Pharmacoepidemiology Safety Study of Fibrate and Statin Concomitant Therapy

Abstract

Combinations of statins and fibrates may be increasingly prescribed to achieve lipid goals in high-risk patients and those with other cardiovascular risk factors, such as mixed dyslipidemia. The purpose of this retrospective cohort study was to compare rates of hospitalization for specific diagnoses in a cohort of new users of statins or fibrates, using claims data from a large United States health insurer. New users of statin, fibrate, or statin-fibrate therapy from 2004 to 2007 were identified; followed for hospitalization with rhabdomyolysis, renal impairment, hepatic injury, or pancreatitis; and confirmed by medical record review. Incidence rates (IRs) were compared across categories of fibrate or statin use, with adjusted IR ratios estimated using Poisson regression. A total of 584,784 patients initiated statins or fibrates. The IR of rhabdomyolysis in statins was 3.30 per 100,000 patient-years; the adjusted IR ratio for statin-fenofibrate combinations compared to statins alone was 3.75 (95% confidence interval 1.23 to 11.40). The IRs of renal impairment and pancreatitis in statins were 108.87 per 100,000 patient-years and 45.76 per 100,000 patient-years, respectively; the adjusted IR ratios for statin-fenofibrate combinations compared to statins alone were 1.47 (95% confidence interval 1.12 to 1.93) and 2.87 (95% confidence interval 2.05 to 4.02), respectively. The IR of hepatic injury with statins was 8.57 per 100,000 patient-years, with no risk difference between exposure groups. In conclusion, the risk for rhabdomyolysis was low, although higher in patients newly treated with statin-fibrate concurrent therapy than those treated with either as monotherapy. The risk for pancreatitis was higher in patients treated with fenofibrate, whether in combination with statins or alone.