Pharmacodynamic effects and pharmacokinetics of a new HMG-CoA reductase inhibitor,rosuvastatin, after morning or evening administration in healthy volunteers

AIMS: To compare the lipid-regulating effects and steady-state pharmacokinetics of rosuvastatin, a new synthetic hydroxy methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, following repeated morning and evening administration in volunteers with fasting serum low-density lipoprotein cholesterol (LDL-C) concentrations < 4.14 mmol l-1. METHODS: In this open-label two-way crossover trial 24 healthy adult volunteers were randomized to receive rosuvastatin 10 mg orally each morning (07.00 h) or evening (18.00 h) for 14 days. After a 4 week washout period, volunteers received the alternative regimen for 14 days. Rosuvastatin was administered in the absence of food. RESULTS: Reductions from baseline in serum concentrations of LDL-C (-41.3%[morning]vs-44.2%[evening]), total cholesterol (-30.9%vs-31.8%), triglycerides (-17.1%vs-22.7%), and apolipoprotein B (-32.4%vs-35.3%) were similar following morning and evening administration. AUC(0,24 h) for plasma mevalonic acid (MVA), an in vivo marker of HMG-CoA reductase activity, decreased by -29.9% (morning) vs-32.6% (evening). Urinary excretion of MVA declined by -33.6% (morning) vs-29.2% (evening). The steady-state pharmacokinetics of rosuvastatin were very similar following the morning and evening dosing regimens. The Cmax values were 4.58 vs 4.54 ng ml-1, and AUC(0,24 h) values were 40.1 vs 42.7 ng ml-1 h, following morning and evening administration, respectively. There were no serious adverse events during the trial, and rosuvastatin was well tolerated after morning and evening administration. CONCLUSIONS: The pharmacodynamic effects and pharmacokinetics of rosuvastatin are not dependent on time of dosing. Morning or evening administration is equally effective in lowering LDL-C.