Efficacy of atorvastatin compared with simvastatin in patients with hypercholesterolemia

Atorvastatin, a new enantiomerically pure synthetic statin, has shown a marked low-density lipoprotein (LDL) cholesterol reduction at doses ranging from 10 to 80 mg/d. This trial was designed to compare the efficacy of atorvastatin 10 mg with simvastatin 10 mg and 20 mg, the latter dose being commonly used in some countries.

A parallel group, randomized, PROBE, multicenter study was conducted to compare the efficacy of 10 mg/d atorvastatin with that of 10 mg/d simvastatin and 20 mg/d simvastatin in patients with primary hypercholesterolemia. After a 6-week diet-placebo lead-in period, 272 patients with LDL cholesterol > or = 160 mg/dL and triglycerides < or = 300 mg/dL were randomized to 6 weeks of treatment with atorvastatin 10 mg (109 patients), simvastatin 20 mg (109 patients), or simvastatin 10 mg (54 patients). In the main analysis, which tested the equivalence of atorvastatin 10 mg and simvastatin 20 mg, the mean percent change in LDL cholesterol for atorvastatin 10 mg (-37.0%) was greater than and not equivalent to simvastatin 20 mg (-33.8%). In the secondary analysis, which compared the efficacy of atorvastatin 10 mg with that of simvastatin 10 mg, the mean decrease in LDL cholesterol was significantly greater (P < .001) for atorvastatin 10 mg than for simvastatin 10 mg (-37.0% vs. -28.9%). The two drugs were well tolerated, with an incidence of clinical and biochemical side effects similar among the 3 treatment groups.

In primary hypercholesterolemia, atorvastatin 10 mg was more effective and nonequivalent to simvastatin 20 mg and significantly more effective than simvastatin 10 mg for reducing LDL cholesterol levels.