Abstract
OBJECTIVE: To describe safety and efficacy laboratory monitoring of statin therapy at the University of Colorado Hospital Outpatient Clinics over a period of 3 years prior to the revised United States Food and Drug Administration statin labeling. METHODS: This retrospective, observational study evaluated serum laboratory monitoring for safety and efficacy of statin therapy between July 2008 and June 2011. Adult patients prescribed chronic statin therapy were included. The primary objective of this study was to describe the frequency of outpatient liver function tests, lipid panels, and creatine kinase for patients on chronic statin therapy. RESULTS: A total of 143 patients met study criteria. Over a 3-year period, the mean maximum frequency of measurements per patient of serum hepatic transaminases, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was higher than lipid panel measurements (5.2 ± 4.4 and 4.2 ± 2.0 respectively, p = 0.021). Only 22 of 143 patients (15.4%) had an elevation in ALT or AST. All elevations were less than three times the upper limit of normal and statin therapy was continued without changes in response to these elevations. Creatine kinase, though not a routine monitoring test, was infrequently measured (mean maximum frequency of measurements per patient 0.3 ± 0.8). CONCLUSION: Serum hepatic transaminases were routinely monitored in patients treated with chronic statin therapy. Given the absence of significant serum hepatic transaminase elevations, and clinician response to minor elevations, our data indicate that routine serum laboratory evaluations for statin toxicity are excessive.