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

Simulating Healthy Participant Pharmacokinetics for Renal and Hepatic Impairment Studies: Retrospective Assessment of the Approach

The recruitment of a parallel, healthy participants (HPs) arm in renal and hepatic impairment (RI and HI) studies is a common strategy to assess differences in pharmacokinetics. Limitations in this approach include the underpowered estimate of exposure differences and the use of the drug in a population for which there is no benefit. Recently, a method was published by Purohit et. al. (2023) that leveraged prior population pharmacokinetic (PopPK) modeling-based simulation to infer the distribution of exposure ratios between the RI/HI arms and HPs. The approach was successful, but it was a single example with a robust model having several iterations of development and fitting to extensive HP data. To test in more studies and models at different stages of development, our catalogue of RI/HI studies was searched, and those with suitable properties and from programs with available models were analyzed with the simulation approach. There were 9 studies included in the analysis. Most studies were associated with models that would have been available at the time (ATT) of the study, and all had a current, final model. For 3 studies, the HP PK was not predicted well by the ATT (2) or final (1) models. In comparison to conventional analysis of variance (ANOVA), the simulation approach provided similar point estimates and confidence intervals of exposure ratios. This PopPK based approach can be considered as a method of choice in situations where the simulation of HP data would not be an extrapolation, and when no other complicating factors are present.

A Bioequivalence Study of Ezetimibe/Rosuvastatin Fixed Dose Combination (10 mg/10 mg) Versus the Individual Formulations Taken Concomitantly

INTRODUCTION

This study evaluated the bioequivalence of ezetimibe/rosuvastatin fixed dose combination compared to the concomitant administration of individual formulations (ezetimibe and rosuvastatin) in Chinese healthy subjects under fasting conditions.

METHODS

This was a phase I, randomized, open-label, two-treatment, two-period, two-sequence, crossover study conducted in healthy Chinese participants under fasting conditions. Cmax, AUC0-t, and AUC0-∞ from test and individual reference formulations were evaluated to assess bioequivalence. The safety assessments included adverse events (AEs)/treatment-emergent adverse events (TEAEs), potential clinically significant abnormalities (PCSAs) in vital signs, 12-lead electrocardiogram (12-ECG), and clinical laboratory parameters.

RESULTS

Of the 68 subjects enrolled, 67 were treated. Systemic exposure to rosuvastatin based on Cmax, AUC0-t, and AUC0-∞ was similar in both treatments, with respective arithmetic values 12.4 ng/ml, 117 ng·h/mL, and 120 ng·h/mL for test formulation and 12.7 ng/ml, 120 ng·h/mL, and 123 ng·h/mL for reference formulations. Similarly, systemic exposure to unconjugated ezetimibe was 4.14 ng/ml, 89.7 ng·h/mL, and 102 ng·h/mL for the test formulation and 3.80 ng/ml, 89.7 ng·h/mL, and 102 ng·h/mL for reference formulations. Systemic exposure to total ezetimibe was 70.5 ng/ml, 664 ng·h/mL, and 718 ng·h/mL for test formulation and 60.2 ng/ml, 648 ng·h/mL, and 702 ng·h/mL for reference formulations. The point estimates for rosuvastatin unconjugated ezetimibe and total ezetimibe were in the acceptable range of 0.80-1.25. No deaths or serious adverse events were reported.

CONCLUSIONS

Fixed dose combination of ezetimibe/rosuvastatin (10 mg/10 mg) achieved bioequivalence with reference to commercial tablets.

TRIAL REGISTRATION NUMBER

CTR20202108.

Ethnicity based differences in statin use and hypercholesterolemia control among patients with premature coronary artery disease-results of I-PAD study

Background

Statins use is the most important treatment for high LDL cholesterol in patients with premature coronary artery disease (CAD). Previous reports have shown racial and gender differences in statin use in the general population, but this wasn't studied in premature CAD based on different ethnicities.

Methods and results

Our study includes 1917 men and women with confirmed diagnosis of premature CAD. Logistic regression model was used to evaluate the high LDL cholesterol control in the groups and the OR with 95% confidence interval (CI) was reported as the effect size. After adjustment for confounders, the odds of controlling LDL in women taking Lovastatin, Rosuvastatin, and Simvastatin were 0.27 (0.03, 0.45) lower in comparison with men. Also, in participant who took 3 types of statins, the odds of controlling LDL were significantly different between Lor and Arab compared with Fars ethnicity. After adjustment to all confounders (full model), the odds of controlling LDL were lower for Gilak in Lovastatin, Rosuvastatin, and Simvastatin by 0.64 (0.47, 0.75); 0.61 (0.43, 0.73); 0.63 (0.46, 0.74) respectively and higher for Arab in Lovastatin, Rosuvastatin, and Simvastatin by 4.63 (18.28, 0.73); 4.67 (17.47, 0.74); 4.55 (17.03, 0.71) respectively compared to Fars.

Conclusions

Major differences in different gender and ethnicities may have had led to disparities in statin use and LDL control. Awareness of the statins impact on high LDL cholesterol based on different ethnicities can help health decision-makers to close the observed gaps in statin use and control LDL to prevent CAD problems.

The frequency of rs2231142 in ABCG2 among Asian subgroups: implications for personalized rosuvastatin dosing

Statins are widely used medications for the primary and secondary prevention of cardiovascular diseases. Statin-induced musculoskeletal symptoms are the primary adverse drug events contributing to poor adherence to lipid-lowering therapy. Rosuvastatin is characterized by interindividual differences in systemic exposure among different patient population subgroups. The missense variant Q141K within ABCG2, highly prevalent in some Asian subgroups, results in decreased transporter efflux function and increased exposure to rosuvastatin. We aim to highlight the implications of ABCG2 genotype in prescribing rosuvastatin and the ramifications of interpopulation differences in Q141K frequencies in the starting dose of rosuvastatin in major Asian subgroups, using the most recent genetic-based guidelines. The high frequency of Q141K in Filipinos could warrant a lower starting rosuvastatin dose versus non-Filipinos. The Q141K genotype frequencies in Asian subgroups suggest significant interpopulation differences, reinforcing the need to move beyond race-based to genotype-based rosuvastatin dosing.

Functional in vitro characterization of SLCO1B1 variants and simulation of the clinical pharmacokinetic impact of impaired OATP1B1 function

Organic Anion Transporting Polypeptide 1B1 is important to the hepatic elimination and distribution of many drugs. If OATP1B1 function is decreased, it can increase plasma exposure of e.g. several statins leading to increased risk of muscle toxicity. First, we examined the impact of three naturally occurring rare variants and the frequent SLCO1B1 c.388A>G variant on in vitro transport activity with cellular uptake assay using two substrates: 2', 7'-dichlorofluorescein (DCF) and rosuvastatin. Secondly, LC-MS/MS based quantitative targeted absolute proteomics measured the OATP1B1 protein abundance in crude membrane fractions of HEK293 cells over-expressing these SNVs. Additionally, we simulated the effect of impaired OATP1B1 function on rosuvastatin pharmacokinetics to estimate the need for genotype-guided dosing. R57Q impaired DCF and rosuvastatin transport significantly yet did not change protein expression considerably, while N130D and N151S did not alter activity but increased protein expression. R253Q did not change protein expression but reduced DCF uptake and increased rosuvastatin K_m. Based on pharmacokinetics simulations, doses of 30 mg (with 50% OATP1B1 function) and 20 mg (with 0% OATP1B1 function) result in plasma exposure similar to 40 mg dose (with 100% OATP1B1 function). Therefore dose reductions might be considered to avoid increased plasma exposure caused by function-impairing OATP1B1 genetic variants, such as R57Q.

Inter-ethnic differences in pharmacokinetics-is there more that unites than divides?

Inter-ethnic variability in pharmacokinetics (PK) has been attributed to several factors ranging from genetic to environmental. It is not clear how current teaching in higher education (HE) reflects what published literature suggests on this subject. This study aims to gain insights into current knowledge about inter-ethnic differences in PK based on reports from published literature and current teaching practices in HE. A systematic literature search was conducted on PubMed and Scopus to identify suitable literature to be reviewed. Insights into inter-ethnic differences in PK teaching among educators in HE and industry were determined using a questionnaire. Thirty-one percent of the studies reviewed reported inter-ethnic differences in PK, of these, 37% of authors suggested genetic polymorphism as possible explanation for the inter-ethnic differences observed. Other factors authors proposed included diet and weight differences between ethnicities. Most respondents (80%) who taught inter-ethnic difference in PK attributed inter-ethnic differences to genetic polymorphism. While genetic polymorphism is one source of variability in PK, the teaching of genetic polymorphism is better associated with interindividual variabilities rather than inter-ethnic differences in PK as there are no genes with PK implications specific to any one ethnic group. Nongenetic factors such as diet, weight, and environmental factors, should be highlighted as potential sources of interindividual variation in the PK of drugs.

Physiologically Based Pharmacokinetic Modeling of Rosuvastatin to Predict Transporter-Mediated Drug-Drug Interactions

Purpose

To build a physiologically based pharmacokinetic (PBPK) model of the clinical OATP1B1/OATP1B3/BCRP victim drug rosuvastatin for the investigation and prediction of its transporter-mediated drug-drug interactions (DDIs).

Methods

The Rosuvastatin model was developed using the open-source PBPK software PK-Sim®, following a middle-out approach. 42 clinical studies (dosing range 0.002–80.0 mg), providing rosuvastatin plasma, urine and feces data, positron emission tomography (PET) measurements of tissue concentrations and 7 different rosuvastatin DDI studies with rifampicin, gemfibrozil and probenecid as the perpetrator drugs, were included to build and qualify the model.

Results

The carefully developed and thoroughly evaluated model adequately describes the analyzed clinical data, including blood, liver, feces and urine measurements. The processes implemented to describe the rosuvastatin pharmacokinetics and DDIs are active uptake by OATP2B1, OATP1B1/OATP1B3 and OAT3, active efflux by BCRP and Pgp, metabolism by CYP2C9 and passive glomerular filtration. The available clinical rifampicin, gemfibrozil and probenecid DDI studies were modeled using in vitro inhibition constants without adjustments. The good prediction of DDIs was demonstrated by simulated rosuvastatin plasma profiles, DDI AUC_last ratios (AUC_last during DDI/AUC_last without co-administration) and DDI C_max ratios (C_max during DDI/C_max without co-administration), with all simulated DDI ratios within 1.6-fold of the observed values.

Conclusions

A whole-body PBPK model of rosuvastatin was built and qualified for the prediction of rosuvastatin pharmacokinetics and transporter-mediated DDIs. The model is freely available in the Open Systems Pharmacology model repository, to support future investigations of rosuvastatin pharmacokinetics, rosuvastatin therapy and DDI studies during model-informed drug discovery and development (MID3).

Supplementary Information

The online version contains supplementary material available at 10.1007/s11095-021-03109-6.

Personalized medicine in lipid-modifying therapy

The choice of lipid-modifying treatment is largely based on the absolute level of cardiovascular risk and baseline lipid profile. Statins are the first-line treatment for most patients requiring reduction of low-density-lipoprotein cholesterol (LDL-C) and ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitors can be added to reach LDL-C targets. Statins have some adverse effects that are somewhat predictable based on phenotypic and genetic factors. Fibrates or omega-3 fatty acids can be added if triglyceride levels remain elevated. The RNA-targeted therapeutics in development offer the possibility of selective liver targeting for specific lipoproteins such as lipoprotein(a) and long-term reduction of LDL-C with infrequent administration of a small-interfering RNA may help to overcome the problem of adherence to therapy.

Pharmacokinetic/Pharmacodynamic Modelling to Describe the Cholesterol Lowering Effect of Rosuvastatin in People Living with HIV

BACKGROUND

Rosuvastatin is a lipid-lowering agent widely prescribed in people living with HIV, which is actively transported into the liver, making it a potential victim of drug-drug interactions with antiretroviral agents.

OBJECTIVES

The aims of this study were to characterise the pharmacokinetic profile of rosuvastatin and to describe the relationship between rosuvastatin concentrations and non-high-density lipoprotein (HDL)-cholesterol levels in people living with HIV.

METHODS

A population pharmacokinetic model (NONMEM) was developed to quantify the influence of demographics, clinical characteristics and comedications on rosuvastatin pharmacokinetics. This model was combined with an indirect effect model to describe non-HDL-cholesterol measurements.

RESULTS

A two-compartment model with sequential zero- and first-order absorption best fitted the 154 rosuvastatin concentrations provided by 65 people living with HIV. None of the tested covariates significantly influenced rosuvastatin pharmacokinetics. A total of 403 non-HDL cholesterol values were available for pharmacokinetic-pharmacodynamic modelling. Baseline non-HDL cholesterol decreased by 14% and increased by 12% with etravirine and antiretroviral drugs with a known impact on the lipid profile (i.e. protease inhibitors, efavirenz, cobicistat), respectively. The baseline value was surprisingly 43% lower in people living with HIV aged 80 years compared with those aged 40 years. Simulations based on the covariate-free model predicted that, under standard rosuvastatin dosages of 5 mg and 20 mg once daily, 31% and 64% of people living with HIV would achieve non-HDL-cholesterol targets, respectively.

CONCLUSIONS

The high between-subject variability that characterises both rosuvastatin pharmacokinetic and pharmacodynamic profiles remained unexplained after the inclusion of usual covariates. Considering its limited potential for drug-drug interactions with antiretroviral agents and its potent lipid-lowering effect, rosuvastatin prescription appears safe and effective in people living with HIV with hypercholesterolaemia.

CLINICAL TRIAL REGISTRATION NO

NCT03515772.

Prior statin therapy and 30-day mortality in South Korean patients with acute respiratory distress syndrome

BACKGROUND

The effect of prior statin therapy on mortality in patients with acute respiratory distress syndrome (ARDS) remains controversial. This study aimed to investigate whether prior statin therapy was associated with lower 30-day mortality compared to non-statin use.

METHODS

This population-based cohort study used nationwide data procured from the National Health Insurance service in South Korea, and included all the adult patients admitted to a hospital for ARDS treatment between January 1, 2013 and December 31, 2017.

RESULTS

In total, 14,600 patients with ARDS were included: 4,319 were statin users and 10,281 were non-statin users. After propensity score matching, 6,046 patients with ARDS (3,023 patients in each group) were included in the analysis. The 30-day mortality of statin users was 44.4% (1,331 of 3,023), while that of non-statin users was 45.2% (1,331 of 3,023). On Cox regression analysis in the propensity score matched cohort, 30-day mortality was not significantly associated with statin use compared to non-statin use (hazard ratio: 0.95, 95% confidence interval: 0.88 to 1.02; P = .165). On Kaplan-Meier estimation, the median survival time in statin users was 45 days (95% CI: 39 to 50), while that in non-statin users was 42 days (95% CI: 37 to 47) after propensity score matching, and there was no statistical difference with the log-rank test (P = .215).

CONCLUSION

This population-based cohort study in South Korea showed that prior statin therapy was not significantly associated with 30-day mortality in patients with ARDS. Our findings should be confirmed in future prospective studies.

Pharmacokinetics of Rosuvastatin: A Systematic Review of Randomised Controlled Trials in Healthy Adults

BACKGROUND

Rosuvastatin is a lipid-lowering drug that works by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme responsible for producing cholesterol in humans. The pharmacokinetic data of rosuvastatin are considerably variable across studies.

OBJECTIVE

To review the pharmacokinetics of rosuvastatin from randomised controlled trials (RCTs) in healthy adults.

METHODS

A review of the pharmacokinetics of rosuvastatin was performed using systematic search strategies. The Sheiner method was used to summarise the pharmacokinetics of the drug.

RESULTS

Randomised controlled studies (n = 70) involving healthy subjects (n = 2355) that examined the pharmacokinetics of rosuvastatin following single and multiple doses were included in the review. Rosuvastatin is given once daily in the dose range of 5-80 mg, with 40 mg being the maximum approved daily dose. Rosuvastatin achieves maximum plasma concentration at a median of 5 h (range: 0.5-6 h) under fasting conditions following single and multiple doses. Following single doses, rosuvastatin has a mean absolute oral availability of 20%, an overall mean total clearance of 28.3 L/h and an average terminal elimination half-life of approximately 20 h. The overall mean total clearance of the drug in Caucasian subjects was 1.7-fold higher than that in healthy Chinese subjects. The systemic exposure of rosuvastatin is characterised by a large coefficient of variation (48%.) There is a small accumulation with repeated dosing. The interaction of rosuvastatin with darunavir/ritonavir was considered statistically and clinically relevant. Interactions of rosuvastatin single doses with erythromycin, fluconazole, itraconazole and antacid were statistically significant.

DISCUSSION AND CONCLUSIONS

There is considerable variation in the pharmacokinetics of rosuvastatin between races. The clinical relevance of the statistically significant drug interactions is yet to be investigated following repeated co-administration for at least 15 days, consistent with a half-life of low-density lipoprotein of 3 days.

A Microdose Cocktail to Evaluate Drug Interactions in Patients with Renal Impairment

Renal impairment (RI) is known to influence the pharmacokinetics of nonrenally eliminated drugs, although the mechanism and clinical impact is poorly understood. We assessed the impact of RI and single dose oral rifampin (RIF) on the pharmacokinetics of CYP3A, OATP1B, P-gp, and BCRP substrates using a microdose cocktail and OATP1B endogenous biomarkers. RI alone had no impact on midazolam (MDZ), maximum plasma concentration (C_max ), and area under the curve (AUC), but a progressive increase in AUC with RI severity for dabigatran (DABI), and up to ~2-fold higher AUC for pitavastatin (PTV), rosuvastatin (RSV), and atorvastatin (ATV) for all degrees of RI was observed. RIF did not impact MDZ, had a progressively smaller DABI drug-drug interaction (DDI) with increasing RI severity, a similar 3.1-fold to 4.4-fold increase in PTV and RSV AUC in healthy volunteers and patients with RI, and a diminishing DDI with RI severity from 6.1-fold to 4.7-fold for ATV. Endogenous biomarkers of OATP1B (bilirubin, coproporphyrin I/III, and sulfated bile salts) were generally not impacted by RI, and RIF effects on these biomarkers in RI were comparable or larger than those in healthy volunteers. The lack of a trend with RI severity of PTV and several OATP1B biomarkers, suggests that mechanisms beyond RI directly impacting OATP1B activity could also be considered. The DABI, RSV, and ATV data suggest an impact of RI on intestinal P-gp, and potentially BCRP activity. Therefore, DDI data from healthy volunteers may represent a worst-case scenario for clinically derisking P-gp and BCRP substrates in the setting of RI.

Medication burden and inappropriate prescription risk among elderly with advanced chronic kidney disease

BACKGROUND

Elderly patients with chronic kidney disease (CKD) frequently present comorbidities that put them at risk of polypharmacy and medication-related problems. This study aims to describe the overall medication profile of patients aged ≥75 years with advanced CKD from a multicenter French study and specifically the renally (RIMs) and potentially inappropriate-for-the-elderly medications (PIMs) that they take.

METHODS

This is a cross-sectional analysis of medication profiles of individuals aged ≥75 years with eGFR < 20 ml/min/1.73 m2 followed by a nephrologist, who collected their active prescriptions at the study inclusion visit. Medication profiles were first analyzed according to route of administration, therapeutic classification. Second, patients were classified according to their risk of potential medication-related problems, based on whether the prescription was a RIM or a PIM. RIMs and PIMs have been defined according to renal appropriateness guidelines and to Beer's criteria in the elderly. RIMs were subclassified by 4 types of category: (a) contraindication; (b) dose modification is recommended based on creatinine clearance (CrCl); (c) dose modification based on CrCl is not recommended but a maximum daily dose is mentioned, (d) no specific recommendations based on CrCl: "use with caution", "avoid in severe impairment", "careful monitoring of dose is required" "reduce the dose".

RESULTS

We collected 5196 individual medication prescriptions for 556 patients, for a median of 9 daily medications [7-11]. Antihypertensive agents, antithrombotics, and antianemics were the classes most frequently prescribed. Moreover, 77.0% of patients had at least 1 medication classified as a RIM. They accounted 31.3% of the drugs prescribed and 9.25% was contraindicated drugs. At least 1 PIM was taken by 57.6 and 45.5% of patients had at least one medication classified as RIM and PIM. The prescriptions most frequently requiring reassessment due to potential adverse effects were for proton pump inhibitors and allopurinol. The PIMs for which deprescription is especially important in this population are rilmenidine, long-term benzodiazepines, and anticholinergic drugs such as hydroxyzine.

CONCLUSION

We showed potential drug-related problems in elderly patients with advanced CKD. Healthcare providers must reassess each medication prescribed for this population, particularly the specific medications identified here.

TRIAL REGISTRATION

NCT02910908.

Preadmission Statin Use and 90-day Mortality in the Critically Ill

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

This study aimed to examine the association between preadmission statin use and 90-day mortality in critically ill patients and to investigate whether this association differed according to statin type and dose. We hypothesized that preadmission statin use was associated with lower 90-day mortality.

Methods

This retrospective cohort study analyzed the medical records of all adult patients admitted to the intensive care unit in a single tertiary academic hospital between January 2012 and December 2017. Data including preadmission statin use, statin subtype, and daily dosage were collected, and the associations between these variables and 90-day mortality after intensive care unit admission were examined. The primary endpoint was 90-day mortality.

Results

A total of 24,928 patients (7,396 statin users and 17,532 non–statin users) were included. After propensity score matching, 5,354 statin users and 7,758 non–statin users were finally included. The 90-day mortality rate was significantly higher in non–statin users (918 of 7,758; 11.8%) than in statin users (455 of 5,354; 8.5%; P &lt; 0.001). In Cox regression analysis, the 90-day mortality rate was lower among statin users than among non–statin users (hazard ratio: 0.70, 95% CI: 0.63 to 0.79; P &lt; 0.001). Rosuvastatin use was associated with 42% lower 90-day mortality (hazard ratio: 0.58, 95% CI: 0.47 to 0.72; P &lt; 0.001). There were no specific significant differences in the association between daily statin dose and 90-day mortality. In competing risk analysis, the risk of noncardiovascular 90-day mortality in statin users was 32% lower than that in non–statin users (hazard ratio: 0.68, 95% CI: 0.60 to 0.78; P &lt; 0.001). Meanwhile, cardiovascular 90-day mortality was not significantly associated with statin use.

Conclusions

Preadmission statin use was associated with a lower 90-day mortality. This association was more evident in the rosuvastatin group and with noncardiovascular 90-day mortality; no differences were seen according to daily dosage intensity.

Population-scale genomics-Enabling precision public health

The current excitement for affordable genomics technologies and national precision medicine initiatives marks a turning point in worldwide healthcare practices. The last decade of global population sequencing efforts has defined the enormous extent of genetic variation in the human population resulting in insights into differential disease burden and response to therapy within and between populations. Population-scale pharmacogenomics helps to provide insights into the choice of optimal therapies and an opportunity to estimate, predict and minimize adverse events. Such an approach can potentially empower countries to formulate national selection and dosing policies for therapeutic agents thereby promoting public health with precision. We review the breadth and depth of worldwide population-scale sequencing efforts and its implications for the implementation of clinical pharmacogenetics toward making precision medicine a reality.

Nonadherence to statins: individualized intervention strategies outside the pill box

Poor adherence to statin therapy is linked to significantly increased risk of cardiovascular events and death. Unfortunately, adherence to statins is far from optimal. This is an alarming concern for patients prescribed potentially life-saving cholesterol-lowering medication, especially for those at high risk of cardiovascular events. Research on statin adherence has only recently garnered broader attention; hence, major reasons unique to adherence to statin therapy need to be identified as well as suggestions for countermeasures. An integrated approach to minimizing barriers and enhancing facilitation at the levels of the patient, provider, and health system can help address adherence issues. Health care professionals including physicians, pharmacists, and nurses have an obligation to improve patient adherence, as routine care. In order to achieve sustained results, a multifaceted approach is indispensable.

Gaining Mechanistic Insight Into Coproporphyrin I as Endogenous Biomarker for OATP1B-Mediated Drug-Drug Interactions Using Population Pharmacokinetic Modeling and Simulation

This study evaluated coproporphyrin I (CPI) as a selective endogenous biomarker of OATP1B‐mediated drug–drug interactions (DDIs) relative to clinical probe rosuvastatin using nonlinear mixed‐effect modeling. Plasma and urine CPI data in the presence/absence of rifampicin were modeled to describe CPI synthesis, elimination clearances, and obtain rifampicin in vivo OATP Ki. The biomarker showed stable interoccasion baseline concentrations and low interindividual variability (<25%) in subjects with wildtype SLCO1B1. Biliary excretion was the dominant CPI elimination route (maximal >85%). Estimated rifampicin in vivo unbound OATP Ki (0.13 μM) using CPI data was 2‐fold lower relative to rosuvastatin. Model‐based simulations and power calculations confirmed sensitivity of CPI to identify moderate and weak OATP1B inhibitors in an adequately powered clinical study. Current analysis provides the most detailed evaluation of CPI as an endogenous OATP1B biomarker to support optimal DDI study design; further pharmacogenomic and DDI data with a panel of inhibitors are required.

Interindividual and interethnic variability in drug disposition: polymorphisms in organic anion transporting polypeptide 1B1 (OATP1B1; SLCO1B1)

OATP1B1 (SLCO1B1) is predominantly expressed at the basolateral membrane of hepatocytes and is critically important for the hepatic uptake and clearance of numerous drug substrates and endogenous compounds. In general, the organic anion transporting polypeptides (OATP; SLCO) represent a superfamily of uptake transporters that mediate the sodium-independent transport of a diverse range of amphipathic organic compounds including bile salts, steroid conjugates, thyroid hormones, anionic peptides, numerous drugs and other xenobiotic substances. OATP1B1 is highly polymorphic and a number of relevant and ethnically dependent polymorphisms have been identified and functionally characterized. In particular, the SLCO1B1 521T>C and 388A>G polymorphisms are commonly occurring variants in ethnically diverse populations and numerous in vitro and clinical studies have evaluated the consequences of these variants to interindividual differences in drug disposition and response. OATP1B1 is particularly important for the disposition of HMG-CoA reductase inhibitors, or statins, as it is known to efficiently transport most statins to their site of action within hepatocytes. Many studies have focused on the consequences of OATP1B1 variants to statin disposition in vitro and in vivo and would suggest that genetic variability in SLCO1B1 has important implications for statin pharmacokinetics, risk for statin-induced myopathy, and modulation of statin treatment response. This review describes what is currently known regarding SLCO1B1 genotype, OATP1B1 protein expression and interindividual and interethnic consequences to drug disposition, with particular focus on statin pharmacokinetics and implications for drug response and toxicity.

Racial Differences in the Cholesterol-Lowering Effect of Statin

Statin treatment to reduce low-density lipoprotein cholesterol (LDL-C) is associated with the prevention of cardiovascular events in Western patients. Similar results have been reported in studies conducted in Japan. However, the dose of statins and the degree of LDL-C reduction achieved with statins are different between Asian and Western patients. In addition, there are limited data regarding racial differences in response to statins. In this review, racial differences between Asians and Westerners in response to statins are described.

The Promises of Quantitative Proteomics in Precision Medicine

Precision medicine approach has a potential to ensure optimum efficacy and safety of drugs at individual patient level. Physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) models could play a significant role in precision medicine by predicting interindividual variability in drug disposition and response. In order to develop robust PBPK/PD models, it is imperative that the critical physiological parameters affecting drug disposition and response and their variability are precisely characterized. Currently used PBPK/PD modeling software, for example, Simcyp and Gastroplus, encompass information such as organ volumes, blood flows to organs, body fat composition, glomerular filtration rate, etc. However, the information on the interindividual variability of the majority of the proteins associated with PK and PD, for example, drug metabolizing enzymes, transporters, and receptors, are not fully incorporated into these PBPK modeling platforms. Such information is significant because the population factors such as age, genotype, disease, and gender can affect abundance or activity of these proteins. To fill this critical knowledge gap, mass spectrometry-based quantitative proteomics has emerged as an important technique to characterize interindividual variability in the protein abundance of drug metabolizing enzymes, transporters, and receptors. Integration of these quantitative proteomics data into in silico PBPK/PD modeling tools will be crucial toward precision medicine.

Impact of ABCG2 and SLCO1B1 polymorphisms on pharmacokinetics of rosuvastatin, atorvastatin and simvastatin acid in Caucasian and Asian subjects: a class effect?

PURPOSE

Systemic exposure to rosuvastatin is approximately double that of Caucasians in Asian subjects. We investigated whether this pattern of increased exposure exists for other statins.

METHODS

Plasma exposure following single-dose rosuvastatin 20 mg, atorvastatin 40 mg or simvastatin 40 mg was studied in Chinese, Japanese and Caucasian subjects. Plasma concentrations were determined using LC-MS methods. Impact of polymorphisms in SLCO1B1 (T521>C and A388>G) and in ABCG2 (C421>A) on exposure to rosuvastatin, atorvastatin, simvastatin and simvastatin acid was assessed.

RESULTS

Relative to Caucasians, geometric mean area under the curve from time zero to time of last quantifiable concentration was 86 % (90 % confidence interval (CI), 51-130 %) and 55 % (26-91 %) higher for rosuvastatin in Chinese and Japanese subjects, respectively, 53 % (25-88 %) and 69 % (37-108 %) higher for atorvastatin, 23 % (0-52 %) and 12 % (-0.9-39 %) higher for simvastatin and 28 % (5-56 %) and 34 % (10-64 %) higher for simvastatin acid. Geometric mean maximum drug concentration was also proportionally higher for each statin. Polymorphisms in SLCO1B1 T521>C or ABCG2 C421>A were associated with higher exposure to rosuvastatin, atorvastatin and simvastatin acid (but not simvastatin) within a population, but only the ABCG2 C421>A polymorphism contributed towards between-population exposure differences. In individuals carrying wild-type alleles for both SLCO1B1 and ABCG2, area under the plasma concentration-time curve (AUC) still appeared to be higher for rosuvastatin, atorvastatin and simvastatin acid in Chinese and Japanese subjects compared with Caucasians, respectively.

CONCLUSION

Increased exposure to statins in Asian subjects versus Caucasians may represent a more general class phenomenon than previously recognized.

Rosuvastatin pharmacokinetics and pharmacogenetics in Caucasian and Asian subjects residing in the United States

PURPOSE

Systemic exposure to rosuvastatin in Asian subjects living in Japan or Singapore is approximately twice that observed in Caucasian subjects in Western countries or in Singapore. This study was conducted to determine whether pharmacokinetic differences exist among the most populous Asian subgroups and Caucasian subjects in the USA.

METHOD

Rosuvastatin pharmacokinetics was studied in Chinese, Filipino, Asian-Indian, Korean, Vietnamese, Japanese and Caucasian subjects residing in California. Plasma concentrations of rosuvastatin and metabolites after a single 20-mg dose were determined by mass spectrometric detection. The influence of polymorphisms in SLCO1B1 (T521>C [Val174Ala] and A388>G [Asn130Asp]) and in ABCG2 (C421>A [Gln141Lys]) on exposure to rosuvastatin was also assessed.

RESULTS

The average rosuvastatin area under the curve from time zero to time of last quantifiable concentration was between 64 and 84 % higher, and maximum drug concentration was between 70 and 98 % higher in East Asian subgroups compared with Caucasians. Data for Asian-Indians was intermediate to these two ethnic groups at 26 and 29 %, respectively. Similar increases in exposure to N-desmethyl rosuvastatin and rosuvastatin lactone were observed. Rosuvastatin exposure was higher in subjects carrying the SLCO1B1 521C allele compared with that in non-carriers of this allele. Similarly, exposure was higher in subjects carrying the ABCG2 421A allele compared with that in non-carriers.

CONCLUSION

Plasma exposure to rosuvastatin and its metabolites was significantly higher in Asian populations residing in the USA compared with Caucasian subjects living in the same environment. This study suggests that polymorphisms in the SLCO1B1 and ABCG2 genes contribute to the variability in rosuvastatin exposure.

Effects of polymorphisms in ABCG2, SLCO1B1, SLC10A1 and CYP2C9/19 on plasma concentrations of rosuvastatin and lipid response in Chinese patients

AIM

This study examined whether the ABCG2 421C>A polymorphism and variants in other genes potentially related to the pharmacokinetics of rosuvastatin influenced the plasma concentration of rosuvastatin in Chinese patients with hypercholesterolemia.

PATIENTS & METHODS

Overnight fasting blood samples were collected from 291 patients who had received a rosuvastatin 10 mg night-time dose for at least 4 weeks. Plasma concentrations of rosuvastatin and N-desmethyl rosuvastatin were quantified using liquid chromatography tandem mass spectrometry.

RESULTS

In subjects with the ABCG2 421AA genotype (n = 39), the mean plasma concentrations of rosuvastatin and its metabolite were 63 and 41% greater than the values in those with the 421CA genotype (n = 108) and 120 and 99% greater than in those with the 421CC genotype (n = 129). The plasma concentrations of rosuvastatin were associated (r = -0.194; p = 0.001) with the percentage reduction in low-density lipoprotein cholesterol with rosuvastatin, but the association was not significant after adjusting for the ABCG2 421C>A polymorphism. The SLCO1B1 521T>C polymorphism was associated with increased plasma concentrations of rosuvastatin and impaired N-demethylation of rosuvastatin, but had no impact on its lipid-lowering effect. Polymorphisms in CYP2C9, CYP2C19 and SLC10A1 had minimal effects.

CONCLUSION

These findings suggest that the increased plasma concentrations of rosuvastatin in Chinese patients are associated with increased lipid-lowering effects and lower doses of rosuvastatin should be effective in subjects with the ABCG2 421C>A variant.

Evaluation of the pharmacokinetics and drug interactions of the two recently developed statins, rosuvastatin and pitavastatin

INTRODUCTION

Statins are the cornerstone of lipid-lowering therapy to reduce the risk of coronary heart disease. Rosuvastatin and pitavastatin are the two recently developed statins with less potential for drug interaction resulting in improved safety profiles.

AREAS COVERED

This review summarizes the pharmacokinetics and drug interactions of rosuvastatin and pitavastatin. The materials reviewed were identified by searching PubMed for publications using 'rosuvastatin', 'pitavastatin', 'statins', 'pharmacokinetics' and 'drug interaction' as the search terms.

EXPERT OPINION

Rosuvastatin and pitavastatin have favorable pharmacokinetic and safety profiles as their disposition does not depend on or is only marginally influenced by cytochrome P450 (CYP) enzymes, thus potentially reducing the risk of drug-drug interactions of these two statins with other drugs known to inhibit CYP enzymes. However, drug transporters play a significant role in the disposition of rosuvastatin and pitavastatin and drug interactions may occur through these. Genetic polymorphisms in drug transporters may also affect the pharmacokinetics, drug interactions and/or the lipid-lowering effect of these statins to a different extent.

Pharmacokinetic and pharmacodynamic profile of rosuvastatin in patients with end-stage renal disease on chronic haemodialysis

BACKGROUND

Rosuvastatin has been shown to provide effective treatment of dyslipidaemia in patients with end-stage renal disease (ESRD) undergoing haemodialysis, but data from controlled trials are very limited on the pharmacokinetics and pharmacodynamics of rosuvastatin in this population.

OBJECTIVE

The aim of the present study was to better define the pharmacokinetic and pharmacodynamic profiles of repeated doses of rosuvastatin at a starting dose of 10 mg/day in a group of patients with ESRD.

STUDY DESIGN

This was a single-centre, open-label study of rosuvastatin 10 mg daily, given over a 16-day treatment period in patients with ESRD undergoing chronic haemodialysis.

SETTING

The study was carried out at a single site in the USA.

PATIENTS

Patients aged 18-65 years with ESRD who had been on dialysis for ≥ 3 months were eligible for inclusion. Of 12 patients enrolled, 11 were included in the pharmacokinetic and pharmacodynamic analysis and all were included in the safety evaluation. The mean age of patients was 43.9 years (range 24-60 years). Five patients were Caucasian, six were black and one was Hispanic.

INTERVENTION

Patients received an oral dose of rosuvastatin 10 mg once daily in the morning for 16 consecutive days.

MAIN OUTCOME MEASURE

The primary objective was to estimate the degree of rosuvastatin accumulation in plasma by measuring the area under the plasma concentration time curve (AUC) from time zero to 24 h following a single dose of rosuvastatin 10 mg on day 1, and the AUC at steady state on day 15.

RESULTS

Following administration of single and multiple doses, plasma concentrations of rosuvastatin declined in an apparent bi-exponential manner and remained above the limit of assay detection throughout the entire sampling periods on both day 1 and day 15. Steady-state plasma concentrations of rosuvastatin were achieved by day 11. Little accumulation of rosuvastatin after repeated, once-daily dosing was observed; the geometric mean accumulation ratio for rosuvastatin was 1.37 (coefficient of variation = 36.4 %). Clearance of rosuvastatin and its metabolites via dialysis was minimal. Following rosuvastatin 10 mg daily for 16 days, total cholesterol, low-density lipoprotein cholesterol and apolipoprotein B were reduced from baseline by 30.6 %, 38.9 % and 30.6 %, respectively. Rosuvastatin was well tolerated.

CONCLUSION

The degree of rosuvastatin accumulation observed in patients receiving dialysis is similar to that in healthy individuals. The results of the current study suggest that rosuvastatin 10 mg may be administered to patients with ESRD on chronic haemodialysis without need for dose reduction.

Statin dose in Asians: is pharmacogenetics relevant?

Historically the efficacy and safety of statins has mostly been studied in western populations. Few such studies have been carried out in Asians until recent years. These studies revealed interesting similarities and differences for statin use between Asians and Caucasians. One clinically important question subsequently raised is whether Asians need lower statin doses compared with Caucasians. Many practicing physicians believe that statin doses are lower in Asians because of the generally lower bodyweight and BMI. Whether this belief is based on sound scientific evidence needs to be reviewed. Furthermore, since the decision of optimal dose is based on both efficacy and safety, both of which may be impacted by genetic factors, one may ask whether pharmacogenetics plays a role in the dose difference, if such a difference exists. There is a clinical need to critically and comprehensively article the literature to answer these questions, and summarize future directions of research in the field. This article serves the above purpose.

Severe rhabdomyolysis due to rosuvastatin in a liver transplant subject with human immunodeficiency virus and immunosuppressive therapy-related dyslipidemia

Statins are relatively safe first-line agents to use in the setting of dyslipidemia associated with immunosuppressive therapy in subjects undergoing liver transplantation, and also in HIV-infected patients with dyslipidemia due to antiretroviral drugs, especially ritonavir-boosted protease inhibitors. Rosuvastatin, a new statin, has demonstrated higher potency than previously released statins and is not extensively metabolized by the liver P450 system; therefore, the probability of deleterious pharmacokinetic interactions with commonly used immunosuppressants and antiretroviral drugs is reduced. We present the first case of severe rhabdomyolysis in a liver transplant patient receiving rosuvastatin for the treatment of immunosuppressive therapy-related grade IV dyslipidemia, an HIV-infected subject on protease inhibitor-sparing HAART, that resolved after rosuvastatin withdrawal, probably related to interactions between calcineurin inhibitors and hepatic rosuvastatin uptake transporters such as organic anion transporting polypeptides (OATPs).

Race differences: modeling the pharmacodynamics of rosuvastatin in Western and Asian hypercholesterolemia patients

AIM

To evaluate race differences in the pharmacodynamics of rosuvastatin in Western and Asian hypercholesterolemia patients using a population pharmacodynamic (PPD) model generated and validated using published clinical efficacy trials.

METHODS

Published studies randomized trials with rosuvastatin treatment for at least 4 weeks in hypercholesterolemia patients were used for model building and validation. Population pharmacodynamic analyses were performed to describe the dose-response relationship with the mean values of LDL-C reduction (%) from dose-ranging trials using NONMEM software. Baseline LDL-C and race were analyzed as the potential covariates. Model robustness was evaluated using the bootstrap method and the data-splitting method, and Monte Carlo simulation was performed to assess the predictive performance of the PPD model with the mean effects from the one-dose trials.

RESULTS

Of the 36 eligible trials, 14 dose-ranging trials were used in model development and 22 one-dose trials were used for model prediction. The dose-response of rosuvastatin was successfully described by a simple E(max) model with a fixed E(0), which provided a common E(max) and an approximate twofold difference in ED(50) for Westerners and Asians. The PPD model was demonstrated to be stable and predictive.

CONCLUSION

The race differences in the pharmacodynamics of rosuvastatin are consistent with those observed in the pharmacokinetics of the drug, confirming that there is no significant difference in the exposure-response relationship for LDL-C reduction between Westerners and Asians. The study suggests that for a new compound with a mechanism of action similar to that of rosuvastatin, its efficacy in Western populations plus its pharmacokinetics in bridging studies in Asian populations may be used to support a registration of the new compound in Asian countries.

Clinical utility of rosuvastatin and other statins for cardiovascular risk reduction among the elderly

Age is one of the strongest predictors of cardiovascular disease (CVD) risk. Treatment with statins can significantly reduce CVD events and mortality in both primary and secondary prevention. Yet despite the high CVD risk among the elderly, there is underutilization of statins in this population (ie, the treatment-risk paradox). Few studies have investigated the use of statins in the elderly, particularly for primary prevention and, as a result, guidelines for treating the elderly are limited. This is likely due to: uncertainties of risk assessment in older individuals where the predictive value of individual risk factors is decreased; the need to balance the benefits of primary prevention with the risks of polypharmacy, health care costs, and adverse medication effects in a population with decreased life expectancy; the complexity of treating patients with many other comorbidities; and increasingly difficult social and economic concerns. As life expectancy increases and the total elderly population grows, these issues become increasingly important. JUPITER (Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin) is the largest primary prevention statin trial to date and enrolled a substantial number of elderly adults. Among the 5695 JUPITER participants ≥ 70 years of age, the absolute CVD risk reduction associated with rosuvastatin was actually greater than for younger participants. The implications of this JUPITER subanalysis and the broader role of statins among older adults is the subject of this review.

Pharmacokinetics and dosage adjustment in patients with renal dysfunction

INTRODUCTION

Chronic kidney disease is a common, progressive illness that is becoming a global public health problem. In patients with kidney dysfunction, the renal excretion of parent drug and/or its metabolites will be impaired, leading to their excessive accumulation in the body. In addition, the plasma protein binding of drugs may be significantly reduced, which in turn could influence the pharmacokinetic processes of distribution and elimination. The activity of several drug-metabolizing enzymes and drug transporters has been shown to be impaired in chronic renal failure. In patients with end-stage renal disease, dialysis techniques such as hemodialysis and continuous ambulatory peritoneal dialysis may remove drugs from the body, necessitating dosage adjustment.

METHODS

Inappropriate dosing in patients with renal dysfunction can cause toxicity or ineffective therapy. Therefore, the normal dosage regimen of a drug may have to be adjusted in a patient with renal dysfunction. Dosage adjustment is based on the remaining kidney function, most often estimated on the basis of the patient's glomerular filtration rate (GFR) estimated by the Cockroft-Gault formula. Net renal excretion of drug is a combination of three processes: glomerular filtration, tubular secretion and tubular reabsorption. Therefore, dosage adjustment based on GFR may not always be appropriate and a re-evaluation of markers of renal function may be required.

DISCUSSION

According to EMEA and FDA guidelines, a pharmacokinetic study should be carried out during the development phase of a new drug that is likely to be used in patients with renal dysfunction and whose pharmacokinetics are likely to be significantly altered in these patients. This study should be carried out in carefully selected subjects with varying degrees of renal dysfunction. In addition to this two-stage pharmacokinetic approach, a population PK/PD study in patients participating in phase II/phase III clinical trials can also be used to assess the impact of renal dysfunction on the drug's pharmacokinetics and pharmacodynamics.

CONCLUSION

In conclusion, renal dysfunction affects more that just the renal handling of drugs and/or active drug metabolites. Even when the dosage adjustment recommended for patients with renal dysfunction are carefully followed, adverse drug reactions remain common.