The safety and tolerability of rosuvastatin were assessed (as of August 2003) using data from 12,400 patients who received 5 to 40 mg of rosuvastatin in a multinational phase II/III program, which represented 12,212 patient-years of continuous exposure to rosuvastatin. An integrated database was used to examine adverse events and laboratory data. In placebo-controlled trials, adverse events, irrespective of causality assessment, occurred in 57.4% of patients who received 5 to 40 mg of rosuvastatin (n = 744) and 56.8% of patients who received placebo (n = 382). In fixed-dose trials with comparator statins, 5 to 40 mg of rosuvastatin showed an adverse event profile similar to those for 10 to 80 mg of atorvastatin, 10 to 80 mg of simvastatin, and 10 to 40 mg of pravastatin. Clinically significant elevations in alanine aminotransferase (>3 times the upper limit of normal) and creatine kinase (>10 times the upper limit of normal) were uncommon (<or=0.2%) in the groups that received rosuvastatin and comparator statins. Myopathy (creatine kinase >10 times the upper limit of normal with muscle symptoms) that was possibly related to treatment occurred in <or=0.03% of patients who took rosuvastatin at doses <or=40 mg. A positive finding of proteinuria with dipstick testing at rosuvastatin doses <or=40 mg was comparable to that seen with other statins, and the development of proteinuria was not predictive of acute or progressive renal disease. No deaths in the program were attributed to rosuvastatin, and no rhabdomyolysis occurred in patients who received 5 to 40 mg of rosuvastatin. Rosuvastatin was well tolerated by a broad range of patients who had dyslipidemia, and its safety profile was similar to those of the comparator statins investigated in this extensive clinical program.