Dennis W. Schneck

Preclinical and clinical pharmacology of Rosuvastatin, a new 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor.

Rosuvastatin (formerly ZD4522) is a new 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) with distinct pharmacologic properties. Compared with most other statins, it is relatively hydrophilic, similar in this respect to pravastatin. Rosuvastatin has been shown to be a comparatively potent inhibitor of HMG-CoA reductase activity in a purified preparation of the catalytic domain of the human enzyme, as well as in rat and human hepatic microsomes. In rat hepatocytes, rosuvastatin was found to have significantly higher potency as an inhibitor of cholesterol synthesis than 5 other statins. Rosuvastatin was approximately 1,000-fold more potent in rat hepatocytes than in rat fibroblasts. Further studies in rat hepatocytes demonstrated that rosuvastatin is taken up into these cells by a high-affinity active uptake process. Rosuvastatin was also taken up selectively into the liver after intravenous administration in rats. Potent and prolonged HMG-CoA reductase inhibitory activity has been demonstrated after oral administration to rats and dogs. Pharmacokinetic studies in humans using oral doses of 5 to 80 mg showed that maximum plasma concentrations and areas under the concentration-time curve are approximately linear with dose. The terminal half-life is approximately 20 hours. Studies with human hepatic microsomes and human hepatocytes have suggested little or no metabolism via the cytochrome P-450 3A4 isoenzyme. On the basis of these observations, it is suggested that rosuvastatin has the potential to exert a profound effect on atherogenic lipoproteins.

Rosuvastatin pharmacokinetics and pharmacogenetics in white and Asian subjects residing in the same environment

Systemic exposure to rosuvastatin had been observed to be approximately 2‐fold higher in Japanese subjects living in Japan compared with white subjects in Western Europe or the United States. The organic anion transporting polypeptide 1B1 contributes to the hepatic uptake of rosuvastatin. Polymorphisms in the SLCO1B1 gene can lead to reduced transport function in vitro (T521>C). This study was conducted to determine whether the pharmacokinetic differences between Japanese and white subjects extended to other Asian ethnic groups and to determine whether polymorphisms in the SLCO1B1 gene contribute to any pharmacokinetic differences observed.

Comparative effects of rosuvastatin and atorvastatin across their dose ranges in patients with hypercholesterolemia and without active arterial disease.

The lipid-lowering effects of rosuvastatin and atorvastatin were determined across their dose ranges in a 6-week, randomized, double-blind trial. Three hundred seventy-four hypercholesterolemic patients with fasting low-density lipoprotein (LDL) cholesterol > or =160 but <250 mg/dl (> or =4.14 but <6.47 mmol/L) and fasting triglycerides <400 mg/dl (<4.52 mmol/L) and without active arterial disease within 3 months of entry received once-daily rosuvastatin (5, 10, 20, 40, or 80 mg [n = 209]) or atorvastatin (10, 20, 40, or 80 mg [n = 165]). The percentage decrease in plasma LDL cholesterol versus dose was log-linear for each drug, ranging from -46.6% to -61.9% for rosuvastatin 10 and 80 mg, compared with -38.2% to -53.5% for atorvastatin 10 and 80 mg. The dose curve for rosuvastatin yielded an 8.4% greater decrease in LDL cholesterol compared with atorvastatin at any given dose (p <0.001). Similarly greater decreases were observed for rosuvastatin across the dose range in total cholesterol (-4.9%), non-high-density lipoprotein (non-HDL) cholesterol (-7.0%), apolipoprotein B (-6.3%), and related ratios versus atorvastatin (all p <0.001). Because dose responses for HDL cholesterol, triglycerides, and apolipoprotein A-I were non-log-linear and nonparallel between the 2 drugs, percentage changes from baseline were compared at each dose. Significantly greater increases for rosuvastatin compared with atorvastatin were observed for HDL cholesterol at 40 and 80 mg, and for apolipoprotein A-I at 80 mg. Significantly greater triglyceride decreases were seen at 80 mg with atorvastatin over rosuvastatin. Both rosuvastatin and atorvastatin were well tolerated over 6 weeks.

A Review and Assessment of Potential Sources of Ethnic Differences in Drug Responsiveness

The International Conference on Harmonization (ICH) E5 guidelines were developed to provide a general framework for evaluating the potential impact of ethnic factors on the acceptability of foreign clinical data, with the underlying objective to facilitate global drug development and registration. It is well recognized that all drugs exhibit significant intersubject variability in pharmacokinetics and pharmacologic response and that such differences vary considerably among individual drugs and depend on a variety of factors. One such potential factor involves ethnicity. The objective of the present work was to perform an extensive review of the world literature on ethnic differences in drug disposition and responsiveness to determine their general significance in relation to drug development and registration. A few examples of suspected ethnic differences in pharmacokinetics or pharmacodynamics were identified. The available literature, however, was found to be heterologous, including a variety of study designs and research methodologies, and most of the publications were on drugs that were approved a long time ago.

An open-label, randomized, three-way crossover trial of the effects of coadministration of rosuvastatin and fenofibrate on the pharmacokinetic properties of rosuvastatin and fenofibric acid in healthy male volunteers

BACKGROUND Rosuvastatin and fenofibrate are lipid-regulating agents with different modes of action. Patients with dyslipidemia who have not achieved treatment targets with monotherapy may benefit from the combination of these agents. OBJECTIVE The effect of coadministration of rosuvastatin and fenofibrate on the steady-state pharmacokinetics of rosuvastatin and fenofibric acid (the active metabolite of fenofibrate) was assessed in healthy volunteers. METHODS This was an open-label, randomized, 3-way crossover trial consisting of three 7-day treatment periods. Healthy male volunteers received one of the following treatment regimens in each period: rosuvastatin 10 mg orally once daily; fenofibrate 67 mg orally TID; and rosuvastatin + fenofibrate dosed as above. The steady-state pharmacokinetics of rosuvastatin and fenofibric acid, both as substrate and as interacting drug, were investigated on day 7 of dosing. Treatment effects were assessed by construction of 90% CIs around the ratios of the geometric least-square means for rosuvastatin + fenofibrate/rosuvastatin and rosuvastatin + fenofibrate/fenofibrate for the area under the plasma concentration-time curve (AUC) and maximum plasma concentration (derived from analysis of variance of log-transformed parameters). RESULTS Fourteen healthy male volunteers participated in the study. When rosuvastatin was coadministered with fenofibrate, there were minor increases in the AUC from 0 to 24 hours and maximum concentration (Cmax) of rosuvastatin: the respective geometric least-square means increased by 7% (90% CI, 1.00-1.15) and 21% (90% CI, 1.14-1.28). The pharmacokinetic parameters of fenofibric acid were similar when fenofibrate was dosed alone and with rosuvastatin: the geometric least-square means for fenofibric acid AUC from 0 to 8 hours and Cmax decreased by 4% (90% CI, 0.90-1.02) and 9% (90% CI, 0.84-1.00), respectively. The treatments were well tolerated alone and in combination. CONCLUSION Coadministration of rosuvastatin and fenofibrate produced minimal changes in rosuvastatin and fenofibric acid exposure.

No effect of age or gender on the pharmacokinetics of rosuvastatin: a new HMG-CoA reductase inhibitor.

The effects of age and gender on the pharmacokinetics of rosuvastatin (Crestor™) were assessed in healthy young (18–35 years) and elderly (< 65 years) males and females in this open, nonrandomized, noncontrolled, parallel‐group trial. Sixteen males and 16 females (8 young and elderly volunteers per gender group) were enrolled. Mean (range) ages were 24 (18–33) and 68 (65–73) years for young and elderly volunteers, respectively. Volunteers were given a single oral 40 mg dose of rosuvastatin. Blood samples for measurement of rosuvastatin plasma concentration were collected up to 96 hours following dosing. Age and gender effects were assessed by constructing 90% confidence intervals (CIs) around the ratios of young/elderly and male/female geometric least square means (glsmeans) for AUC(0‐t) and Cmax (derived from ANOVA of log‐transformed parameters). Small differences in rosuvastatin pharmacokinetics were noted between age and gender groups. Glsmean AUC(0‐t) was 6% higher (90% CI = 0.86‐1.30) and glsmean Cmax 12% higher (90% CI= 0.83‐1.51) in the young compared with the elderly group. Glsmean AUC(0‐t) was 9% lower (90% CI= 0.74‐1.12) and glsmean Cmax 18% lower (90% CI = 0.61‐1.11) in the male compared with the female group. These small differences are not considered clinically relevant, and dose adjustments based on age or gender are not anticipated. Rosuvastatin was well tolerated in all volunteers.

Rosuvastatin improves the atherogenic and atheroprotective lipid profiles in patients with hypertriglyceridemia.

BackgroundWe examined the effects of rosuvastatin treatment on triglyceride levels and lipid measures in a parallel-group multicenter trial (4522IL/0035) in patients with hypertriglyceridemia (Fredrickson Type IIb or IV). MethodsAfter a 6-week dietary lead-in period while on a National Cholesterol Education Program step I diet, 156 patients with fasting triglyceride levels ≥300 and <800 mg/dl were randomized to 6 weeks of double-blinded treatment: once-daily rosuvastatin of 5, 10, 20, 40 or 80 mg or placebo. The primary end point was mean percentage change from baseline in total serum triglyceride levels at week 6 as determined by analysis of variance. ResultsRosuvastatin at all doses produced significant mean reductions in triglycerides compared with placebo (–18 to –40 compared with +2.9%, P ≤ 0.001); median reductions in triglycerides with rosuvastatin at 5–80 mg ranged from –21 to –46%. All doses of rosuvastatin significantly reduced levels of atherogenic lipoprotein and apolipoproteins over placebo, including low-density lipoprotein cholesterol, total cholesterol, non-high-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, apolipoprotein B and apolipoprotein C-III. Statistically significant increases in high-density lipoprotein cholesterol were observed with rosuvastatin doses >5 mg. The occurrence of adverse events was generally low and not dose related, although some adverse events occurred more frequently in the rosuvastatin 80 mg group. ConclusionsRosuvastatin reduced triglyceride levels and improved the overall atherogenic and atheroprotective lipid profiles in hypertriglyceridemic patients.

No Effect of Rosuvastatin on the Pharmacokinetics of Digoxin in Healthy Volunteers

The effect of rosuvastatin on the pharmacokinetics of digoxin was assessed in 18 healthy male volunteers in this double‐blind, randomized, two‐way crossover trial. Volunteers were dosed with rosuvastatin (40 mg once daily) or placebo to steady state before being given a single dose of digoxin 0.5 mg. Blood and urine samples for the measurement of serum and urine digoxin concentrations were collected up to 96 hours following dosing. The effect of rosuvastatin was assessed by constructing 90% confidence intervals (CIs) around the treatment ratios (rosuvastatin + digoxin/placebo + digoxin) for digoxin exposure. The geometric least square mean AUC0‐t and Cmax of digoxin were only 4% higher when the drug was coadministered with rosuvastatin compared to placebo. The 90% CIs for both treatment ratios (AUC0‐t = 0.88‐1.24; Cmax = 0.89‐1.22) fell within the prespecified margin of 0.74 to 1.35; therefore, no significant pharmacokinetic interaction occurred between rosuvastatin and digoxin. The geometric mean amount of digoxin excreted into the urine and its renal clearance were similar with rosuvastatin and placebo. These results demonstrate that rosuvastatin has no effect on the pharmacokinetics of digoxin. Coadministration of rosuvastatin and digoxin was well tolerated.

Effect of Rosuvastatin on Warfarin Pharmacodynamics and Pharmacokinetics

The effect of rosuvastatin on warfarin pharmacodynamics and pharmacokinetics was assessed in 2 trials. In trial A (a randomized, double‐blind, 2‐period crossover study), 18 healthy volunteers were given rosuvastatin 40 mg or placebo on demand (o.d.) for 10 days with 1 dose of warfarin 25 mg on day 7. In trial B (an open‐label, 2‐period study), 7 patients receiving warfarin therapy with stable international normalized ratio values between 2 and 3 were coadministered rosuvastatin 10 mg o.d. for up to 14 days, which increased to rosuvastatin 80 mg if the international normalized ratio values were <3 at the end of this period. The results indicated that rosuvastatin can enhance the anticoagulant effect of warfarin. The mechanism of this drug‐drug interaction is unknown. Rosuvastatin had no effect on the total plasma concentrations of the warfarin enantiomers, but the free plasma fractions of the enantiomers were not measured. Appropriate monitoring of the international normalized ratio is indicated when this drug combination is coadministered.

Population pharmacokinetics of rosuvastatin: implications of renal impairment, race, and dyslipidaemia.

ABSTRACT Objectives: To build the structural model of pharmacokinetics for rosuvastatin and evaluate the impact of demographic characteristics including renal function on its pharmacokinetic parameters. Methods: A population pharmacokinetic analysis of rosuvastatin in healthy volunteers, subjects with dyslipidaemia, and renal failure patients was performed using non-linear mixed-effects modelling and a two-compartment pharmacokinetic model with simultaneous first- and zero-order absorption. Demographic covariates, dyslipidaemic state and renal function were evaluated for their impact on pharmacokinetic parameters by step-wise additions or deletions using the likelihood ratio test. Results: Typical pharmacokinetic parameters were estimated for a healthy white male subject. For example, apparent oral clearance (CL/F ) was estimated to be 257 L/h. Age, smoking status, weight, body surface area, and lean body mass had no significant effect on rosuvastatin pharmacokinetics. The model predicted that CL/F for subjects with creatinine clearance (CLCR ) of 30 mL/min (moderate renal impairment) and of 50 mL/min (mild renal impairment) was 17% and 9.7% lower, respectively, relative to subjects with CLCR of 94 mL/min, the data set median value. CL/F was reduced by 71.1% and 43.7% in subjects with dyslipidaemia and in Asian subjects, respectively. Conclusions: Reduction of CL/F of rosuvastatin is not considered clinically significant for patients with mild-to-moderate renal impairment. Rosuvastatin CL/F was reduced in subjects with dyslipidaemia, but it is important to realise that the safety/efficacy profile of rosuvastatin has been well established in this population. However, the potential for increased exposure in Asian subjects should be considered when initiating rosuvastatin treatment or increasing dose in this population.