A systematic review and meta-analysis on the therapeutic equivalence of statins

P>Background: Statins are the most commonly prescribed agents for hypercholesterolemia because of their efficacy and tolerability. As the number of patients in need of statin therapy continues to increase, information regarding the relative efficacy and safety of statins is required for decision-making. Objective: This study will use systematic review to compare the efficacy and safety profiles of different statins at different doses and determine the therapeutically equivalent doses of statins to achieve a specific level of low-density lipoprotein cholesterol (LDL-C) lowering effect. Methods: Publications of head-to-head randomized controlled trials (RCTs) of statins were retrieved from the Oregon state database (1966-2004), MEDLINE (2005-April of 2006), EMBASE (2005-April of 2006), and the Cochrane Controlled Trials Registry (up to the first quarter of 2006). The publications were evaluated with predetermined criteria by a reviewer before they were included in the review. The mean change in cholesterol level of each statin was calculated and weighted by number of subjects involved in each RCT. Where possible, meta-analysis was performed to generate pooled estimates of the cholesterol lowering effect of statins and the difference between statins. Results: Seventy-five studies reporting RCTs of head-to-head comparisons on statins were included. Most studies had similar baseline characteristics, except the rosuvastatin related studies. A daily dose of atorvastatin 10 mg, fluvastatin 80 mg, lovastatin 40-80 mg, and simvastatin 20 mg could decrease LDL-C by 30-40%, and fluvastatin 40 mg, lovastatin 10-20 mg, pravastatin 20-40 mg, and simvastatin 10 mg could decrease LDL-C by 20-30%. The only two statins that could reduce LDL-C more than 40% were rosuvastatin and atorvastatin at a daily dose of 20 mg or higher. Meta-analysis indicated a statistically significant but clinically minor difference (< 7%) between statins in cholesterol lowering effect. Comparisons of coronary heart disease prevention and safety could not be made because of insufficient data. Conclusions: At comparable doses, statins are therapeutically equivalent in reducing LDL-C.