Effect of Rosuvastatin on Carotid Intima-Media Thickness in Children With Heterozygous Familial Hypercholesterolemia: The CHARON Study (Hypercholesterolemia in Children and Adolescents Taking Rosuvastatin Open Label).

BACKGROUND: Heterozygous familial hypercholesterolemia (HeFH) is an autosomal dominant disorder leading to premature atherosclerosis. Children with HeFH exhibit early signs of atherosclerosis manifested by increased carotid intima-media thickness (IMT). In this study, we assessed the effect of 2-year treatment with rosuvastatin on carotid IMT in children with HeFH. METHODS: Children with HeFH (age, 6-<18 years) and low-density lipoprotein cholesterol >4.9 mmol/L or >4.1 mmol/L in combination with other risk factors received rosuvastatin for 2 years, starting at 5 mg once daily, with uptitration to 10 mg (age, 6-<10 years) or 20 mg (age, 10-<18 years). Carotid IMT was assessed by ultrasonography at baseline and 12 and 24 months in all patients and in age-matched unaffected siblings. Carotid IMT was measured at 3 locations (common carotid artery, carotid bulb, internal carotid artery) in both the left and right carotid arteries. A linear mixed-effects model was used to evaluate differences in carotid IMT between children with HeFH and the unaffected siblings. P values were adjusted for age, sex, carotid artery site, and family relations. RESULTS: At baseline, mean±SD carotid IMT was significantly greater for the 197 children with HeFH compared with the 65 unaffected siblings (0.397±0.049 and 0.377±0.045 mm, respectively; P=0.001). During 2 years of follow-up, the change in carotid IMT was 0.0054 mm/y (95% confidence interval, 0.0030-0.0082) in children with HeFH and 0.0143 mm/y (95% confidence interval, 0.0095-0.0192) in unaffected siblings (P=0.002). The end-of-study difference in mean carotid IMT between children with HeFH and unaffected siblings after 2 years was no longer significant (0.408±0.043 and 0.402±0.042 mm, respectively; P=0.2). CONCLUSIONS: In children with HeFH who were ≥6 years of age, carotid IMT was significantly greater at baseline compared with unaffected siblings. Rosuvastatin treatment for 2 years resulted in significantly less progression of increased carotid IMT in children with HeFH than untreated unaffected siblings. As a result, no difference in carotid IMT could be detected between the 2 groups after 2 years of rosuvastatin. These findings support the value of early initiation of statin treatment for low-density lipoprotein cholesterol reduction in children with HeFH. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01078675.

Population pharmacokinetics of rosuvastatin in pediatric patients with heterozygous familial hypercholesterolemia.

PURPOSE: Data from two clinical studies (hyperCholesterolaemia in cHildren and Adolescents taking Rosuvastatin OpeN label [CHARON; NCT01078675] and Study 4522IL/0086) were used to describe rosuvastatin pharmacokinetics in patients with heterozygous familial hypercholesterolemia aged ≥6 to <18 years. METHODS: Rosuvastatin concentration-time data were analyzed via non-linear mixed-effects modeling (NONMEM), with clearance (CL/F) as the pre-defined key pharmacokinetic parameter of interest. In addition, descriptive comparisons between pediatric patients and adults (healthy and dyslipidemic) were performed. The dataset included 214 pediatric patients, with 2,029 rosuvastatin concentrations. RESULTS: A linear two-compartment model with first-order absorption and elimination processes adequately described the combined dataset. Weight and gender were significant covariates for CL/F, with moderate between-patient variability remaining (coefficient of variation (CV) 40 %): CL/F in female children was approximately 30 % lower than in male children, and there was a twofold mean difference in CL/F across the observed weight range. Age was not a significant covariate after accounting for weight and gender differences. However, weight and gender only reduced between-patient variability from 45 (without covariates) to 40 % and are considered unlikely to be clinically relevant. CONCLUSIONS: Rosuvastatin pharmacokinetics appeared generally predictable with respect to dose, and time (study duration) and the exposure (dose-normalized area under the plasma concentration-time curve at steady state (AUCss)) in children and adolescents appeared to be similar or lower than adult patients with dyslipidemia.

Estimating the variability in fraction absorbed as a paradigm for informing formulation development in early clinical drug development.

PURPOSE: Inter-subject variability in oral drug absorption is usually reported using bioavailability, which has the components: fraction absorbed (fa), fraction passing the gut wall (fg) and fraction escaping hepatic metabolism (fh). In this study, we sought to separate the absorption (fa∗fg) and elimination (fh) components of bioavailability to study variability of absorption and to investigate the effect of formulations, gastric pH and food on absorption variability. METHODS: Four compounds from the AstraZeneca database with a range of reported bioavailabilities (high, intermediate 1&2 and low) were selected. First, a disposition model using intravenous data was developed; Second, intrinsic clearance and hence hepatic extraction ratio was estimated based on the "well stirred" model; lastly, the oral data were included to enable estimation of fa∗fg as a separate component to hepatic extraction. Population pharmacokinetic model fitting was undertaken with NONMEM v.7.2. RESULTS: The limiting step in absorption for intermediate 1 was dissolution rate and fa∗fg variability increased under elevated gastric pH (15% vs. 38%, respectively). Absorption of solution formulation intermediate 2 increased by 17% in the presence of food but the prolonged release formulation's absorption didn't differ under fasted or fed state. Variability wasn't affected by food for both formulations (~30%). For the low bioavailable compound, variability decreased when formulated as a prolonged-release formulation (39% vs. 15%). CONCLUSIONS: The method described here enables an exploration of drug absorption inter-subject variability using population pharmacokinetics. Implementation of such an approach may aid the formulation design process through a better understanding of the factors affecting oral drug absorption variability.

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.

Inter-subject variability in intestinal drug solubility.

Variability in oral drug absorption is a well-known phenomenon, but it is often overlooked for its potential effects in oral drug delivery. Understanding the mechanisms behind absorption variability is crucial to understanding and predicting drug pharmacokinetics. In this study, the solubility of furosemide and dipyridamole - drugs known to have highly variable oral bioavailabilities - was investigated in individual ileostomy fluids from 10 subjects with ulcerative colitis. For comparison, drug solubility was also determined in pooled upper gastrointestinal fluids from healthy human subjects and simulated intestinal fluids. Ileostomy fluid characterization revealed high variability in buffer capacity and to a lesser degree for pH. Drug solubility in ileostomy fluids showed high variability. Correlation analysis revealed that dipyridamole solubility in these fluids is pH-dependent, whereas furosemide solubility was highly correlated to buffer capacity and pH. The implications of these results might partly explain the high variability in bioavailability in vivo, assuming that most of the observed variability is due to the absorption, and not the elimination, process.

Efficacy and safety of rosuvastatin therapy in children and adolescents with familial hypercholesterolemia: Results from the CHARON study.

OBJECTIVE: Heterozygous familial hypercholesterolemia (HeFH) is an autosomal dominant disorder leading to premature atherosclerosis. Guidelines recommend initiating statins early to reduce low-density lipoprotein cholesterol (LDL-C). Studies have evaluated rosuvastatin in children aged ≥10 years, but its efficacy and safety in younger children is unknown. METHODS: Children with HeFH and fasting LDL-C >4.92 mmol/L (190 mg/dL) or >4.10 mmol/L (>158 mg/dL) with other cardiovascular risk factors received rosuvastatin 5 mg daily. Based on LDL-C targets (<2.85 mmol/L [<110 mg/dL]), rosuvastatin could be uptitrated to 10 mg (aged 6-9 years) or 20 mg (aged 10-17 years). Treatment lasted 2 years. Changes in lipid values, growth, sexual maturation, and adverse events (AEs) were assessed. RESULTS: The intention-to-treat analysis included 197 patients. At 24 months, LDL-C was reduced by 43, 45, and 35% vs baseline in patients aged 6-9, 10-13, and 14-17 years, respectively (P < .001 for all groups). Most AEs were mild. Intermittent myalgia was reported in 11 (6%) patients and did not lead to discontinuation of rosuvastatin treatment. Serious AEs were reported by 9 (5%) patients, all considered unrelated to treatment by the investigators. No clinically important changes in hepatic biochemistry were reported. Rosuvastatin treatment did not appear to adversely affect height, weight, or sexual maturation. CONCLUSIONS: In HeFH patients aged 6-17 years, rosuvastatin 5-20 mg over 2 years significantly reduced LDL-C compared with baseline. Treatment was well tolerated, with no adverse effects on growth or sexual maturation.

Effect of itraconazole on the pharmacokinetics of rosuvastatin.

BACKGROUND: Rosuvastatin is a new 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. Itraconazole, an inhibitor of cytochrome P450 (CYP) 3A4 and the transport protein P-glycoprotein, is known to interact with other HMG-CoA reductase inhibitors. The current trials aimed to examine in vivo the effect of itraconazole on the pharmacokinetics of rosuvastatin. METHODS: Two randomized, double-blind, placebo-controlled, 2-way crossover trials were performed. Healthy male volunteers (trial A, n = 12; trial B, n = 14) received itraconazole, 200 mg, or placebo once daily for 5 days; on day 4, 10 mg (trial A) or 80 mg (trial B) of rosuvastatin was coadministered. Plasma concentrations of rosuvastatin, rosuvastatin-lactone (trial A only), and active and total HMG-CoA reductase inhibitors were measured up to 96 hours after dosing. RESULTS: After coadministration with itraconazole, the rosuvastatin geometric least-square mean for the treatment ratio was increased by 39% for AUC(0-ct) (area under the rosuvastatin plasma concentration-time curve from time 0 to the last common time at which quantifiable concentrations were obtained for both treatments within a volunteer in trial A) and by 28% for AUC(0-t) (area under the rosuvastatin plasma concentration-time curve from time 0 to the time of the last quantifiable concentration in trial B), with the treatment ratio for maximum observed plasma drug concentration increased by 36% in trial A and 15% in trial B compared with placebo. For trial A (but not for trial B), the upper boundary of the 90% confidence interval for the treatment ratios fell outside the preset limits (0.7-1.43). The 95% confidence intervals for all treatment ratios (except maximum observed plasma drug concentration in trial B) did not include 1. These results indicate that itraconazole produces a modest increase in plasma concentrations of rosuvastatin. Rosuvastatin accounted for the majority of the circulating active HMG-CoA reductase inhibitors (> or =87%) and most of the total inhibitors (> or =75%). CONCLUSIONS: Itraconazole produced modest increases in rosuvastatin plasma concentrations, which are unlikely to be of clinical relevance. The results support previous in vitro metabolism findings that CYP3A4 plays a minor role in the limited metabolism of rosuvastatin.

Rosuvastatin pharmacokinetics in heart transplant recipients administered an antirejection regimen including cyclosporine.

BACKGROUND: Cyclosporine (INN, ciclosporin) increases the systemic exposure of all statins. Therefore rosuvastatin pharmacokinetic parameters were assessed in an open-label trial involving stable heart transplant recipients (> or =6 months after transplant) on an antirejection regimen including cyclosporine. Rosuvastatin has been shown to be a substrate for the human liver transporter organic anion transporting polypeptide C (OATP-C). Inhibition of this transporter could increase plasma concentrations of rosuvastatin. Therefore the effect of cyclosporine on rosuvastatin uptake by cells expressing OATP-C was also examined. METHODS: Ten subjects were assessed while taking 10 mg rosuvastatin for 10 days; 5 of these were then assessed while taking 20 mg rosuvastatin for 10 days. Rosuvastatin steady-state area under the plasma concentration-time curve from time 0 to 24 hours [AUC(0-24)] and maximum observed plasma concentration (Cmax) were compared with values in controls (historical data from 21 healthy volunteers taking 10 mg rosuvastatin). Rosuvastatin uptake by OATP-C-transfected Xenopus oocytes was also studied by use of radiolabeled rosuvastatin with and without cyclosporine. RESULTS: In transplant recipients taking 10 mg rosuvastatin, geometric mean values and percent coefficient of variation for steady-state AUC(0-24) and Cmax were 284 ng. h/mL (31.3%) and 48.7 ng/mL (47.2%), respectively. In controls, these values were 40.1 ng. h/mL (39.4%) and 4.58 ng/mL (46.9%), respectively. Compared with control values, AUC(0-24) and Cmax were increased 7.1-fold and 10.6-fold, respectively, in transplant recipients. In transplant recipients taking 20 mg rosuvastatin, these parameters increased less than dose-proportionally. Rosuvastatin had no effect on cyclosporine blood concentrations. The in vitro results demonstrate that rosuvastatin is a good substrate for OATP-C-mediated hepatic uptake (association constant, 8.5 +/- 1.1 micromol/L) and that cyclosporine is an effective inhibitor of this process (50% inhibition constant, 2.2 +/- 0.4 micromol/L when the rosuvastatin concentration was 5 micromol/L). CONCLUSIONS: Rosuvastatin exposure was significantly increased in transplant recipients on an antirejection regimen including cyclosporine. Cyclosporine inhibition of OATP-C-mediated rosuvastatin hepatic uptake may be the mechanism of the drug-drug interaction. Coadministration of rosuvastatin with cyclosporine needs to be undertaken with caution.

The effect of gemfibrozil on the pharmacokinetics of rosuvastatin.

BACKGROUND: Coadministration of statins and gemfibrozil is associated with an increased risk for myopathy, which may be due in part to a pharmacokinetic interaction. Therefore the effect of gemfibrozil on rosuvastatin pharmacokinetics was assessed in healthy volunteers. Rosuvastatin has been shown to be a substrate for the human hepatic uptake transporter organic anion transporter 2 (OATP2). Inhibition of this transporter could increase plasma concentrations of rosuvastatin. The effect of gemfibrozil on rosuvastatin uptake by cells expressing OATP2 was also examined. METHODS: In a randomized, double-blind, 2-period crossover trial, 20 healthy volunteers were given oral doses of gemfibrozil, 600 mg, or placebo twice daily for 7 days. On the fourth morning of each dosing period, a single oral dose of rosuvastatin, 80 mg, was coadministered. Plasma concentrations of rosuvastatin, N-desmethyl rosuvastatin, and rosuvastatin-lactone were measured. In addition, the effect of gemfibrozil on the uptake of radiolabeled rosuvastatin by OATP2-transfected Xenopus oocytes was studied. RESULTS: Gemfibrozil increased the rosuvastatin area under the plasma concentration-time curve from time 0 to the time of the last quantifiable concentration [AUC(0-t)] 1.88-fold (90% confidence interval, 1.60-2.21) and the maximum observed rosuvastatin plasma concentration (C(max)) 2.21-fold (90% confidence interval, 1.81-2.69) compared with placebo. N-desmethyl rosuvastatin AUC(0-t) and C(max) decreased by 48% and 39%, respectively. Pharmacokinetics of rosuvastatin-lactone was unchanged. The in vitro results indicate that the maximum gemfibrozil inhibition of rosuvastatin OATP2-mediated uptake was 50%; the inhibition constant for the inhibitory process was 4.0 +/- 1.3 micromol/L. CONCLUSIONS: Gemfibrozil increased rosuvastatin plasma concentrations approximately 2-fold, which is similar to the effect of gemfibrozil on pravastatin, simvastatin acid, and lovastatin acid plasma concentrations and substantially less than the effect observed for cerivastatin. Gemfibrozil inhibition of OATP2-mediated rosuvastatin hepatic uptake may contribute to the mechanism of the drug-drug interaction. Care is warranted when gemfibrozil is coadministered with rosuvastatin and other statins.

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.

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 AUC(0-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 (AUC(0-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.

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.

A double-blind, randomized, incomplete crossover trial to assess the dose proportionality of rosuvastatin in healthy volunteers.

BACKGROUND: Rosuvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has been developed for the treatment of patients with dyslipidemia. OBJECTIVE: This study assessed the dose proportionality and pharmacokinetics of single oral doses of rosuvastatin in healthy volunteers. METHODS: This was a double-blind, randomized, incomplete crossover trial consisting of 3 trial days separated by >/=7-day washout periods. Healthy men were allocated to 1 of 2 treatment regimens: rosuvastatin 10, 20, and 80 mg, or rosuvastatin 10, 40, and 80 mg, administered as single doses on separate trial days in random order. Pharmacokinetic and tolerability assessments were made up to 96 hours after administration. Dose proportionality was tested using the power-law approach. RESULTS: Eighteen healthy white men participated in the trial (mean age, 41.2 years; mean height, 178.4 cm; mean body weight, 81.6 kg). Geometric mean rosuvastatin maximum plasma concentration (C(max)) values of 3.75, 6.79, 10.3, and 30.1 ng/mL were achieved at a median time to C(max) of 5.0 hours after doses of 10, 20, 40, and 80 mg, respectively. The corresponding geometric mean values for rosuvastatin area under the plasma concentration-time curve from time 0 to time of the last measurable concentration (AUC(0-t)) were 31.6, 56.8, 98.2, and 268 ng.h/mL. C(max) and AUC(0-t) were both linearly related to dose. The estimates of the proportionality coefficient (90% CI) for CmaX and AUC(o-t) were 0.999 (0.898-1.099) and 1.024 (0.941-1.107), respectively; all values fell within the prespecified range of 0.847 to 1.153. Rosuvastatin was well tolerated in this group of healthy men when administered orally at doses of 10 to 80 mg. CONCLUSION: Rosuvastatin systemic exposure was dose proportional over the dose range of 10 to 80 mg.

Absolute oral bioavailability of rosuvastatin in healthy white adult male volunteers.

BACKGROUND: Rosuvastatin is a 3-hydroxy-3-methylglutaryl coenzyme A-reductase inhibitor developed for the treatment of dyslipidemia. The results of clinical trials suggest that it is effective and well tolerated. OBJECTIVES: The goals of this study were to determine the absolute bioavailability of an oral dose of rosuvastatin and to describe the intravenous pharmacokinetics of rosuvastatin in healthy volunteers. METHODS: This was a randomized, open-label, 2-way crossover study consisting of 2 trial days separated by a > or =7-day washout period. Healthy male adult volunteers were given a single oral dose of rosuvastatin 40 mg on one trial day and an intravenous infusion of rosuvastatin 8 mg over 4 hours on the other. Pharmacokinetic and tolerability assessments were conducted up to 96 hours after dosing. A 3-compartment pharmacokinetic model was fitted to the plasma concentration-time profiles obtained for each volunteer after intravenous dosing. RESULTS: Ten white male volunteers entered and completed the trial. Their mean age was 35.7 years (range, 21-51 years), their mean height was 177 cm (range, 169-182 cm), and their mean body weight was 77.6 kg (range, 68-85 kg). The absolute oral bioavailability of rosuvastatin was estimated to be 20.1%,and the hepatic extraction ratio was estimated to be 0.63. The mean volume of distribution at steady state was 134 L. Renal clearance accounted for approximately 28% of total plasma clearance (48.9 L/h). Single oral and intravenous doses of rosuvastatin were well tolerated in this small number of healthy male volunteers. CONCLUSIONS: The absolute oral bioavailability of rosuvastatin in these 10 healthy volunteers was approximately 20%, and absorption was estimated to be 50%. The volume of distribution at steady state was consistent with extensive distribution of rosuvastatin to the tissues. The modest absolute oral bioavailability and high hepatic extraction of rosuvastatin are consistent with first-pass uptake into the liver after oral dosing. Rosuvastatin was cleared by both renal and nonrenal routes; tubular secretion was the predominant renal process.

Metabolism, excretion, and pharmacokinetics of rosuvastatin in healthy adult male volunteers.

BACKGROUND: Rosuvastatin is a 3-hydroxy-3-methylglutaryl coenzyme A-reductase inhibitor, or statin, that has been developed for the treatment of dyslipidemia. OBJECTIVE: This study assessed the metabolism, excretion, and pharmacokinetics of a single oral dose of radiolabeled rosuvastatin ([14C]-rosuvastatin) in healthy volunteers. METHODS: This was a nonrandomized, open-label, single-day trial. Healthy adult male volunteers were given a single oral dose of [14C]-rosuvastatin 20 mg (20 mL [14C]-rosuvastatin solution, nominally containing 50 microCi radioactivity). Blood, urine, and fecal samples were collected up to 10 days after dosing. Tolerability assessments were made up to 10 days after dosing (trial completion) and at a follow-up visit within 14 days of trial completion. RESULTS: Six white male volunteers aged 36 to 52 years (mean, 43.7 years) participated in the trial. The geometric mean peak plasma concentration (C(max)) of rosuvastatin was 6.06 ng/mL and was reached at a median of 5 hours after dosing. At C(max), rosuvastatin accounted for approximately 50% of the circulating radioactive material. Approximately 90% of the rosuvastatin dose was recovered in feces, with the remainder recovered in urine. The majority of the dose (approximately 70%) was recovered within 72 hours after dosing; excretion was complete by 10 days after dosing. Metabolite profiles in feces indicated that rosuvastatin was excreted largely unchanged (76.8% of the dose). Two metabolites-rosuvastatin-5S-lactone and N-desmethyl rosuvastatin-were present in excreta. [14C]-rosuvastatin was well tolerated; 2 volunteers reported 4 mild adverse events that resolved without treatment. CONCLUSIONS: The majority of the rosuvastatin dose was excreted unchanged. Given the absolute bioavailability (20%) and estimated absorption (approximately 50%) of rosuvastatin, this finding suggests that metabolism is a minor route of clearance for this agent.

Validation and application of an assay for the determination of mevalonic acid in human plasma by liquid chromatography tandem mass spectrometry.

The validation of a method for the determination of mevalonic acid (MVA; after conversion to the lactone, MVAL) in human plasma, using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS-MS), is reported. MVAL and deuterated internal standard were extracted from human plasma samples using automated solid-phase extraction. Analysis was conducted by column-switching, reversed-phase LC-MS-MS, using two hyper-cross-linked styrene-divinylbenzene copolymer sorbent reversed-phase columns. An assay range of 0.2-35 ng/ml and a lower limit of quantitation (LLOQ) of 0.2 ng/ml were achieved with acceptable accuracy and precision. MVA was stable in plasma under a variety of storage conditions.

Quantification of the N-desmethyl metabolite of rosuvastatin in human plasma by automated SPE followed by HPLC with tandem MS detection.

A selective, accurate and precise assay was developed for the quantification in human plasma of the N-desmethyl metabolite of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor rosuvastatin. The assay-employing automated SPE followed by HPLC with positive ion electrospray tandem MS (HPLC-MS/MS)-was validated. The standard curve range for N-desmethyl rosuvastatin in human plasma was 0.5-30 ng/ml with 0.5 ng/ml being the limit of quantification. Plasma samples were mixed 1:1 with sodium acetate buffer (pH 4.0; 0.1M) soon after separation from red blood cells. N-Desmethyl rosuvastatin was stable in plasma:buffer at room temperature for 24h and at -70 degrees C for 12 months. The assay was applied successfully to the quantification of N-desmethyl rosuvastatin in human plasma following administration of rosuvastatin.

Pharmacokinetics and tolerability of vandetanib in Chinese patients with solid, malignant tumors: an open-label, phase I, rising multiple-dose study.

BACKGROUND: Vandetanib (ZD6474) is an orally available inhibitor of 3 signaling pathways important in tumor progression: vascular endothelial growth factor receptor, epidermal growth factor receptor, and rearranged during transfection tyrosine kinase activity. Current development of vandetanib is focused on the treatment of non-small-cell lung cancer and other tumor types, including thyroid cancer. This study was conducted as a requirement for regulatory submission for vandetanib in China. OBJECTIVE: To determine the pharmacokinetics of vandetanib in Chinese patients with advanced, solid, malignant tumors and to compare these with data obtained in Japanese and Western populations. METHODS: Phase I consisted of a nonrandomized, open-label, single-center study conducted in Guangzhou, China. Adult patients (12 per treatment) who had tumors refractory to standard treatments or for whom no appropriate therapies existed received oral vandetanib (100 mg every other day, 100 mg once daily, or 300 mg once daily) until disease progression or discontinuation in the study. The initial cohort was dosed at 100 mg every other day. Once at least 3 patients had received this dose of vandetanib for 28 days without experiencing dose-limiting toxicity, a second cohort at 100 mg once daily was started. Following the same criteria, the third cohort received 300 mg once daily. Pharmacokinetics, tolerability, and tumor response were assessed. The pharmacokinetics of vandetanib in Chinese, Western, and Japanese patients were compared through a combined population pharmacokinetic model. Tolerability was assessed by recording adverse events and monitoring physical examination, body weight, performance status, vital signs, urinalysis, biochemistry, hematology, and 12-lead electrocardiogram. RESULTS: Thirty-six patients were enrolled (age range 21-82 years, 56% male, body mass index range 17.6-33.0 kg/m(2)). Thirty-three of 36 patients (92%) were World Health Organization performance status 0-1. Vandetanib pharmacokinetics were linear over the dose range studied with AUC(ss) for the 300 mg once daily group (38611 ng/h/mL) being 3.6-fold higher than that for the 100 mg once daily group (10826 ng/h/mL). Absorption was relatively slow following a single 100- or 300-mg dose, with T(max) ranging from 2 to 10 hours. Interpatient variability in C(max SS) and AUC(SS) was relatively high, with the coefficient of variation ranging from 29.1% to 40.6%. Vandetanib plasma clearance was slow (7.8-9.2 L/h) and was independent of dose. The most common drug-related adverse events were rash (42%) and diarrhea (39%). No QT(C) prolongation was observed. Hypertension was reported as an adverse event in 3 patients. There were no clinically relevant changes in hematology, urinalysis, or World Health Organization performance status. Elevation of alanine aminotransferase was reported as an adverse event in 1 patient. One patient with medullary thyroid cancer showed a partial tumor response. Population pharmacokinetic analysis suggests that vandetanib pharmacokinetics appear to be comparable in Chinese, Western, and Japanese patients. CONCLUSIONS: The pharmacokinetic properties of vandetanib in these Chinese patients were characterized by low plasma clearance of approximately 8 L/h, a long half-life of approximately 8 to 10 days, and an accumulation of approximately 8-fold to 15-fold on multiple dosing. In these Chinese patients, the pharmacokinetic profile of vandetanib appeared to be comparable with that observed in Japanese and Western populations. Oral doses up to 300 mg once daily appeared to be well tolerated.

The effect of a combination antacid preparation containing aluminium hydroxide and magnesium hydroxide on rosuvastatin pharmacokinetics.

OBJECTIVE: Rosuvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor used for the treatment of dyslipidaemia, may be co-administered with antacids in clinical practice. This trial assessed the effect of simultaneous and separated administration of an antacid preparation containing aluminium hydroxide 220 mg/5 mL and magnesium hydroxide 195 mg/5 mL (co-magaldrox 195/220) on the pharmacokinetics of rosuvastatin. RESEARCH DESIGN AND METHODS: A randomised, open-label, three-way crossover trial was performed. Healthy male volunteers (n = 14) received a single dose of rosuvastatin 40 mg alone, rosuvastatin 40 mg plus 20 mL antacid suspension taken simultaneously, and rosuvastatin 40 mg plus 20 mL antacid suspension taken 2 h after rosuvastatin on three separate occasions with a washout of > or = 7 days between each. MAIN OUTCOME MEASURES: The primary parameters were area under the rosuvastatin plasma concentration-time curve from time zero to the last quantifiable concentration (AUC(0-t)) and maximum observed rosuvastatin plasma concentration (C(max)) in the absence and presence of antacid. RESULTS: When rosuvastatin and antacid were given simultaneously, the antacid reduced the rosuvastatin AUC(0-t) by 54% (90% confidence interval [CI] for the treatment 0.40-0.53) and C(max) by 50% (90% CI 0.41-0.60). When the antacid was given 2 h after rosuvastatin, the antacid reduced the rosuvastatin AUC(0-t) by 22% (90% CI 0.68-0.90) and the C(max) by 16% (90% CI 0.70-1.01). The effect of repeated antacid administration was not studied and it cannot be discounted that this may have resulted in a stronger interaction than that observed here. CONCLUSIONS: Simultaneous dosing with rosuvastatin and antacid resulted in a decrease in rosuvastatin systemic exposure of approximately 50%. This effect was mitigated when antacid was administered 2 h after rosuvastatin.