms in the metabolizing enzymes confound some of these predictions. Based on these known effects, a new classification for predicting statin drug interactions is proposed. This report discusses likely prescription and nonprescription interactions as well as potential alternatives for special populations.