Comparison of low-dose simvastatin and gemfibrozil in the treatment of elevated plasma cholesterol. A multicenter study. The Simvastatin Study Group.

A 12-week, randomized, double-blind, multicenter study was undertaken to compare the efficacy, tolerability, and safety of simvastatin and gemfibrozil in 290 patients with primary hypercholesterolemia. Patients in stratum I (initial low-density lipoprotein cholesterol level less than 195 mg/dl) received simvastatin 5 to 10 mg once every afternoon; patients in stratum II (initial low-density lipoprotein cholesterol level at least 195 mg/dl) received 10 to 20 mg once every afternoon. Gemfibrozil was given in a constant dosage of 600 mg twice daily in both strata. Simvastatin reduced low-density lipoprotein cholesterol levels by 26 and 34 percent in strata I and II, respectively. The corresponding reductions brought about by gemfibrozil were 18 and 17 percent. High-density lipoprotein cholesterol was increased by 7 and 9 percent by simvastatin and by 17 and 16 percent by gemfibrozil in strata I and II, respectively. Ratios of low-density to high-density lipoprotein cholesterol were reduced by approximately 25 percent by simvastatin 5 to 10 mg once every afternoon and gemfibrozil 600 mg twice daily, but were reduced by 37 percent by simvastatin 10 to 20 mg once every afternoon. Both drugs reduced plasma triglyceride levels, but gemfibrozil was much more effective. The short-term tolerability and safety of both drugs appeared to be good during the 12-week study. The results suggest that both drugs have useful but distinctly different lipid-modifying properties.