Objectives: To examine specific indications for patients receiving therapy with gemfibrozil plus simvastatin at doses of more than 10 mg daily and determine whether these patient-specific indications met Adult Treatment Panel (ATP) III criteria for combination therapy; and secondarily to identify any complications occurring between August 30, 2002, and May 1, 2003.
Design: Retrospective cohort study.
Setting: Tertiary care, university-affiliated, Southern Arizona Veterans Affairs Healthcare System from August 30, 2002, to May 1, 2003.
Patients: 80 patients with active prescriptions for gemfibrozil at any dose and simvastatin at doses of more than 10 mg daily as of August 30, 2002; and 23 patients who had been prescribed this drug at other institutions.
Intervention: Retrospective chart review.
Main outcome measures: Frequency of meeting ATP III criteria for combination therapy with gemfibrozil and simvastatin was the primary outcome measure (primary).
Results: Of the 80 patients, 45 (56%) met ATP III guidelines for combination therapy. Among the 80 patients started on these drugs at this VA facility, gemfibrozil was added to simvastatin in 61 patients, simvastatin was added to gemfibrozil in 18, and the agents were begun simultaneously for 1 patient. Common errors included combination treatment when LDL cholesterol values could not be calculated (because of serum triglycerides levels exceeding 400 mg/dL); use of gemfibrozil at triglyceride levels lower than the 500 mg/dL with attainment of non-HDL goals; and use of gemfibrozil when triglyceride levels were not measured. One death secondary to rhabdomyolysis occurred in a patient whose care did not meet ATP III guidelines.
Conclusion: Combination therapy with simvastatin and gemfibrozil often did not meet ATP III standards. A higher risk of serious adverse events results from combining these drugs, and systems to improve adherence to guidelines may improve the safety of treating dyslipidemic patients.