Changes in prescription patterns before and after reporting of the Ezetimibe and Simvastatin in Hypercholesterolemia Enhances Atherosclerosis Regression trial (ENHANCE) results and expected effects on low-density lipoprotein-cholesterol reduction

Background

Recent trends suggest a decreased use of ezetimibe/simvastatin combination and coadministered ezetimibe plus statin therapies.

Objective

This analysis evaluated changes in prescription patterns for ezetimibe/simvastatin, ezetimibe plus statins, and statin therapies and expected effects on low-density lipoprotein cholesterol (LDL-C) lowering during 2007 to 2008.

Methods

Prescription pattern changes were assessed by the use of patient-level data from the IMS Health Longitudinal Rx database during two time periods, July 14, 2007 to January 13, 2008 (n = 8,813,674) and January 14, 2008 to July 13, 2008 (n = 9,131,030), 6 months before and after reporting of the results of The Ezetimibe and Simvastatin in Hypercholesterolemia Enhances Atherosclerosis Regression trial (ENHANCE) trial on January 14, 2008. Expected LDL-C reductions were estimated using data from previous controlled clinical trials.

Results

During 6 months post-ENHANCE, greater proportions of patients were switched from ezetimibe/simvastatin and ezetimibe plus statins to other lipid-lowering therapies by health care providers than 6 months pre-ENHANCE (21.1% vs 6.0% and 46.9% vs 38.5%, differences: −15.06% [95% confidence interval −15.14%, −14.97%] and −8.43% [95% confidence interval −8.70%, −8.17%], respectively). Greater proportions of these patients switched to statin monotherapy in the later than earlier period. Prescription patterns were similar for statins during both time periods, although fewer patients switched to ezetimibe/simvastatin and ezetimibe plus statin therapies post-ENHANCE. In both time periods, greater proportions of patients on ezetimibe/simvastatin and ezetimibe plus statins switched to less-than-equivalent LDL-C lowering efficacy doses of statins than those on statin therapy. On the basis of previous clinical data for these therapies, smaller LDL-C reductions would be expected in patients who switched from ezetimibe/simvastatin and ezetimibe plus statins to statins, despite a trend toward switching to greater statin doses in the later time period.

Conclusions

More patients switched from ezetimibe/simvastatin and ezetimibe plus statin to statin monotherapy 6 months after the reporting of the ENHANCE trial, the majority of which were prescribed less potent, LDL-C–lowering therapies. On the basis of the known LDL-C lowering efficacies for these therapies, such changes would be expected to increase LDL-C levels in these patients and may reduce the proportion of patients who achieve guideline-recommended LDL-C goals.

Keywords: ENHANCE, Ezetimibe/simvastatin, LDL-C, Statin