Therapeutic change of HMG-CoA reductase inhibitors in patients with coronary artery disease.

Abstract

To evaluate short-term outcomes when atorvastatin was substituted for pravastatin or simvastatin in patients with coronary artery disease. Open-label, fixed-dosage, one-way crossover from pravastatin and simvastatin to atorvastatin. University-affiliated hospital and outpatient clinics. Eighty patients with coronary artery disease with a minimum baseline low-density lipoprotein (LDL) above 130 mg/dl: 20 were treated with pravastatin 20 mg/day, 20 with pravastatin 40 mg/day, 20 with simvastatin 20 mg/day, and 20 with simvastatin 40 mg/day for a minimum of 6 months, with a prescription refill rate of 80% or greater. Intervention. Before crossover, patients had a fasting lipid profile determined and were questioned about side effects of pravastatin and simvastatin. All patients were switched to atorvastatin 10 mg/day. After 12 weeks of atorvastatin therapy, a repeat fasting lipid profile was obtained and patients were questioned about side effects with the drug. Baseline demographic and clinical characteristics of the treatment groups were not significantly different with the exception of a lower baseline LDL in patients receiving pravastatin 20 mg/day. Baseline LDL values were as follows: pravastatin 20 mg/day, 158+/-26 mg/dl; pravastatin 40 mg/day, 176+/-22 mg/dl; simvastatin 20 mg/day, 177+/-27 mg/dl; and simvastatin 40 mg/day, 177+/-27 mg/dl. Reductions in LDL after treatment with pravastatin or simvastatin were as follows: pravastatin 20 mg/day, 22%; pravastatin 40 mg/day, 32%; simvastatin 20 mg/day, 33%; and simvastatin 40 mg/day, 38%. Patients achieving LDL goal with initial therapy were as follows: pravastatin 20 mg/day, 5%; pravastatin 40 mg/day, 5%; simvastatin 20 mg/day, 20%; and simvastatin 40 mg/day, 30%. After the switch to atorvastatin 10 mg/day, reductions in LDL were as follows: pravastatin 20 mg/day, 39% (p<0.001); pravastatin 40 mg/day, 38% (p<0.01); simvastatin 20 mg/day, 39% (p=0.04); and simvastatin 40 mg/day, 38% (p=0.83). Patients achieving LDL goals with atorvastatin 10 mg/day were as follows: pravastatin 20 mg/day, 60%; pravastatin 40 mg/day, 30%; simvastatin 20 mg/day, 25%; and simvastatin 40 mg/day, 30%. The frequency of side effects was similar for all three statins. Based on annual average wholesale price, atorvastatin 10 mg/day was more cost-effective than all pravastatin and simvastatin regimens. Therapeutic interchange from pravastatin 20 and 40 mg/day and simvastatin 20 mg/day to atorvastatin 10 mg/day was associated with both cost savings and significant reductions in LDL. The change from simvastatin 40 mg/day to atorvastatin 10 mg/day was associated with cost savings and an equivalent reduction in LDL.