Impact of therapeutic interchange from pravastatin to lovastatin in a veterans affairs medical center

Objective: To evaluate the impact of a therapeutic interchange from pravastatin to lovastatin on treatment outcomes, quality of life, patient satisfaction, and costs. Study Design: A prospective cohort study of 170 patients switched from pravastatin to lovastatin from September 1997 through November 1997. Patients and Methods: The therapeutic interchange program promoting lovastatin as the preferred agent went into effect June 2, 1997 after Merck & Co. was awarded the Veterans Health Administration national contract for 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Patients were switched to lovastatin by either their primary care physician during routine clinic visits or the pharmacist by mail. The following outcomes were measured before and after conversion to lovastatin: lipid values, liver function tests, National Cholesterol Education Program (NCEP) low-density cholesterol (LDL-C) goals achieved, quality of life (QOL) (measured by the Medical Outcomes Study 36-item short-form health survey [SF-36]), medication tolerance (measured with a global symptom survey), patient satisfaction, and cost-minimization analysis. Results: Lipid values and liver function test results were similar for pravastatin and lovastatin treatment. Forty percent of patients achieved NCEP LDL-C goals before and after formulary conversion. There were no significant differences between pravastatin and lovastatin in QOL, medication tolerance, and patient satisfaction. The projected cost savings from this therapeutic interchange? was approximately $211,000 annually. Conclusion: Therapeutic interchange from pravastatin to lovastatin resulted in substantial cost savings. QOL, patient satisfaction, and achievement of NCEP LDL-C goals were maintained.