Taking simvastatin in the morning compared with in the evening: randomised controlled trial.
Statins are widely prescribed for the primary and secondary prevention of coronary artery disease. They act by inhibiting the enzyme HMG CoA reductase, which controls synthesis of cholesterol in the liver. Most manufacturers of statins recommend that they are taken at night, on the basis of physiological studies which show that most cholesterol is synthesised when dietary intake is at its lowest. One small clinical trial found that taking smaller doses of simvastatin than are used in treatment, in the morning, was less efficient. However, a trial using atorvastatin found no significant difference in cholesterol concentrations between patients taking the statin in the morning and those taking it in the evening. Doubt has been cast on whether statins need to be taken at night, particularly as many patients also receive treatment with other cardioprotective drugs and compliance may be compromised by multiple dosing. We determined whether taking simvastatin in the morning had significantly different efficiency from taking it in the evening, by measuring cholesterol concentrations in fasting patients’ serum.