Effect of Rosuvastatin on Warfarin Pharmacodynamics and Pharmacokinetics

Efficacy and Safety of Direct Oral Anticoagulants in Patients with Diabetes and Nonvalvular Atrial Fibrillation: Meta-Analysis of Observational Studies

Background

This meta-analysis was performed to compare the efficacy and safety of direct oral anticoagulants (DOACs) with vitamin K antagonists (VKAs) for stroke prevention in real-world patients with diabetes and nonvalvular atrial fibrillation (NVAF) through observational studies.

Methods

PubMed, Embase, and Web of Science databases were searched up to August 2020 for eligible studies. Outputs were presented as risk ratios (RRs) and corresponding 95% confidence intervals (CIs) by using a random-effect model.

Results

Seven observational studies involving 249,794 diabetic NVAF patients were selected. Compared with VKAs, the use of DOACs was associated with significantly reduced risks of stroke (RR = 0.56, 95% CI 0.45-0.70; p < 0.00001), ischemic stroke (RR = 0.61, 95% CI 0.48-0.78; p < 0.0001), stroke or systemic embolism (SSE) (RR = 0.81, 95% CI 0.68-0.95; p = 0.01), myocardial infarction (RR = 0.69, 95% CI 0.55-0.88; p = 0.002), major bleeding (RR = 0.75, 95% CI 0.63-0.90; p = 0.002), intracranial hemorrhage (RR = 0.50, 95% CI 0.44-0.56; p < 0.00001), and major gastrointestinal bleeding (RR = 0.77, 95% CI 0.62-0.95; p = 0.02), and a borderline significant decrease in major adverse cardiac events (RR = 0.87, 95% CI 0.75-1.00; p = 0.05) in NVAF patients with diabetes.

Conclusion

For patients with NVAF and diabetes in real-world clinical settings, DOACs showed superior efficacy and safety profile over VKAs and significantly reduced risks of stroke, ischemic stroke, SSE, myocardial infarction, major bleeding, intracranial hemorrhage, and major gastrointestinal bleeding.

Impact of drug treatment and drug interactions in post-stroke epilepsy

Stroke is a huge burden on our society and this is expected to grow in the future due to the aging population and the associated co-morbidities. The improvement of acute stroke care has increased the survival rate of stroke patients, and many patients are left with permanent disability, which makes stroke the main cause of adult disability. Unfortunately, many patients face other severe complications such as post-stroke seizures and epilepsy. Acute seizures (ASS) occur within 1 week after the stroke while later occurring unprovoked seizures are diagnosed as post-stroke epilepsy (PSE). Both are associated with a poor prognosis of a functional recovery. The underlying neurobiological mechanisms are complex and poorly understood. There are no universal guidelines on the management of PSE. There is increasing evidence for several risk factors for ASS/PSE, however, the impacts of recanalization, drugs used for secondary prevention of stroke, treatment of stroke co-morbidities and antiseizure medication are currently poorly understood. This review focuses on the common medications that stroke patients are prescribed and potential drug interactions possibly complicating the management of ASS/PSE.

Molecular mechanism and thermodynamic study of Rosuvastatin interaction with human serum albumin using a surface plasmon resonance method combined with a multi-spectroscopic, and molecular modeling approach

Rosuvastatin (ROS) is an anti-cholesterol drug belonging to statin drugs. A multi-spectroscopic approach combined with a molecular modeling technique was used to assess ROS association with human serum albumin (HSA). Besides, an HSA immobilized surface plasmon resonance (SPR) chip was used to obtain kinetic parameters (ka, kd, and K_D). Fluorescence quenching titrations revealed that ROS interacts with HSA via a dynamic, exothermic, enthalpy-driven mechanism. Hydrogen bonds and van der Waals interactions as the most prevalent bonding forces contribute to ROS-HSA complex formation. ROS binding to HSA alters HSA conformation. The SPR results indicated that ROS and HSA have a strong interaction possessing an equilibrium constant (K_D) of 1.55 × 10^-8 M at 298 K. A competitive analysis of site markers showed that ROS has a higher tendency to bind to the warfarin binding site (site IIA), which may explain why warfarin has a higher anticoagulant effect in ROS users. FRET analysis indicated that non-radiation energy transfer occurred between ROS and HSA. According to molecular docking studies, ROS prefers binding sites IB and IIA while the ROS-HSA complex stabilizes due to the hydrogen bond and π-π interaction. The presence of hydrogen-bond donors and acceptors, as well as aromatic ROS moieties, facilitates such interactions.

Risk of Gastrointestinal Bleeding on Treatment With Statin Alone or With Concomitant Administration of Warfarin: A Systematic Review and Meta-analysis of 5.3 Million Participants

OBJECTIVE

This study aimed to comprehensively evaluate the risk of gastrointestinal bleeding (GIB) with statin monotherapy or with concomitant warfarin use.

DATA SOURCES

PubMed, Web of Science, and EMBASE (via Scopus) were searched for observational studies that reported the risk of GIB in adults on statin therapy or with concomitant warfarin use until August 28, 2021.

STUDY SELECTION AND DATA EXTRACTION

Observational studies evaluating the risk of GIB in adults (age >18 years) on statin medication or concomitant use with warfarin were included.

DATA SYNTHESIS

In all, 14 studies with a total of 5 235 123 participants, reporting 48 677 GIB events (43 734 from statin users and 4943 from users of statin combined with warfarin), were included in the analyses. The pooled analysis revealed no difference in the risk of GIB with statin monotherapy (relative risk [RR]: 0.65; 95% CI: 0.42-1.02) or concomitant statin + warfarin use (RR: 0.97; 95% CI: 0.91-1.02). Prior use of statin was not associated with GIB risk (RR: 0.88; 95% CI: 0.63-1.22), whereas a shorter duration of statin use (<5 years) was associated with a lower risk of GIB (RR: 0.42; 95% CI: 0.18-0.97).

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This analysis provides strong evidence on the association between statin use (with/without warfarin) and risk of GIB.

CONCLUSION

Statin alone or combined with warfarin was not significantly associated with either an increased or decreased risk of GIB. The GIB risk was significantly lower when statins were used for a short duration (<5 years). The putative relationship between statins and GIB in warfarin users warrant further investigation.

Drug-drug interactions between vitamin K antagonists and statins: a systematic review

PURPOSE

Concomitant use of vitamin K antagonists (VKA) and statins is frequent in cardiovascular patients. However, clinical guidelines on this drug combination are divergent. Therefore, we performed a systematic review to evaluate the effect of statin initiation on coagulation among VKA users.

METHODS

Following the PRISMA guidelines, we applied two broad search strategies for the drug interaction between VKA and statins in both Embase and Pubmed; 8623 unique hits were obtained. In the final sample, eight studies were included.

RESULTS

The most frequently used VKA in the studies was warfarin, while simvastatin was the most commonly initiated statin. All included studies showed a minor increase in the anticoagulant effect of VKA following statin initiation during VKA treatment. The reported increases in mean international normalized ratio (INR) ranged from 0.15-0.65.

CONCLUSION

The anticoagulant effect of statin initiation in patients treated with VKA is likely to be of limited clinical relevance but should be evaluated individually.

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.

The Safety and Efficacy of Rivaroxaban Compared with Warfarin in Patients with Atrial Fibrillation and Diabetes: A Systematic Review and Meta-analysis

AIMS

This meta-analysis was conducted to compare the efficacy and safety of rivaroxaban with warfarin in patients with atrial fibrillation (AF) and diabetes mellitus.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were systematically searched from the establishment of databases up to 15 October 2019. Studies on efficacy and safety outcomes of rivaroxaban and warfarin were included. Efficacy and safety outcomes, including stroke, ischemic stroke, stroke or systemic embolism, myocardial infarction, major adverse cardiac events, major bleeding, intracranial hemorrhage, and major gastrointestinal bleeding were collected for meta-analysis.

RESULTS

Compared with warfarin, rivaroxaban could significantly reduce stroke (risk ratio [RR] 0.77; 95% confidence interval [CI] 0.63-0.95; P = 0.01), ischemic stroke (RR 0.74; 95% CI 0.63-0.87; P = 0.0004), stroke or systemic embolism (RR 0.73; 95% CI 0.60-0.89; P = 0.002), myocardial infarction (RR 0.68; 95% CI 0.56-0.82; P < 0.0001), and major adverse cardiac events (RR 0.71; 95% CI 0.53-0.94; P = 0.02) in patients with AF and diabetes. Moreover, rivaroxaban was associated with a lower risk of major bleeding (RR 0.79; 95% CI 0.65-0.96; P = 0.02), intracranial hemorrhage (RR 0.52; 95% CI 0.39-0.69; P < 0.00001), and major gastrointestinal bleeding (RR 0.74; 95% CI 0.56-0.98; P = 0.04). Similar results were obtained in stratified meta-analysis of cohort studies.

CONCLUSION

Our study suggests a favorable risk-benefit profile of rivaroxaban, with superior efficacy and safety over warfarin in patients with AF and diabetes.

Effects of acid and lactone forms of statins on S-warfarin 7-hydroxylation catalyzed by human liver microsomes and recombinant CYP2C9 variants (CYP2C9.1 and CYP2C9.3)

The inhibition of CYP2C9-mediated warfarin metabolism by acid or lactone forms of statin converted in the body and effects of CYP2C9 genetic variants on their inhibition are not fully understood. Here, the effects of acid and lactone forms of statins on S-warfarin 7-hydroxylation were investigated in vitro. S-Warfarin 7-hydroxylase activities of human liver microsomes (HLMs), recombinant CYP2C9.1 (rCYP2C9.1), and rCYP2C9.3 (Ile359Leu variant) in the presence of statins were determined by high-performance liquid chromatography. Lactone forms of atorvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, and simvastatin inhibited the activity of HLMs more potently than the corresponding acid forms, whereas fluvastatin acid showed stronger inhibition than fluvastatin lactone. When the effects of statins on rCYP2C9 variants were examined, inhibition profiles of acid versus lactone forms of statins except for fluvastatin were similar between rCYP2C9.1 and rCYP2C9.3. However, the degrees of inhibition by atorvastatin lactone, fluvastatin acid, fluvastatin lactone, lovastatin lactone, and pitavastatin lactone (K_i values) were significantly different between these variants. These results indicated that lactone forms of statins other than fluvastatin showed more potent inhibition of CYP2C9-catalyzed S-warfarin 7-hydroxylation than the corresponding acid forms. Furthermore, our results indicated that Ile359Leu substitution in CYP2C9 affected the inhibitory potencies of statins.

A physiologically based pharmacokinetic/pharmacodynamic modeling approach for drug-drug interaction evaluation of warfarin enantiomers with sorafenib

Sorafenib was suggested to cause drug-drug interaction (DDI) with the common anticoagulant, warfarin based on published studies. The inhibition on CYP2C9 enzyme was thought to be the mechanism, but further studies are warranted. Thus, a mechanistic PBPK/PD model for warfarin enantiomers was developed to predict DDI potential with sorafenib, aiming at providing reference for the rational use of both drugs. PBPK models of warfarin enantiomers were constructed by Simcyp software. A mechanistic PK/PD model was built in NONMEM software. PBPK model of sorafenib was fitted via a top-down method. The final PBPK/PD model of warfarin enantiomers was verified and validated by different dosing regimens, ethnicities and genetic polymorphisms, and used to perform DDI simulations between warfarin racemate and sorafenib among general populations and sub-populations with various CYP2C9 and VKORC1 genotypes. Results suggested low DDI risk between warfarin and sorafenib for general populations. Potentially serious consequence was seen for those carrying both CYP2C9 ∗2 and ∗3 and VKORC1 A/A genotypes. This PBPK/PD modeling approach for warfarin enantiomers enabled DDI evaluation with sorafenib. Close monitoring and warfarin dosage adjustment were recommended for patients carrying mutant genotypes. The novel model could be applied to investigate other drugs that may interact with warfarin.

Drug-drug interaction between warfarin and statins: A Danish cohort study

Initiation of statin treatment is suggested to increase the international normalised ratio (INR) among warfarin users. However, available data is limited and conflicting. We conducted a register-based cohort study to evaluate the drug-drug interaction between warfarin and statins. By linking data on INR measurements and filled prescriptions, we identified warfarin users 2000-2015 initiating simvastatin (n = 1363), atorvastatin (n = 165) or rosuvastatin (n = 23). Simvastatin initiation led to an increase in mean INR from 2.40 to 2.71, with INRs peaking after 4 weeks, corresponding to a mean change of 0.32 (95%CI 0.25-0.38). High-dose and low-dose simvastatin led to comparable changes (mean change 0.33 vs 0.29). Initiation of atorvastatin and rosuvastatin lead to INR increases of 0.27 (95%CI 0.12-0.42) and 0.30 (95%CI -0.09-0.69). In conclusion, initiation of simvastatin, atorvastatin or rosuvastatin among warfarin users led to a minor increase in INR. The magnitude of this change is for most patients likely of limited clinical relevance.

Statin use decreases coagulation in users of vitamin K antagonists

PURPOSE

The purpose of the study is to determine the immediate and long-term effect of statins on coagulation in patients treated with vitamin K antagonists (VKAs).

METHODS

We selected patients on VKAs of two Dutch anticoagulation clinics who initiated treatment with a statin between 2009 and 2013. Patients who initiated or stopped concomitant drugs that interact with VKAs or were hospitalised during follow-up were excluded. The VKA dosage (mg/day) after statin initiation was compared with the last VKA dosage before the statin was started. Immediate and long-term differences in VKA dosage (at 6 and 12 weeks) were calculated with a paired student t test.

RESULTS

Four hundred thirty-five phenprocoumon users (mean age 70 years, 60 % men) and 303 acenocoumarol users (mean age 69 years, 58 % men) were included. After start of statin use, the immediate phenprocoumon dosage was 0.02 mg/day (95 % CI, 0.00 to 0.03) lower. At 6 and 12 weeks, these phenprocoumon dosages were 0.03 (95 % CI, 0.01 to 0.05) and 0.07 mg/day (95 % CI, 0.04 to 0.09) lower as compared with the dosage before first statin use. In acenocoumarol users, VKA dosage was 0.04 mg/day (95%CI, 0.01 to 0.07) (immediate effect), 0.10 (95 % CI, 0.03 to 0.16) (at 6 weeks), and 0.11 mg/day (95 % CI, 0.04 to 0.18) (after 12 weeks) lower.

CONCLUSIONS

Initiation of statin treatment was associated with an immediate and long-term minor although statistically significant decrease in VKA dosage in both phenprocoumon and acenocoumarol users, which suggests that statins may have anticoagulant properties.

Mechanism of Drug-Drug Interactions Between Warfarin and Statins

The anticoagulant drug warfarin and the lipid-lowering statin drugs are commonly co-administered to patients with cardiovascular diseases. Clinically significant drug-drug interactions (DDIs) between these drugs have been recognized through case studies for many years, but the biochemical mechanisms causing these interactions have not been explained fully. Previous theories include kinetic alterations in cytochrome P-450-mediated drug metabolism or disturbances of drug-protein binding, leading to anticoagulant activity of warfarin; however, neither the enantioselective effects on warfarin metabolism nor the potential disruption of drug transporter function have been well investigated. This study investigated the etiology of the DDIs between warfarin and statins. Liquid chromatography-mass spectrometry methods were developed and validated to quantify racemic warfarin, 6 of its hydroxylated metabolites, and pure enantiomers of warfarin; these methods were applied to study the role of different absorption, distribution, metabolism, and excretion properties, leading to DDIs. Plasma protein binding displacement of warfarin was performed in the presence of statins using equilibrium dialysis method. Substrate kinetics of warfarin and pure enantiomers were performed with human liver microsomes to determine the kinetic parameters (Km and Vmax) for the formation of all 6 hydroxywarfarin metabolites, inhibition of warfarin metabolism in the presence of statins, was determined. Uptake transport studies of warfarin were performed using overexpressing HEK cell lines and efflux transport using human adenocarcinoma colonic cell line cells. Fluvastatin significantly displaced plasma protein binding of warfarin and pure enantiomers; no other statin resulted in significant displacement of warfarin. All the statins that inhibited the formation of 10-hydroxywarfarin, atorvastatin, pitavastatin, and simvastatin were highly potent compared to other statins; in contrast, only fluvastatin was found to be a potent inhibitor of formation of 7-hydroxy warfarin. Uptake and efflux drug transporters do not play any role in these DDIs. The results showed that DDIs between warfarin and statins are primarily caused by cytochrome P-450 inhibition.

Statin therapy across the lifespan: evidence in major age groups

This review provides needed perspective on statin efficacy and safety in individuals under 40, 40-75, and > 75 years of age. Starting with the 2013 ACC-AHA cholesterol guidelines extensive evidence base on randomized controlled trials (RCTs) we added references in the past 5 years that discussed statin efficacy and safety over the life span. In those under 40, statins are primarily used for treatment of severe hypercholesterolemia, often familial, and they are well tolerated. In middle-aged adults, statins have strong evidence for benefit in primary and secondary prevention trials; however, in primary prevention, a clinician-patient risk discussion should precede statin prescription in order to determine appropriate treatment. In those over 75, issues of statin intensity and net benefit loom large as associated comorbidity, polypharmacy, and potential for adverse effects impact the decision to use statins with RCT data strongest in support of use in secondary prevention. Statin drugs have been studied by RCTs in a large number of individuals. In those groups shown to benefit, statins have reduced the risk of atherosclerotic cardiovascular disease with few side effects as compared to controls. This review has detailed considerations that should occur when statins are given to individuals in different age groups.

Potential statin-drug interactions: prevalence and clinical significance

Background

Statins are cholesterol-lowering drugs widely used for cardiovascular prevention. Although safe when used alone, in combination with other drugs the likelihood of adverse drug reactions increases significantly. The exposure of the Bulgarian population to coprescriptions leading to potential statin-drug interactions is currently unknown.

Objective

The aim of this study was to investigate the incidence of coprescriptions involving statins and to compare the exposure of outpatients and inpatients to potential statin-drug interactions.

Setting

A cardiology clinic of the teaching University hospital in Varna, Bulgaria.

Method

This observational retrospective study examined the medical records of hospitalized patients prescribed a statin in combination with potentially interacting drugs. Patients who entered the hospital with a statin coprescription (considered outpatients) were compared with those coprescribed a statin at discharge from hospital (considered inpatients). Potentially interacting drugs included inhibitors and inducers of cytochrome P450 (CYP) enzymes and drugs of narrow safety margin (coumarin anticoagulants, digitalis).

Main outcome measure

The proportion of patients exposed to statin coprescriptions with potentially interacting drugs at hospital admission and discharge. Secondary outcome measures: laboratory evidence supporting possible statin-drug interactions.

Results

Out of 1641 hospitalized patients examined, 572 were prescribed a statin, either at hospital admission or discharge. Simvastatin was most commonly prescribed and simvastatin-drug coprescription predominated, especially at discharge. The exposure to all potential statin-drug interactions was similar at hospital admission (26.1%) and discharge (24.4%), as was the exposure to statin combinations with CYP inhibitors, 6.4% and 4%, correspondingly. Overall, more coprescriptions were generated, than were eliminated by hospital physicians. Amiodarone was the CYP inhibitor most frequently coprescribed. Of all interacting drugs acenocoumarol was the most commonly found, the proportions of statin-acenocoumarol coprescriptions being roughly the same at hospital entry (11.5%) and discharge (12.4%). In 7 patients out of 69 exposed to the combination, INR was found to be higher than 3, indicating a risk of over-anticoagulation.

Conclusions

Potential statin-drug interactions are common. Although they do not differ between outpatient and inpatient settings, new hazardous coprescriptions are more frequently generated in hospital. Caution is required when acenocoumarol is coprescribed with statins, especially simvastatin.

Rosuvastatin: a highly potent statin for the prevention and management of coronary artery disease

Since the identification of a fungal metabolite that inhibits HMG-CoA reductase in 1976, statins have emerged rapidly as the global leader in pharmacotherapeutics designed to lower low-density lipoprotein cholesterol (LDL-C). In conjunction, practice guidelines have recommended increasingly aggressive measures to improve coronary heart disease (CHD) outcomes by lowering LDL-C. By virtue of unique chemical characteristics, enhanced binding thermodynamics and limited cytochrome P450 3A4 metabolism, rosuvastatin calcium has a safety profile in line with currently marketed statins, but a different efficacy profile. Mirroring this chemical profile, the GALAXY program represents a comprehensive evaluation of the efficacy, safety and cost-effectiveness of rosuvastatin in individuals representing various clinical diagnoses, pathophysiological states and ethnicities. Also results from the Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) study could provide further evidence for the use of rosuvastatin in individuals with traditional and emerging CHD risk factors, such as an elevated high sensitivity C-reactive protein level. This review will provide a comprehensive evaluation of the chemistry, clinical efficacy, safety and tolerability of rosuvastatin, and discuss the future role in the management of CHD and atherosclerosis.

Vitamin K antagonists in heart disease: current status and perspectives (Section III). Position paper of the ESC Working Group on Thrombosis--Task Force on Anticoagulants in Heart Disease

Oral anticoagulants are a mainstay of cardiovascular therapy, and for over 60 years vitamin K antagonists (VKAs) were the only available agents for long-term use. VKAs interfere with the cyclic inter-conversion of vitamin K and its 2,3 epoxide, thus inhibiting γ-carboxylation of glutamate residues at the amino-termini of vitamin K-dependent proteins, including the coagulation factors (F) II (prothrombin), VII, IX and X, as well as of the anticoagulant proteins C, S and Z. The overall effect of such interference is a dose-dependent anticoagulant effect, which has been therapeutically exploited in heart disease since the early 1950s. In this position paper, we review the mechanisms of action, pharmacological properties and side effects of VKAs, which are used in the management of cardiovascular diseases, including coronary heart disease (where their use is limited), stroke prevention in atrial fibrillation, heart valves and/or chronic heart failure. Using an evidence-based approach, we describe the results of completed clinical trials, highlight areas of uncertainty, and recommend therapeutic options for specific disorders. Although VKAs are being increasingly replaced in most patients with non-valvular atrial fibrillation by the new oral anticoagulants, which target either thrombin or FXa, the VKAs remain the agents of choice for patients with atrial fibrillation in the setting of rheumatic valvular disease and for those with mechanical heart valves.

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.

Evaluation of the effect of statin use on the acenocoumarol and phenprocoumon maintenance dose

BACKGROUND

Statins and coumarins are prescribed in combination on a regular basis. Some case reports suggested that statins might affect the dose requirements of coumarins. The aim of the study was to investigate whether acenocoumarol and phenprocoumon maintenance doses are influenced by statin use.

METHODS

The Pre-EU-PACT database was used, which contains information on 471 acenocoumarol and 624 phenprocoumon users. The influence of individual statins on the acenocoumarol and phenprocoumon maintenance dose was investigated by comparing unadjusted and adjusted mean differences of the maintenance dose between statin and non-statin users.

RESULTS

Lower adjusted acenocoumarol dose requirements were observed for patients using atorvastatin, simvastatin, pravastatin, and rosuvastatin. These patients had a reduction in adjusted mean acenocoumarol maintenance dose of 0.11, 0.29, 0.38, and 0.69 mg/day, respectively, compared with a mean adjusted dose of 2.60 mg/day for the patients not using a statin. There was no significant effect of statin use on unadjusted and adjusted phenprocoumon maintenance dose (p=0.23 and p=0.35, respectively).

CONCLUSIONS

Mean acenocoumarol maintenance dosages were decreased when acenocoumarol is co-administered with the different statins. Statin use does not affect phenprocoumon maintenance doses significantly.

Factors associated with statin selection among privately insured commercial and Medicare patients

OBJECTIVES

Given the availability of several statins in the United States, it is important to understand patient characteristics associated with their initiation. We analyzed demographic and clinical factors associated with statin selection among new statin users.

METHODS

This retrospective cohort study examined factors associated with statin selection among patients newly initiated on therapy between 1/1/2007 and 12/31/2007. Commercial and Medicare patient cohorts were evaluated separately and comparisons were made between pravastatin (PS) and other statins including simvastatin (SS), atorvastatin (AS), or rosuvastatin (RS). Multiple logistic regression models were employed to assess factors associated with PS initiation versus other statins.

RESULTS

In commercially insured patients, patients initiating PS were more likely to be older, female, and have diabetes mellitus, liver dysfunction, human immunodeficiency virus (HIV) infection, or hypertension and use calcium channel blockers, protease inhibitors, or additional lipid-modifying agents (p < 0.01 for each comparison). In Medicare-age patients, a higher percentage of PS initiators were aged 75-85, female, had atrial fibrillation, and were prescribed warfarin or triazole antifungals (p < 0.01 for each comparison). Presence of atrial fibrillation or HIV infection, or use of calcium channel blockers or additional lipid-modifying agents was associated with PS initiation compared with AS and SS. Use of warfarin was significantly associated with initiating PS compared with SS, AS, and RS in Medicare-age patients.

CONCLUSION

Older age and female gender were associated with PS initiation. In addition, selected comorbidities and use of certain medications including warfarin or protease inhibitors were associated with PS initiation, which may reflect the tolerability of PS and its reduced risk of significant drug-drug interactions for certain patients. Because this study is a retrospective analysis of US healthcare claims, the findings are limited to only those factors captured within claims data and may not be generalizable to all patient populations in which statin therapy is initiated.

Lack of pharmacokinetic interactions between dapagliflozin and simvastatin, valsartan, warfarin, or digoxin

INTRODUCTION

Coronary heart disease, stroke, and peripheral vascular disease are the most common causes of mortality in patients with type 2 diabetes mellitus (T2DM). The aim of these studies was to assess the potential for pharmacokinetic interaction between dapagliflozin, a sodium glucose co-transporter-2 inhibitor being developed for the treatment of T2DM, and four medications commonly prescribed in patients with T2DM and cardiovascular disease: simvastatin, valsartan, warfarin, and digoxin.

METHODS

Potential pharmacokinetic interactions between 20 mg dapagliflozin, 40 mg simvastatin, or 320 mg valsartan were assessed in an open-label, randomized, five-period, five-treatment, unbalanced crossover study in 24 healthy subjects. In a second study, the effects of steady-state dapagliflozin on the pharmacokinetics of 25 mg warfarin or 0.25 mg digoxin were assessed in an open-label, randomized, two-period, two-treatment crossover study in 30 healthy subjects divided into two cohorts. The potential pharmacodynamic interaction between dapagliflozin and warfarin was also evaluated.

RESULTS

All treatments were well tolerated. Neither simvastatin nor valsartan had any clinically meaningful effect on the pharmacokinetics of dapagliflozin. Dapagliflozin increased the area under the curve for simvastatin, simvastatin acid, and valsartan by approximately 19%, 30%, and 6%, respectively, and decreased the maximum observed plasma concentration of valsartan by approximately 6%. These effects were not considered clinically meaningful. In addition, dapagliflozin had no effect on the pharmacokinetics of either digoxin or warfarin. The pharmacodynamics of warfarin were also unaffected by dapagliflozin.

CONCLUSION

In these studies the co-administration of dapagliflozin and simvastatin, valsartan, warfarin, or digoxin was well tolerated without clinically meaningful drug-drug interaction.

Effect of pitavastatin vs. rosuvastatin on international normalized ratio in healthy volunteers on steady-state warfarin

OBJECTIVE

Statins have been shown to impact international normalized ratio (INR) when coadministered with warfarin. The aim of this study was to assess the effect of pitavastatin compared with rosuvastatin on steady-state pharmacodynamics (PD) of warfarin by measuring INR in healthy adult subjects.

METHODS

Subjects received oral doses of warfarin 5 mg once daily on days 1 through 3. The dose was titrated on days 4 through 9 to reach a steady-state INR of 1.5 to 2.2. Warfarin was continued on days 10 through 21 and pitavastatin 4 mg or rosuvastatin 40 mg was administered once daily on days 14 through 22. After a 14-day washout period, the process was repeated with the alternate statin. STUDY NUMBER: NK-104-4.03US.

RESULTS

For pitavastatin, mean INR changed from 1.73 ± 0.18 (n = 42) on day 14 before starting statin dosing, to 1.78 ± 0.29 (n = 42) on day 22 at treatment end; the difference in INR was not significant (p = 0.219). For rosuvastatin, mean INR increased significantly from 1.74 ± 0.20 (n = 43) at baseline to 1.90 ± 0.30 (n = 43) at treatment end (p < 0.001). Rosuvastatin caused a significantly greater increase in INR than pitavastatin (p < 0.001).

CONCLUSION

Steady-state INR during warfarin treatment did not change significantly when pitavastatin 4 mg was added to the regimen, while a significant increase was observed when rosuvastatin 40 mg was added. The effect of rosuvastatin on INR was significantly larger than the effect of pitavastatin. This study is limited because it was done in healthy volunteers. Further studies in patient populations are needed to better understand the clinical significance of the results.

Drug and dietary interactions of warfarin and novel oral anticoagulants: an update

Clinicians and patients around the world have been intrigued by the concept of developing an oral anticoagulant with a broad therapeutic window and few drug and dietary interactions that can be administered at fixed doses with no or minimal monitoring. The recently approved oral direct thrombin inhibitor dabigatran, along with the emerging oral anti-factor Xa inhibitors, rivaroxaban, apixaban, and edoxaban, have been developed to address many of the shortcomings of warfarin therapy. As warfarin is associated with extensive food and drug interactions, there is also a need to consider such interactions with the new oral anticoagulants. While to date few drug and dietary interactions have been reported with the new oral anticoagulants, it is still early in their development and clinical use cycle. Pharmacokinetic and pharmacodynamic profiles will have to be closely accounted for when determining the likelihood of a potential drug interaction prior to therapy initiation. As the list of drugs and supplements that interact with warfarin is continuously expanding, and the knowledge on drug interactions with the novel oral anticoagulants is still in its infancy, clinicians need to be vigilant when initiating any of these agents or when any changes in the patient's medication profile occur and perform a close screening for potential drug and dietary interactions. The objective of this paper is to give an update on drug and dietary interactions with warfarin and the novel oral anticoagulants, dabigatran, rivaroxaban, apixaban, and edoxaban.

Drug-drug interaction study to assess the effects of multiple-dose pitavastatin on steady-state warfarin in healthy adult volunteers

Warfarin, an antagonist of vitamin K, which inhibits clotting factor synthesis, is prescribed for thrombosis prophylaxis and treatment and is known to have a narrow therapeutic range. Pitavastatin is a potent HMG-CoA reductase inhibitor. In this study, the influence of multiple-dose pitavastatin (4 mg once daily) on steady-state warfarin pharmacodynamic and pharmacokinetic profiles was investigated in 24 healthy male participants whose international normalized ratio (INR) was maintained by individualized doses of warfarin. The ratio of the least squares mean of prothrombin time and INR was 0.989 (90% confidence interval [CI], 0.955-1.023) and 0.993 (0.956-1.209), respectively (test: warfarin + pitavastatin; reference: warfarin only). The geometric mean ratios of C(max) and AUC were 1.034 (90% CI, 0.994-1.075) and 1.066 (1.035-1.099), respectively, for R-warfarin and 1.033 (0.995-1.073) and 1.058 (1.026-1.092), respectively, for S-warfarin. Warfarin pharmacodynamic profiles and pharmacokinetic profiles did not differ between the warfarin monotherapy and the coadministration of pitavastatin and warfarin. No drug-drug interaction between pitavastatin and warfarin was demonstrated.

Rosuvastatin-associated adverse effects and drug-drug interactions in the clinical setting of dyslipidemia

HMG-CoA reductase inhibitors (statins) are the mainstay in the pharmacologic management of dyslipidemia. Since they are widely prescribed, their safety remains an issue of concern. Rosuvastatin has been proven to be efficacious in improving serum lipid profiles. Recently published data from the JUPITER study confirmed the efficacy of this statin in primary prevention for older patients with multiple risk factors and evidence of inflammation. Rosuvastatin exhibits high hydrophilicity and hepatoselectivity, as well as low systemic bioavailability, while undergoing minimal metabolism via the cytochrome P450 system. Therefore, rosuvastatin has an interesting pharmacokinetic profile that is different from that of other statins. However, it remains to be established whether this may translate into a better safety profile and fewer drug-drug interactions for this statin compared with others. Herein, we review evidence with regard to the safety of this statin as well as its interactions with agents commonly prescribed in the clinical setting. As with other statins, rosuvastatin treatment is associated with relatively low rates of severe myopathy, rhabdomyolysis, and renal failure. Asymptomatic liver enzyme elevations occur with rosuvastatin at a similarly low incidence as with other statins. Rosuvastatin treatment has also been associated with adverse effects related to the gastrointestinal tract and central nervous system, which are also commonly observed with many other drugs. Proteinuria induced by rosuvastatin is likely to be associated with a statin-provoked inhibition of low-molecular-weight protein reabsorption by the renal tubules. Higher doses of rosuvastatin have been associated with cases of renal failure. Also, the co-administration of rosuvastatin with drugs that increase rosuvastatin blood levels may be deleterious for the kidney. Furthermore, rhabdomyolysis, considered a class effect of statins, is known to involve renal damage. Concerns have been raised by findings from the JUPITER study suggesting that rosuvastatin may slightly increase the incidence of physician-reported diabetes mellitus, as well as the levels of glycated hemoglobin in older patients with multiple risk factors and low-grade inflammation. Clinical trials proposed no increase in the incidence of neoplasias with rosuvastatin treatment compared with placebo. Drugs that antagonize organic anion transporter protein 1B1-mediated hepatic uptake of rosuvastatin are more likely to interact with this statin. Clinicians should be cautious when rosuvastatin is co-administered with vitamin K antagonists, cyclosporine (ciclosporin), gemfibrozil, and antiretroviral agents since a potential pharmacokinetic interaction with those drugs may increase the risk of toxicity. On the other hand, rosuvastatin combination treatment with fenofibrate, ezetimibe, omega-3-fatty acids, antifungal azoles, rifampin (rifampicin), or clopidogrel seems to be safe, as there is no evidence to support any pharmacokinetic or pharmacodynamic interaction of rosuvastatin with any of these drugs. Rosuvastatin therefore appears to be relatively safe and well tolerated, sharing the adverse effects that are considered class effects of statins. Practitioners of all medical practices should be alert when rosuvastatin is prescribed concomitantly with agents that may increase the risk of rosuvastatin-associated toxicity.

Pharmacokinetics and Pharmacodynamics of Combined use of Lopinavir/Ritonavir and Rosuvastatin in HIV-Infected Patients

Background

Lopinavir/ritonavir-containing antiretro-viral therapy can cause hyperlipidaemia. However, most statins are contraindicated due to drug-drug interactions. Rosuvastatin undergoes minimal metabolism by CYP450, so no CYP450-based interaction with lopinavir/ritonavir is expected. This study explored the lipid-lowering effect of rosuvastatin and assessed the effect of lopinavir/ritonavir on the pharmacokinetics of rosuvastatin and vice versa.

Methods

HIV-infected patients on lopinavir/ritonavir (viral load <400 copies/ml) with total cholesterol (TC) >6.2 mmol/l were treated with rosuvastatin for 12 weeks, starting on 10 mg once daily. If fasting target values (TC<5.0 mmol/l, high-density lipoprotein-cholesterol >1.0 mmol/l, low-density lipoprotein-cholesterol [LDL-c] <2.6 mmol/l and triglycerides <2.0 mmol/l) were not reached, rosuvastatin was escalated to 20 mg or 40 mg at week 4 and 8, respectively. Plasma lopinavir/ritonavir trough levels (Cmin) were determined at week 0, 4, 8 and 12 and rosuvastatin Cmin, at week 4, 8 and 12.

Results

Twenty-two patients completed the study. Mean reductions in TC and LDL-c from baseline to week 4 (on rosuvastatin 10 mg once a day) were 27.6% and 31.8%, respectively. Lopinavir/ritonavir concentrations were not influenced by rosuvastatin ( P=0.44 and 0.26, repeated-measures analysis). Median (interquartile range) rosuvastatin Cmin for 10 mg, 20 mg and 40 mg once daily were 0.97 (0.70–1.5), 2.5 (1.3–3.3) and 5.5 (3.3–8.8) ng/ml, respectively.

Conclusions

Rosuvastatin appeared to be an effective statin in hyperlipidaemic HIV-infected patients. Lopinavir/ritonavir levels were not affected by rosuvastatin, but rosuvastatin levels unexpectedly appeared to be increased 1.6-fold compared with data from healthy volunteers. Until safety and efficacy have been confirmed in larger studies, the combination of rosuvastatin and lopinavir/ritonavir should be used with caution.

[New insights and perspectives in the management of dyslipidemia]

PURPOSE

Recent end point trials of lipid-lowering drugs have shown that patients at very high-risk for coronary disease benefit from treatments that lowers low density lipoprotein cholesterol (LDL cholesterol) plasma levels< or =70 mg/dl and that patients with at least 2 risk factors benefit from LDL cholesterol levels< or =100 mg/dl. Epidemiologic studies have shown that the concentration of high density lipoprotein cholesterol (HDL cholesterol) is a strong, independent, inverse predictor of coronary disease risk. Innovative pharmacological approaches to raise low HDL cholesterol levels are currently of considerable interest, especially for patients with type 2 diabetes or metabolic syndrome.

RESULTS

Rosuvastatin has shown superior efficacy in lowering LDL cholesterol, although evidence of clinical benefit is actually lacking. Ezetimibe is a lipid-lowering drug that inhibits absorption of dietary and biliary cholesterol. Its co-administration with statin has given very interesting results. Niacin is the most effective of currently available options for raising HDL cholesterol, although tolerability can be an issue, with serious side effects such as loss of glucose control and liver toxicity. Flushing may occur in 80% of treated patients. Two CETP inhibitors have shown therapeutical efficacy to raise HDL cholesterol, but clinical benefit remains uncertain.

Results from a rosuvastatin historical cohort study in more than 45 000 Dutch statin users, a PHARMO study

PURPOSE

Clinical benefits of statin therapy are accepted, but their safety profiles have been under scrutiny, particularly for the recently introduced statin, rosuvastatin, relating to serious adverse events involving muscle, kidney and liver. Therefore, a historical cohort study was performed to evaluate the association between rosuvastatin versus other statin use and the incidence of rhabdomyolysis, myopathy, acute renal failure and hepatic impairment.

METHODS

Incident users of rosuvastatin or other statins in 2003-2004 and a cohort of patients not prescribed statins were included from the PHARMO database of >2 million Dutch residents. Cases of hospitalisations for myopathy, rhabdomyolysis, acute renal failure or hepatic impairment were identified for these cohorts. Potential cases were validated through a multi-step process using data obtained from hospital records. Additionally, cases of all cause deaths were identified from certification alone.

RESULTS

In 2003 and 2004, 10,147 incident rosuvastatin users, 37,396 incident other statin users and 99,935 patients without statin prescriptions were included. There were 26 validated outcome events in the three cohorts including one case each of myopathy (other statin group) and rhabdomyolysis (non-treated group). There were no significant differences in the incidence of outcome events between rosuvastatin and other statin users.

CONCLUSION

This study indicated that the number of outcome events is less than 1 per 3000 person years. This study in more than 45,000 Dutch statin users suggests that rosuvastatin does not lead to an increased incidence of rhabdomyolysis, myopathy, acute renal failure or hepatic impairment compared to other statins.