Statins: Adherence and side-effects

Abstract

Many patients either do not adhere to, or fail to persist with, long-term lipid-lowering therapy. This unfavourable medication utilisation behaviour compromises potential treatment benefit. In retrospective studies, patients aged 50-65 had the highest adherence rates, while both younger and older patients had lower rates. Patients with pre-existing cardiovascular disease adhere better than those in primary prevention. Financial barriers may impair adherence. At the individual patient level, health beliefs, perceptions of own cardiovascular risk and need for medication, concerns about side-effects and inconvenience of treatment may influence adherence. In clinical trials, regular reminders to patients have been shown to improve adherence, but each patient will require an individually tailored treatment strategy. Myopathy is the most common clinically relevant adverse effect of statins. The clinical severity of statin myopathy is highly variable, ranging from mild muscle ache to rare instances of rhabdomyolysis. Risk factors for statin myopathy include age, statin dose, hypothyroidism, medications that inhibit statin metabolism, combined statin and fibrate therapy, and renal impairment. Alternative causes of myopathy should be excluded before muscular symptoms are ascribed to statins. The management of statin myopathy is guided by the severity of symptoms and the creatine kinase level. Potential management strategies include statin dechallenge and rechallenge, statin dose reduction, statin switching, non-daily dosing and use of alternative lipid-lowering agents, such as ezetimibe. Statins rarely cause severe liver disease. Mild liver enzyme elevations are seen relatively frequently in patients starting statins, but are usually not clinically important. Patients with persistently elevated liver enzymes should be investigated to determine the cause of liver disease. Patients with stable, well-compensated liver disease can be prescribed statins, provided they are closely monitored.