Pharmacokinetics of atorvastatin and its metabolites after single and multiple dosing in hypercholesterolaemic haemodialysis patients

Comprehensive review of statin-intolerance and the practical application of Bempedoic Acid

Statin-intolerance (SI) has prevalence between 8.0 % and 10 %, and muscular complaints are the most common reason for discontinuation. Bempedoic acid (BA), an ATP citrate lyase inhibitor, decreases hepatic generation of cholesterol, upregulates low-density lipoprotein (LDL) receptor expression in the liver, and eventually clears circulating LDL-cholesterol from the blood. Multiple randomized clinical trials studying BA demonstrate a reduction in LDL levels by 17-28 % in SI. The CLEAR OUTCOME trial established significant cardiovascular benefits with BA. A dose of 180 mg/day of BA showed promising results. BA alone or in combination with ezetimibe is US Food and Drug Administration-approved for use in adults with heterozygous familial hypercholesterolemia and/or established atherosclerotic cardiovascular disease. BA reduced HbA1c by 0.12 % (p < 0.0001) in patients with diabetes. Adverse events of BA include myalgia (4.7 %), anemia (3.4 %), and increased aminotransferases (0.3 %). BA can cause up to four times higher risk of gout in those with a previous gout diagnosis or high serum uric acid levels. Reports of increased blood urea nitrogen and serum creatinine were noted. Current evidence does not demonstrate a reduction in deaths from cardiovascular causes. More studies that include a diverse population and patients with both high and low LDL levels should be conducted. We recommend that providers consider BA as an adjunct to statin therapy in patients with a maximally tolerated dosage to specifically target LDL levels.

Novel approach to adherence assessment based on parent drug and metabolite pharmacokinetics: pilot study with spironolactone

AIM

The aim of this study was to evaluate adherence to spironolactone in a group of unselected patients with arterial hypertension by analysis of measured serum spironolactone and canrenone concentrations according to a proposed two-step decision scheme based on pharmacokinetic considerations.

MATERIALS AND METHODS

Simulation of serum concentration-time profiles of spironolactone and canrenone based on population pharmacokinetic parameters described in literature and a body weight-normalized spironolactone dose / canrenone level nomogram derived from a group of adherent patients with conservatively treated primary hyperaldosteronism, were used to create a two-step decision scheme. 71 outpatients treated with spironolactone for resistant hypertension with spironolactone and canrenone serum concentrations measured between 2018 and 2021 were analyzed according to the proposed scheme. We compared our proposed methodology to the standard approach for adherence testing.

RESULTS

With the most sensitive traditional approach to adherence assessment through detectable serum concentrations of spironolactone and/or canrenone, 9 (12.7%) non-adherent patients were identified. With our two-step assessment of adherence, we were able to identify 18 (25.4%) non-adherent patients.

CONCLUSION

Consideration of the pharmacokinetic properties of parental drug and its metabolite led to improved sensitivity in non-adherence detection in patients with arterial hypertension. This approach enables better interpretation of measured spironolactone and canrenone serum concentrations and should be used in clinical practice.

Aldo-keto reductase-7A2 protects against atorvastatin-induced hepatotoxicity via Nrf2 activation

Atorvastatin (ATO), as a cholesterol-lowering drug, was the world's best-selling drug in the early 2000s. However, ATO overdose-induced liver or muscle injury is a threat to many patients, which restricts its application. Previous studies suggest that ATO overdose is accompanied with ROS accumulation and increased lipid peroxidation, which are the leading causes of ATO-induced liver damage. This study is, therefore, carried out to investigate the roles of anti-oxidant pathways and enzymes in protection against ATO-induced hepatotoxicity. Here we show that in ATO-challenged HepG2 cells, the expression levels of transcription factor NFE2L2/Nrf2 (nuclear factor erythroid 2 p45-related factor 2) are significantly upregulated. When Nrf2 is pharmacologically inhibited or genetically inactivated, ATO-induced cytotoxicity is significantly aggravated. Aldo-keto reductase-7A (AKR7A) enzymes, transcriptionally regulated by Nrf2, are important for bioactivation and biodetoxification. Here, we reveal that in response to ATO exposure, mRNA levels of human AKR7A2 are significantly upregulated in HepG2 cells. Furthermore, knockdown of AKR7A2 exacerbates ATO-induced hepatotoxicity, suggesting that AKR7A2 is essential for cellular adaptive response to ATO-induced cell damage. In addition, overexpression of AKR7A2 in HepG2 cells can significantly mitigate ATO-induced cytotoxicity and this process is Nrf2-dependent. Taken together, these findings indicate that Nrf2-mediated AKR7A2 is responsive to high concentrations of ATO and contributes to protection against ATO-induced hepatotoxicity, making it a good candidate for mitigating ATO-induced side effects.

Effects of Administration and Intensity of Statins on Mortality in Patients Undergoing Hemodialysis

(1) Background: Few studies have investigated the association between the intensity of statins and patient survival rates in patients undergoing hemodialysis (HD) as primary outcomes. This study aimed to evaluate patient survival rates according to the intensity of statins using a large sample of patients undergoing maintenance HD. (2) Methods: Data from a national HD quality assessment program were used in this study (n = 53,345). We divided the patients into four groups based on the administration and intensity of statins: Group 1, patients without a prescription of statins (n = 37,944); Group 2, patients with a prescription of a low intensity of statins (n = 700); Group 3, patients with a prescription of a moderate intensity of statins (n = 14,160); Group 4, patients with a prescription of a high intensity of statins (n = 541). (3) Results: Significant differences in baseline characteristics were observed among the four groups. Group 1 had the best patient survival among the four groups in the univariate Cox regression analyses. However, multivariable Cox regression analyses showed that the patient survival rate was higher for Group 3 than for Group 1. Cox regression analyses using data of a balanced cohort showed that, on univariate analyses, the HRs were 0.93 (95% CI, 0.91-0.95, p < 0.001) in Group 2 and 0.95 (95% CI, 0.93-0.96, p < 0.001) in Group 3 compared to that in Group 1. Group 4 had a higher mortality rate than Groups 2 or 3. The results from the cohort after balancing showed a similar trend to those from the multivariable Cox regression analyses. Young age and less comorbidities in Group 1 were mainly associated with favorable survival in Group 1 in the univariate analysis using cohort before balancing. Among the subgroup analyses based on sex, age, presence of diabetes mellitus, and heart disease, most multivariable analyses showed significantly higher patient survival rates in Group 3 than for Group 1. (4) Conclusions: Our study exhibited significant differences in baseline characteristics between the groups, leading to limitations in establishing a robust association between statin intensity and clinical outcomes. However, we conducted various statistical analyses to mitigate these differences. Some results, including multivariable analyses controlling for baseline characteristics and analyses of a balanced cohort using propensity score weighting, indicated improved patient survival in the moderate-intensity statin group compared to non-users. These findings suggest that moderate statin use may be associated with favorable patient survival.

Atorvastatin-mediated inhibition of prenylation of Rab27b and Rap1a in platelets attenuates their prothrombotic capacity and modulates clot structure

Statins inhibit the mevalonate pathway by impairing protein prenylation via depletion of lipid geranylgeranyl diphosphate (GGPP). Rab27b and Rap1a are small GTPase proteins involved in dense granule secretion, platelet activation, and regulation. We analyzed the impact of statins on prenylation of Rab27b and Rap1a in platelets and the downstream effects on fibrin clot properties. Whole blood thromboelastography revealed that atorvastatin (ATV) delayed clot formation time (P < .005) and attenuated clot firmness (P < .005). ATV pre-treatment inhibited platelet aggregation and clot retraction. Binding of fibrinogen and P-selectin exposure on stimulated platelets was significantly lower following pre-treatment with ATV (P < .05). Confocal microscopy revealed that ATV significantly altered the structure of platelet-rich plasma clots, consistent with the reduced fibrinogen binding. ATV enhanced lysis of Chandler model thrombi 1.4-fold versus control (P < .05). Western blotting revealed that ATV induced a dose-dependent accumulation of unprenylated Rab27b and Rap1a in the platelet membrane. ATV dose-dependently inhibited ADP release from activated platelets. Exogenous GGPP rescued the prenylation of Rab27b and Rap1a, and partially restored the ADP release defect, suggesting these changes arise from reduced prenylation of Rab27b. These data demonstrate that statins attenuate platelet aggregation, degranulation, and binding of fibrinogen thereby having a significant impact on clot contraction and structure.

In situbiosensing technologies for an organ-on-a-chip

Thein vitrosimulation of organs resolves the accuracy, ethical, and cost challenges accompanyingin vivoexperiments. Organoids and organs-on-chips have been developed to model thein vitro, real-time biological and physiological features of organs. Numerous studies have deployed these systems to assess thein vitro, real-time responses of an organ to external stimuli. Particularly, organs-on-chips can be most efficiently employed in pharmaceutical drug development to predict the responses of organs before approving such drugs. Furthermore, multi-organ-on-a-chip systems facilitate the close representations of thein vivoenvironment. In this review, we discuss the biosensing technology that facilitates thein situ, real-time measurements of organ responses as readouts on organ-on-a-chip systems, including multi-organ models. Notably, a human-on-a-chip system integrated with automated multi-sensing will be established by further advancing the development of chips, as well as their assessment techniques.

Mechanisms by which statins protect endothelial cells from radiation-induced injury in the carotid artery

Background

The incidental use of statins during radiation therapy has been associated with a reduced long-term risk of developing atherosclerotic cardiovascular disease. However, the mechanisms by which statins protect the vasculature from irradiation injury remain poorly understood.

Objectives

Identify the mechanisms by which the hydrophilic and lipophilic statins pravastatin and atorvastatin preserve endothelial function after irradiation.

Methods

Cultured human coronary and umbilical vein endothelial cells irradiated with 4 Gy and mice subjected to 12 Gy head-and-neck irradiation were pretreated with statins and tested for endothelial dysfunction, nitric oxide production, oxidative stress, and various mitochondrial phenotypes at 24 and 240 h after irradiation.

Results

Both pravastatin (hydrophilic) and atorvastatin (lipophilic) were sufficient to prevent the loss of endothelium-dependent relaxation of arteries after head-and-neck irradiation, preserve the production of nitric oxide by endothelial cells, and suppress the cytosolic reactive oxidative stress associated with irradiation. However, only pravastatin inhibited irradiation-induced production of mitochondrial superoxide; damage to the mitochondrial DNA; loss of electron transport chain activity; and expression of inflammatory markers.

Conclusions

Our findings reveal some mechanistic underpinnings of the vasoprotective effects of statins after irradiation. Whereas both pravastatin and atorvastatin can shield from endothelial dysfunction after irradiation, pravastatin additionally suppresses mitochondrial injury and inflammatory responses involving mitochondria. Clinical follow-up studies will be necessary to determine whether hydrophilic statins are more effective than their lipophilic counterparts in reducing the risk of cardiovascular disease in patients undergoing radiation therapy.

Unknown Organofluorine Mixtures in U.S. Adult Serum:Contribution from Pharmaceuticals?

Organofluorines occur in human serum as complex mixtures of known and unidentified compounds. Human biomonitoring traditionally uses targeted analysis to measure the presence of known and quantifiable per- and polyfluoroalkyl substances (PFAS) in serum, yet characterization of exposure to and quantification of PFAS are limited by the availability of methods and analytical standards. Studies comparing extractable organofluorine (EOF) in serum to measured PFAS using organofluorine mass balance show that measurable PFAS only explain a fraction of EOF in human serum and that other sources of organofluorine may exist. The gap in fluorine mass balance has important implications for human biomonitoring because the total body burden of PFAS cannot be characterized and the chemical species that make up unidentified EOF are unknown. Many highly prescribed pharmaceuticals contain organofluorine (e.g., Lipitor, Prozac) and are prescribed with dosing regimens designed to maintain a therapeutic range of concentrations in serum. Therefore, we hypothesize organofluorine pharmaceuticals contribute to EOF in serum. We use combustion ion chromatography to measure EOF in commercial serum from U.S. blood donors. Using fluorine mass balance, we assess differences in unexplained organofluorine (UOF) associated with pharmaceutical use and compare them with concentrations of organofluorine predicted based on the pharmacokinetic properties of each drug. Pharmacokinetic estimates of organofluorine attributable to pharmaceuticals ranged from 0.1 to 55.6 ng F/mL. Analysis of 44 target PFAS and EOF in samples of commercial serum (n = 20) shows the fraction of EOF not explained by Σ₄₄ PFAS ranged from 15% to 86%. Self-reported use of organofluorine pharmaceuticals is associated with a 0.36 ng F/mL (95% CL: -1.26 to 1.97) increase in UOF, on average, compared to those who report not taking organofluorine pharmaceuticals. Our study is the first to assess sources of UOF in U.S. serum and examine whether organofluorine pharmaceuticals contribute to EOF. Discrepancies between pharmacokinetic estimates and EOF may be partly explained by differences in analytical measurements. Future analyses using EOF should consider multiple extraction methods to include cations and zwitterions. Whether organofluorine pharmaceuticals are classified as PFAS depends on the definition of PFAS.

Enhancing the biopharmaceutical attributes of atorvastatin calcium using polymeric and lipid-polymer hybrid nanoparticles: An approach for atherosclerosis treatment

Atherosclerosis is associated with inflammation in the arteries, a significant cause of heart attacks and strokes. Although statin therapy can reduce the chances of atherosclerotic plaque formation, they need to be administered in high doses due to low systemic bioavailability and encountered with side effects. To overcome these challenges, we developed nanoparticles using biocompatible and biodegradable lipids and polymers for improving systemic drug absorption and therapeutic response. The polymeric nanoparticles were prepared using PLGA and PVA, while hybrid nanoparticles were prepared using PLGA and Phospholipon 90 G. Both nanoparticles were systematically optimized by I-optimal response surface design. The optimum formulation composition exhibited particle size of less than 250 nm, polydispersity index of less than 0.3, entrapment efficiency of more than 70%, and sustained drug release up to 6 h. In vivo pharmacokinetic evaluation in rats indicated multi-fold improvement in the extent of drug absorption (C_max and AUC_total) for atorvastatin from the nanoparticles vis-à-vis the pure drug suspension. In vivo pharmacodynamic studies also indicated the excellent ability of nanoparticles to lower the elevated levels of lipids (total cholesterol, triglycerides, and low-density lipoproteins) and increase the level of high-density lipoproteins as compared to that of the pure drug suspension.

Synthesis Strategies and Medicinal Value of Pyrrole and its Fused Heterocyclic Compounds

For several decades, interest in pyrrole and pyrrolopyrimidine derivatives increases owing to their biological importance, such as anti-tumor, anti-microbial, anti-inflammatory, anti-diabetic, anti-histaminic, anti-malarial, anti-Parkinson, antioxidant and anti-viral, specially recently against COVID-19. These tremendous biological features motivated scientists to discover more pyrrole and fused pyrrole derivatives, owing to the great importance of the pyrrole nucleus as a pharmacophore in many drugs, and motivated us to present this article, highlighting on the different synthetic pathways of pyrrole and its fused compounds specially pyrrolopyrimidine, as well as their medicinal value from 2017 till 2021.

Chronic Renal Failure and Cardiovascular Disease: A Comprehensive Appraisal

Coronary artery disease is highly prevalent in patients with chronic kidney disease. The concomitant renal disease often poses a major challenge in decision making as symptoms, cardiac biomarkers and noninvasive studies for evaluation of myocardial ischemia have different sensitivity and specificity thresholds in this specific population. Moreover, the effectiveness and safety of intervention and medical treatment in those patients is of great doubt as most clinical studies exclude patients with advance CKD. In the present paper, we discuss and review the literature in the diagnosis, treatment and prevention of CAD in the acute and chronic setting, in patients with CKD.

A Novel Statin Compound from Monacolin J Produced Using CYP102A1-Catalyzed Regioselective C-Hydroxylation

Statins inhibit the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMG-CoA reductase), which is the rate-limiting enzyme in cholesterol biosynthesis. Statin therapy reduces morbidity and mortality in those who are at high risk of cardiovascular disease. Monacolin J is a statin compound, which is an intermediate in the lovastatin biosynthesis pathway, in the fungus Aspergillus terreus. It is also found in red yeast rice, which is made by culturing rice with the yeast Monascus purpureus. Monacolin J has a hydroxyl substituent at position C’-8 of monacolin L. Here, a new statin derivative from monacolin J was made through the catalysis of CYP102A1 from Bacillus megaterium. A set of CYP102A1 mutants of monacolin J hydroxylation with high catalytic activity was screened. The major hydroxylated product was C-6′a-hydroxymethyl monacolin J, whose structure was confirmed using LC–MS and NMR analysis. The C-6′a-hydroxymethyl monacolin J has never been reported before. It showed a greater ability to inhibit HMG-CoA reductase than the monacolin J substrate itself. Human liver microsomes and human CYP3A4 also showed the ability to catalyze monacolin J in producing the same product of the CYP102A1-catalyzed reaction. This result motivates a new strategy for the development of a lead for the enzymatic and chemical processes to develop statin drug candidates.

Current Evidence, Challenges, and Opportunities of Physiologically Based Pharmacokinetic Models of Atorvastatin for Decision Making

Atorvastatin (ATS) is the gold-standard treatment worldwide for the management of hypercholesterolemia and prevention of cardiovascular diseases associated with dyslipidemia. Physiologically based pharmacokinetic (PBPK) models have been positioned as a valuable tool for the characterization of complex pharmacokinetic (PK) processes and its extrapolation in special sub-groups of the population, leading to regulatory recognition. Several PBPK models of ATS have been published in the recent years, addressing different aspects of the PK properties of ATS. Therefore, the aims of this review are (i) to summarize the physicochemical and pharmacokinetic characteristics involved in the time-course of ATS, and (ii) to evaluate the major highlights and limitations of the PBPK models of ATS published so far. The PBPK models incorporate common elements related to the physicochemical aspects of ATS. However, there are important differences in relation to the analyte evaluated, the type and effect of transporters and metabolic enzymes, and the permeability value used. Additionally, this review identifies major processes (lactonization, P-gp contribution, ATS-Ca solubility, simultaneous management of multiple analytes, and experimental evidence in the target population), which would enhance the PBPK model prediction to serve as a valid tool for ATS dose optimization.

A Combination of Atorvastatin and Aspirin Enhances the Pro-Regenerative Interactions of Marrow Stromal Cells and Stroke-Derived Monocytes In Vitro

Background and Purpose: Marrow stromal cells (MSCs) are being tested in clinical trials for stroke patients. MSCs appear to promote recovery through secretomes that promote modulation of immune cells, including myeloid phagocytes. Many stroke patients have comorbidities such as metabolic syndrome, hypertension, hypercholesterolemia, and diabetes for which they are prescribed medications that might affect the function of MSCs and monocytes (Mo) when they are administered in stroke patients. We studied the effects of the two most commonly prescribed stroke medications, statin and statin plus aspirin, on the secretomes of MSCs and their modulation of Mo derived from stroke patients.

Methods: Human MSCs, Mo and their co-cultures were exposed to atorvastatin or atorvastatin plus aspirin followed by secretome analysis at 24 h. Monocytes were isolated from healthy controls as well as stroke patients with NIHSS ranging from 11 to 20. Secretome composition was measured using multiplex immunoassay. We used MTT assay to measure proliferation of monocytes. The mixed model was used to analyze experimental data. p-values less than 0.05 were considered significant.

Results: Atorvastatin and aspirin combination increased the release of IL-1RA from stroke Mo. In MSCs, atorvastatin and aspirin combination reduced the release of pro-inflammatory cytokines such as IL-6, IL-8, MCP-1 and IFN-γ. Atorvastatin alone reduced the release of IL-6, IL-8 and MCP-1 from co-cultures of stroke monocytes and MSCs. Combination of atorvastatin and aspirin had additive effect on reducing the secretion of IL-6 from co-cultures of stroke Mo and MSCs.

Conclusion: Atorvastatin, alone and in combination with aspirin can promote anti-inflammatory effect by modulating the secretome profile of Mo and MSCs. Our results suggest that stroke trials involving the use of intravenous MSCs should consider the effect of aspirin and atorvastatin, both of which are administered to the majority of hospitalized ischemic stroke patients.

Sensitive, High-Throughput Liquid Chromatography-Tandem Mass Spectrometry Analysis of Atorvastatin and Its Pharmacologically Active Metabolites in Serum for Supporting Precision Pharmacotherapy

The antihyerlipidemic drug atorvastatin (ATR) is used worldwide as part of the strategy to prevent cardiovascular events. The high prevalence of patient nonadherence remains an important challenge which could be addressed efficiently by precision pharmacotherapy based on therapeutic drug monitoring (TDM). ATR is metabolized to pharmacologically active metabolites, and evidence shows that the sums of ATR acid and lactone form concentrations (ATR + ATRL), or of ATR and hydroxylated metabolites (ATR + MET) should be assayed. A method is presented for the analysis of these substances in serum. Method validation included the estimation of the quantitative relationship between the concentrations and the standard deviations (SD), which supports the optimal incorporation of TDM results into nonparametric pharmacokinetic models. The concentrations of the analytes were evaluated in human subjects receiving ATR. The method's performance improved by taking the sums of acid and lactone concentrations into account. The concentration-SD relationship was linear, and we recommend applying Theil's regression for estimating the assay error. All analytes could be detected by 2 h post dose in the samples of human subjects. The changes in metabolite/parent drug concentration ratios in time depended on the dose. The method is suitable for the TDM of ATR with a focus on precision pharmacotherapy.

Evaluation of potential drug interactions with sodium zirconium cyclosilicate: a single-center, open-label, one sequence crossover study in healthy adults

Background

Sodium zirconium cyclosilicate (SZC; formerly ZS-9) is an oral potassium binder for the treatment of hyperkalemia in adults. SZC acts in the gastrointestinal tract and additionally binds hydrogen ions in acidic environments like the stomach, potentially transiently increasing gastric pH and leading to drug interactions with pH-sensitive drugs. This study assessed potential pharmacokinetic (PK) interactions between SZC and nine pH-sensitive drugs.

Methods

In this single-dose, open-label, single-sequence cross-over study in healthy adults, amlodipine, atorvastatin, clopidogrel, dabigatran, furosemide, glipizide, levothyroxine, losartan or warfarin were each administered alone and, following a washout interval, with SZC 10 g. Maximum plasma concentration (C_max), area under the plasma concentration–time curve from 0 to the last time point (AUC_0–t) and AUC extrapolated to infinity (AUC_inf) were evaluated. No interaction was concluded if the 90% confidence interval for the geometric mean ratio (SZC coadministration versus alone) of the PK parameters was within 80–125%.

Results

During SZC coadministration, all PK parameters for amlodipine, glipizide, levothyroxine and losartan showed no interaction, while reductions in clopidogrel and dabigatran C_max, AUC_0–t and AUC_inf (basic drugs) were <50% and increases in atorvastatin, furosemide and warfarin C_max (acidic drugs) exceeded the no-interaction range by ˂2-fold.

Conclusions

SZC coadministration was associated with small changes in plasma concentration and exposure of five of the nine drugs evaluated in this study. These PK drug interactions are consistent with transient increases in gastric pH with SZC and are unlikely to be clinically meaningful.

Evaluation of Orally Administered Atorvastatin on Plasma Lipid and Biochemistry Profiles in Hypercholesterolemic Hispaniolan Amazon Parrots (Amazona ventralis)

Atorvastatin is a synthetic statin administered in its active form and used for the treatment of dyslipidemias. In the current study, the effects of atorvastatin were evaluated on plasma lipid profiles and the potential for adverse effects after once daily PO dosing of atorvastatin for 30 days in Hispaniolan Amazon parrots (Amazona ventralis). Sixteen adult parrots (10 female, 6 male) with hypercholesterolemia were used for this study. Birds were assigned to 2 groups (treatment and control) of 8 parrots each (3 male, 5 female) after balancing for age, sex, originating institution, and baseline plasma cholesterol values. Compounded atorvastatin oral suspension (10 mg/kg) was administered PO once daily via gavage into the crop. Equivalent volumes of placebo suspension were administered to the control group. Plasma biochemistry and plasma lipid profile analysis (total cholesterol, high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], and triglycerides [TGs]) were analyzed on days 0, 14, and 30. Plasma samples and HDL-C fractions were evaluated for cholesterol and TG concentrations via enzymatic assays. Subtraction of HDL-C values from total cholesterol yielded the non-HDL-C concentration for each bird. Birds were routinely assessed for appetite, activity, and urofeces. Plasma atorvastatin concentrations were obtained from 7 of 8 birds in the treatment group from banked samples. Those samples were obtained on days 14 and 30, with drug administration 6 to 8 hours before collection. No significant differences were observed in total cholesterol, HDL-C, non-HDL-C, or TG between treatment and control groups at days 0, 14, and 30. Plasma atorvastatin concentrations were variable on day 14 (0.54-5.41 ng/ mL for 6 of 7 samples, with 1 outlier of 307 ng/mL) and on day 30 (0.79-6.74 ng/mL). No adverse effects were noted in any of the birds during the study period. When dosed PO at 10 mg/kg once daily, atorvastatin did not result in significant changes to plasma lipid profiles (eg, lowering of plasma total or non-HDL-C concentrations) at any time point during this study. Future studies to investigate pharmacokinetic and pharmacodynamic properties of atorvastatin in parrots may require increased doses and/or frequency of administration.

A functional long-term 2D serum-free human hepatic in vitro system for drug evaluation

Human in vitro hepatic models generate faster drug toxicity data with higher human predictability compared to animal models. However, for long-term studies, current models require the use of serum and 3D architecture, limiting their utility. Maintaining a functional long-term human in vitro hepatic culture that avoids complex structures and serum would improve the value of such systems for preclinical studies. This would also enable a more straightforward integration with current multi-organ devices to study human systemic toxicity to generate an alternative model to chronic animal evaluations. A human primary hepatocyte culture system was characterized for 28 days in 2D and serum-free defined conditions. Under the studied conditions, human primary hepatocytes maintained their characteristic morphology, hepatic markers and functions for 28 days. The acute and chronic administration of known drugs validated the sensitivity of the system for drug testing. This human 2D model represents a realistic system to evaluate hepatic function for long-term drug studies, without the need of animal serum, confounding variable in most models, and with less complexity and resultant cost compared to most 3D models. The defined culture conditions can easily be integrated into complex multi-organ in vitro models for studying systemic effects driven by the liver function for long-term evaluations.

Effects of Green Tea Extract on Atorvastatin Pharmacokinetics in Healthy Volunteers

BACKGROUND AND OBJECTIVES

Green tea catechins were recently reported to inhibit drug transporters such as organic anion-transporting polypeptides (OATPs) and metabolic enzymes, affecting the bioavailability of many drugs. This study aimed to evaluate the clinical significance of the effects of different doses of green tea extract on the pharmacokinetic parameters of atorvastatin and to rationalize the associated interaction mechanism.

METHODS

A randomized, double-blind, three-phase crossover study involving 12 healthy volunteers was performed. Participants received a single dose of atorvastatin 40 mg alone (control group), atorvastatin 40 mg plus a capsule containing 300 mg of dry green tea extract, or atorvastatin 40 mg plus a capsule containing 600 mg of dry green tea extract. Plasma samples taken from the volunteers were analyzed for atorvastatin using liquid chromatography-tandom mass spectrometry (LC/MS/MS).

RESULTS

Compared to atorvastatin alone, the administration of 300 mg or 600 mg of the green tea extract along with atorvastatin decreased the peak plasma concentration (C_max) of atorvastatin by 25% and 24%, respectively (P < 0.05), and the area under the plasma concentration-time curve (AUC_0-∞) of atorvastatin by 24% and 22%, respectively (P < 0.05). Additionally, administration of 300 mg or 600 mg of the green tea extract increased the apparent oral clearance (CL/F) of atorvastatin by 31% and 29%, respectively. The time to C_max (T_max) and the elimination half-life (t_1/2) of atorvastatin did not differ among the three phases. The effects of 600 mg of the green tea extract on the pharmacokinetic parameters of atorvastatin were not significantly different from the effects of 300 mg of the green tea extract.

CONCLUSION

Green tea extract decreases the absorption but not the elimination of atorvastatin, possibly by inhibiting OATP, albeit not in a dose-dependent manner. Coadministration of green tea extract with atorvastatin may necessitate the monitoring of the plasma concentration of atorvastatin in clinical practice.

Association between individual cholesterol and proteinuria response and exposure to atorvastatin or rosuvastatin

AIM

The PLANET trials showed that atorvastatin 80 mg but not rosuvastatin at either 10 or 40 mg reduced urinary protein to creatinine ratio (UPCR) at similar effects on LDL-cholesterol. However, individual changes in both UPCR and LDL-cholesterol during treatment with these statins varied widely between patients. This inter-individual variability could not be explained by patients' physical or biochemical characteristics. We assessed whether the plasma concentrations of both statins were associated with LDL-cholesterol and UPCR response.

MATERIALS AND METHODS

The PLANET trials randomized patients with a UPCR of 500-5000 mg/g and fasting LDL-cholesterol >2.33 mmol/L to a 52-week treatment with atorvastatin 80 mg, rosuvastatin 10 mg or 40 mg. For the current analysis, patients with available samples at week 52 and treatment compliance >80% by pill count were included (N = 295). The main outcome measurements were percentage change in UPCR and absolute change in LDL-cholesterol (delta LDL) from baseline to week 52.

RESULTS

Median (interquartile range) plasma concentration at week 52 for atorvastatin 80 mg was 3.9 ng/mL (IQR: 2.1 to 8.7), for rosuvastatin 10 mg 1.0 ng/mL (IQR: 0.7 to 2.0) and for rosuvastatin 40 mg 3.5 ng/mL (IQR: 2.0 to 6.8). Higher plasma concentration of statin was associated with larger LDL-cholesterol reductions at week 52 [rosuvastatin r = -0.40 (P < .001); atorvastatin r = -0.28 (P = .006)]. The plasma concentration of both statins did not correlate with UPCR change [rosuvastatin r = 0.07 (P = .30); atorvastatin r = 0.16 (P = .13)].

CONCLUSIONS

Individual variation in plasma concentrations of rosuvastatin and atorvastatin was associated with LDL-cholesterol changes in patients. The individual variation in UPCR change was not associated with the plasma concentration of both statins.

Optimization of Timing and Times for Administration of Atorvastatin-Pretreated Mesenchymal Stem Cells in a Preclinical Model of Acute Myocardial Infarction

Our previous studies showed that the combination of atorvastatin (ATV) and single injection of ATV-pretreated mesenchymal stem cells (MSCs) (ATV -MSCs) at 1 week post-acute myocardial infarction (AMI) promoted MSC recruitment and survival. This study aimed to investigate whether the combinatorial therapy of intensive ATV with multiple injections of ATV -MSCs has greater efficacy at different stages to better define the optimal strategy for MSC therapy in AMI. In order to determine the optimal time window for MSC treatment, we first assessed stromal cell-derived factor-1 (SDF-1) dynamic expression and inflammation. Next, we compared MSC recruitment and differentiation, cardiac function, infarct size, and angiogenesis among animal groups with single, dual, and triple injections of ATV -MSCs at early (Early1, Early2, Early3), mid-term (Mid1, Mid2, Mid3), and late (Late1, Late2, Late3) stages. Compared with AMI control, intensive ATV significantly augmented SDF-1 expression 1.5∼2.6-fold in peri-infarcted region with inhibited inflammation. ATV -MSCs implantation with ATV administration further enhanced MSC recruitment rate by 3.9%∼24.0%, improved left ventricular ejection fraction (LVEF) by 2.0%∼16.2%, and reduced infarct size in all groups 6 weeks post-AMI with most prominent improvement in mid groups and still effective in late groups. Mechanistically, ATV -MSCs remarkably suppressed inflammation and apoptosis while increasing angiogenesis. Furthermore, triple injections of ATV -MSCs were much more effective than single administration during early and mid-term stages of AMI with the best effects in Mid3 group. We conclude that the optimal strategy is multiple injections of ATV -MSCs combined with intensive ATV administration at mid-term stage of AMI. The translational potential of this strategy is clinically promising. Stem Cells Translational Medicine 2019;8:1068-1083.

Atorvastatin induces mitochondrial dysfunction and cell apoptosis in HepG2 cells via inhibition of the Nrf2 pathway

Atorvastatin (ATO) is a 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor widely used to treat hypercholesterolemia. However, clinical application is limited by potential hepatotoxicity. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a master regulator of cellular antioxidants, and oxidative stress is implicated in statin-induced liver injury. This study investigated mechanisms of ATO-induced hepatotoxicity and potential mitigation by Nrf2 signaling. ATO reduced Nrf2 and antioxidant enzyme superoxide dismutase-2 (SOD2) expression in human hepatocarcinoma HepG2 cells. ATO also induced concentration-dependent HepG2 cell toxicity, reactive oxygen species (ROS) accumulation, and mitochondrial dysfunction as evidenced by decreased mitochondrial membrane potential (MMP) and cellular adenosine triphosphate (ATP). Further, ATO induced mitochondria-dependent apoptosis as indicated by increased Bax/Bcl-2 ratio, cleaved caspase-3, mitochondrial cytochrome c release and Annexin V-fluorescein isothiocyanate/propidium iodide staining. Tert-butylhydroquinone enhanced Nrf2 and SOD2 expression, and partially reversed ATO-induced cytotoxicity, ROS accumulation, MMP reduction, ATP depletion and mitochondria-dependent apoptosis. In conclusion, the present study demonstrates that ATO induces mitochondrial dysfunction and cell apoptosis in HepG2 cells, at least in part, via inhibition of the Nrf2 pathway. Nrf2 pathway activation is a potential prevention for ATO-induced liver injury.

Atorvastatin increases the production of proinflammatory cytokines and decreases the survival of Escherichia coli-infected mice

To assess whether the immunosuppressive effects of atorvastatin outweigh its antibacterial ones in an infection, mice were infected with Escherichia coli and administered atorvastatin; survival rates were then monitored. Mice treated with atorvastatin post-infection showed a remarkable decrease in their survival rate. On the other hand, the higher the level of serum IFN-γ in the infected mice treated with atorvastatin, the lower was the survival rate. Levels of IL-4 were markedly depressed in all groups infected with E. coli and treated with atorvastatin. Since atorvastatin inhibits IFN-γ expression in the absence of bacterial infection, we examined whether bacterial lipopolysaccharide (LPS) was the element capable of overriding this inhibition. Mouse peripheral blood mononuclear cells were treated with atorvastatin and lipopolysaccharide ex vivo then proinflammatory (IFN-γ, TNFα, IL-6) and prohumoral/regulatory (IL-4, IL-13, IL-10) cytokine levels were analyzed in culture supernatants. While proinflammatory cytokine levels were decreased upon treatment with atorvastatin alone, their levels were markedly elevated by treatment with LPS, bacterial lysate or bacterial culture supernatant. On the other hand, atorvastatin exerted an inhibitory effect on production of the prohumoral/regulatory cytokines. Our data indicates that any consideration for statins as antimicrobial treatment should assess the possible adverse outcomes.

High concentrations of atorvastatin reduce in-vitro function of conventional T and regulatory T cells

Regulatory T cells (T_regs ) modulate the magnitude of immune responses and possess therapeutic potential in an array of immune diseases. Statins reduce the activation and proliferation of conventional T cells (T_cons ), and they seem to up-regulate the frequency and function of T_regs . However, there is a lack of simultaneous evaluation of the in-vitro effect of statins on the functional profile of T_regs versus T_cons . Herein, magnetically purified T_cons and T_regs were stimulated with CD3/CD28/interleukin (IL)-2 in the presence of atorvastatin (ATV) at 1 or 10 µM. The suppressive function of T_regs , the expression of markers associated with T_reg function, activation levels, cytokine production and calcium flux in both subpopulations were assessed by flow cytometry. ATV had no cytotoxic effect on T cells at the concentrations used. Interestingly, 10 µM ATV hampered the suppressive capacity of T_regs . Moreover, this higher concentration reduced the expression of forkhead box protein 3 (FoxP3), cytotoxic T lymphocyte antigen (CTLA-4) and programmed death 1 (PD-1). In T_cons , ATV at 10 µM decreased PD-1 and CD45RO expression. The expression of CD25, CD69, CD95, CD38, CD62L, CCR7 and perforin was not affected in both subpopulations or at any ATV concentrations. Remarkably, 10 µM ATV increased the percentage of tumour necrosis factor (TNF)-α-producing T_regs . Although there was a reduction of calcium flux in T_cons and T_regs , it was only significant in 10 µM ATV-treated T_cons . These results suggested that 10 µM ATV affects the cellular functions of both populations; however, this concentration particularly affected several aspects of T_reg biology: its suppressive function, cytokine production and expression of T_reg -specific markers.

Statin use and histopathological change in patients with non-alcoholic fatty liver disease: a systematic review and meta-analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver disease. The primary treatment of NAFLD by statins has not been clearly elucidated.

Objectives

To evaluate the effectiveness of statin use in patients with biopsy-proven NAFLD or non-alcoholic steatohepatitis on the change in liver histology.

Methods

We searched MEDLINE, Scopus, Google Scholar, and the Cochrane Central Register of Controlled Trials for clinical trials and observational studies investigating the effects of statins on histological change regardless of type or dosage from inception to December 2015. Random-effect model meta-analyses were used to compute changes in outcomes of interest. The study protocol was registered in advance with the International Prospective Register of Systematic Reviews (PROSPERO 2016 CRD42016033132).

Results

We identified 6 studies (111 patients), representing 5 cohort studies and 1 randomized controlled clinical trial. There was significant decrease in steatosis grading with a standardized mean difference of –2.580 (95% confidence interval [CI] –4.623 to –0.536; P = 0.013) and NAFLD activity score standardized mean difference of –1.488 (95% CI –2.506 to –0.471; P = 0.004). However, there was no significant change in fibrosis stage (0.156; 95% CI –0.553 to 0.865; P = 0.667).

Conclusions

Statin use can possibly reduce the extent of steatohepatitis but not the stage of fibrosis. Further randomized controlled studies to assess histological evidence with adequate sample size and duration are required in order to establish the role of statin as a primary treatment of NAFLD.

Statin treatment reduces matrix degradation capacity of proinflammatory polarized macrophages

BACKGROUND AND AIMS

Macrophages are versatile immune cells involved in tissue degradation and remodeling. Proinflammatory macrophages have the highest capacity of matrix degradation and proteolysis. Within atherosclerotic lesions, proinflammatory macrophages are associated with unstable plaques. Statins have been demonstrated to increase plaque stability. Possible changes of polarized macrophage tissue degradation behavior under statin treatment are currently unknown.

METHODS

Polarized macrophages were tested in vitro for matrix degradation capacity with or without statin treatment.

RESULTS

Proinflammatory macrophages show high matrix degradation capacity, which is lost after statin treatment. Statin concentrations were within a physiological range and did not influence overall macrophage polarization. Proinflammatory macrophages showed however a loss of filopodia where activators of MMPs are located. Loss of matrix degradation in proinflammatory macrophages was associated with changes of MMP14 activation and loss of uPAR localization at filopodia. Supplementation of mevalonate restored localization of uPAR to cellular protrusions and matrix degradation capacity.

CONCLUSION

Statins reduce the matrix degradation potential of proinflammatory macrophages by reducing uPAR localization to cellular filopodia and reducing intracellular MMP14 activation.

Atorvastatin inhibits osteoclastogenesis and arrests tooth movement

INTRODUCTION

In addition to their cholesterol-lowering effects, the statin class of drugs appears to enhance osteogenesis and suppress bone resorption, which could be a clinical concern during orthodontic treatment. In this animal study, we aimed to determine whether atorvastatin (ATV) affects orthodontic tooth movement (OTM) through osteoclast inhibition. Furthermore, we analyzed the potential adverse effects of ATV on long-bone turnover and endochondral ossification.

METHODS

Rats were administered ATV (15 mg/kg) or saline solution via gavage (n = 12 animals/group), starting 2 weeks before initial OTM. Tooth displacement was measured after 7, 14, and 21 days. Histologic sections of the maxilla and femur were obtained after 14 and 21 days of OTM and stained (hematoxylin and eosin; TRAP assay) for histomorphometric analysis.

RESULTS

ATV was associated with significant (P <0.05) reductions in OTM and osteoclast counts. Independently of drug administration, OTM increased the number of osteoclasts and reduced the bone-volume ratio compared with the control maxillae without OTM. Long-term statin administration did not appear to affect femoral endochondral ossification.

CONCLUSIONS

This experimental study showed that the long-term use of ATV can significantly promote osteoclast inhibition and slow the OTM in the first week in rats. Under physiologic conditions, the drug did not affect bone turnover and endochondral ossification.

Specific rescue by ortho-hydroxy atorvastatin of cortical GABAergic neurons from previous oxygen/glucose deprivation: role of pCREB

The statin atorvastatin (ATV) given as a post-treatment has been reported beneficial in stroke, although the mechanisms involved are not well understood so far. Here, we investigated in vitro the effect of post-treatment with ATV and its main bioactive metabolite ortho-hydroxy ATV (o-ATV) on neuroprotection after oxygen and glucose deprivation (OGD), and the role of the pro-survival cAMP response element-binding protein (CREB). Post-OGD treatment of primary cultures of rat cortical neurons with o-ATV, but not ATV, provided neuroprotection to a specific subset of cortical neurons that were large and positive for glutamic acid decarboxylase (large-GAD⁽⁺⁾ neurons, GABAergic). Significantly, only these GABAergic neurons showed an increase in phosphorylated CREB (pCREB) early after neuronal cultures were treated post-OGD with o-ATV. We found that o-ATV, but not ATV, increased the neuronal uptake of glutamate from the medium; this provides a rationale for the specific effect of o-ATV on pCREB in large-GABAergic neurons, which have a higher ratio of synaptic (pCREB-promoting) vs extrasynaptic (pCREB-reducing) N-methyl-D-aspartate (NMDA) receptors (NMDAR) than that of small-non-GABAergic neurons. When we pharmacologically increased pCREB levels post-OGD in non-GABAergic neurons, through the selective activation of synaptic NMDAR, we observed as well long-lasting neuronal survival. We propose that the statin metabolite o-ATV given post-OGD boosts the intrinsic pro-survival factor pCREB in large-GABAergic cortical neurons in vitro, this contributing to protect them from OGD.

Clearance of cardiovascular medications during hemodialysis

PURPOSE OF REVIEW

To review the current understanding of hemodialysis-mediated clearance of commonly used cardiovascular medications.

RECENT FINDINGS

Although cardiovascular drug dialyzability is poorly understood, many drug classes appear to include agents with substantially different degrees of dialyzability. Recent data suggest that more readily dialyzable beta-blockers associate with higher short-term mortality in patients initiating these drugs when on hemodialysis. Although this relationship was not observed in a later study with angiotensin-converting enzyme inhibitors of varying dialyzability, studies of this kind are currently limited by pharmacokinetic data that are either incomplete or no longer applicable to modern hemodialysis procedures.

SUMMARY

There are substantial deficits in our understanding of cardiovascular medication dialyzability, which relates in large part to advances in the process of hemodialysis that have rendered older studies of dialyzability irrelevant. The importance of cardiovascular disease in patients receiving hemodialysis demands a better understanding of the effect hemodialysis exerts on cardiovascular drug pharmacokinetics.

Results of a Doravirine-Atorvastatin Drug-Drug Interaction Study

Doravirine is a novel, highly potent, nonnucleoside reverse transcriptase inhibitor that is administered once daily and that is in development for the treatment of HIV-1 infection. In vitro and clinical data suggest that doravirine is unlikely to cause significant drug-drug interactions via major drug-metabolizing enzymes or transporters. As a common HIV-1 infection comorbidity, hypercholesterolemia is often treated with statins, including the commonly prescribed atorvastatin. Atorvastatin is subject to drug-drug interactions with cytochrome P450 3A4 (CYP3A4) inhibitors. Increased exposure due to CYP3A4 inhibition may lead to serious adverse events (AEs), including rhabdomyolysis. Furthermore, atorvastatin is a substrate for breast cancer resistance protein (BCRP), of which doravirine may be a weak inhibitor; this may increase atorvastatin exposure. The potential of doravirine to affect atorvastatin pharmacokinetics was investigated in a two-period, fixed-sequence study in healthy individuals. In period 1, a single dose of atorvastatin at 20 mg was administered followed by a 72-h washout. In period 2, doravirine at 100 mg was administered once daily for 8 days, with a single dose of atorvastatin at 20 mg concomitantly being administered on day 5. Sixteen subjects were enrolled, and 14 completed the trial; 2 discontinued due to AEs unrelated to the treatment. The atorvastatin area under the curve from time zero to infinity was similar with and without doravirine (geometric mean ratio [GMR] for doravirine-atorvastatin/atorvastatin, 0.98; 90% confidence interval [CI], 0.90 to 1.06), while the maximum concentration decreased by 33% (GMR for doravirine-atorvastatin/atorvastatin, 0.67; 90% CI, 0.52 to 0.85). These changes were deemed not to be clinically meaningful. Both of the study drugs were generally well tolerated. Doravirine had no clinically relevant effect on atorvastatin pharmacokinetics in healthy subjects, providing support for the coadministration of doravirine and atorvastatin.

Effect of the interaction between atorvastatin and selective serotonin reuptake inhibitors on the blood redox equilibrium

Cardiovascular disease and depression often occur simultaneously in the same patient. Long-term polypharmacotherapy can lead to drug-induced oxidative stress. Data concerning the effects of concomitant treatment with atorvastatin and selective serotonin reuptake inhibitors (SSRIs) are lacking. The aim of the present study was to examine oxidative stress parameters in the blood of rats after 28 days treatment with atorvastatin combined with fluoxetine or paroxetine. The study was carried out on male Wistar rats weighing 200-250 g. Aqueous solutions of atorvastatin (10 mg/kg), fluoxetine (10 mg/kg) and paroxetine (10 mg/kg) were injected once a day for 28 days, separately or concomitantly. The activity of glutathione peroxidase (GPX) was determined in the whole blood, whereas the activity of glutathione reductase (GR) and the total antioxidant status (TAS) were determined in the serum. The results demonstrated that concomitant administration of atorvastatin with fluoxetine caused an increase in the GPX activity and the TAS. Atorvastatin administered to rats with paroxetine increased the activities of GPX and GR. In the groups of rats receiving atorvastatin or SSRIs separately, no statistically significant changes in the investigated parameters were observed. The changes that were detected may indicate an increase in endogenous antioxidant levels during the concomitant application of atorvastatin with SSRIs and thus a drug-drug interaction having an effect on the blood redox equilibrium.

The independent contribution of miRNAs to the missing heritability in CYP3A4/5 functionality and the metabolism of atorvastatin

To evaluate the independent contribution of miRNAs to the missing heritability in CYP3A4/5 functionality and atorvastatin metabolism, the relationships among three levels of factors, namely (1) clinical characteristics, CYP3A4/5 genotypes, and miRNAs, (2) CYP3A4 and CYP3A5 mRNAs, and (3) CYP3A activity, as well as their individual impacts on atorvastatin metabolism, were assessed in 55 human liver tissues. MiR-27b, miR-206, and CYP3A4 mRNA respectively accounted for 20.0%, 5.8%, and 9.5% of the interindividual variations in CYP3A activity. MiR-142 was an independent contributor to the expressions of CYP3A4 mRNA (partial R(2) = 0.12, P = 0.002) and CYP3A5 mRNA (partial R(2) = 0.09, P = 0.005) but not CYP3A activity or atorvastatin metabolism. CYP3A activity was a unique independent predictor of variability of atorvastatin metabolism, explaining the majority of the variance in reduction of atorvastatin (60.0%) and formation of ortho-hydroxy atorvastatin (78.8%) and para-hydroxy atorvastatin (83.9%). MiR-27b and miR-206 were found to repress CYP3A4 gene expression and CYP3A activity by directly binding to CYP3A4 3'-UTR, while miR-142 was found to indirectly repress CYP3A activity. Our study indicates that miRNAs play significant roles in bridging the gap between epigenetic effects and missing heritability in CYP3A functionality.

Multi-Organ toxicity demonstration in a functional human in vitro system composed of four organs

We report on a functional human model to evaluate multi-organ toxicity in a 4-organ system under continuous flow conditions in a serum-free defined medium utilizing a pumpless platform for 14 days. Computer simulations of the platform established flow rates and resultant shear stress within accepted ranges. Viability of the system was demonstrated for 14 days as well as functional activity of cardiac, muscle, neuronal and liver modules. The pharmacological relevance of the integrated modules were evaluated for their response at 7 days to 5 drugs with known side effects after a 48 hour drug treatment regime. The results of all drug treatments were in general agreement with published toxicity results from human and animal data. The presented phenotypic culture model exhibits a multi-organ toxicity response, representing the next generation of in vitro systems, and constitutes a step towards an in vitro "human-on-a-chip" assay for systemic toxicity screening.

Time for a change: addressing R&D and commercialization challenges for antibacterials

The antibacterial therapeutic area has been described as the perfect storm. Resistance is increasing to the point that our hospitals encounter patients infected with untreatable pathogens, the overall industry pipeline is described as dry and most multinational pharmaceutical companies have withdrawn from the area. Major contributing factors to the declining antibacterial industry pipeline include scientific challenges, clinical/regulatory hurdles and low return on investment. This paper examines these challenges and proposes approaches to address them. There is a need for a broader scientific agenda to explore new approaches to discover and develop antibacterial agents. Additionally, ideas of how industry and academia could be better integrated will be presented. While promising progress in the regulatory environment has been made, more streamlined regulatory paths are still required and the solutions will lie in global harmonization and clearly defined guidance. Creating the right incentives for antibacterial research and development is critical and a new commercial model for antibacterial agents will be proposed. One key solution to help resolve both the problem of antimicrobial resistance (AMR) and lack of new drug development are rapid, cost-effective, accurate point of care diagnostics that will transform antibacterial prescribing and enable more cost-effective and efficient antibacterial clinical trials. The challenges of AMR are too great for any one group to resolve and success will require leadership and partnerships among academia, industry and governments globally.

Atorvastatin Reduces the Survival of Candida albicans-Infected BALB/c Mice

Several antimicrobial and immunosuppressive effects have been attributed to the statins class of antihyperlipidemia drugs. Several studies have also indicated clinical benefits for the use of statins during the management of infections and sepsis. To assess whether the immunosuppressive effects of statins outweigh their antimicrobial effects during a fungal infection BALB/c mice were administered Candida albicans via intraperitoneal injection. These mice received either a co-injection of atorvastatin along with the infection, were treated with one injection of atorvastatin per day for 5 days prior to infection, or were infected and then treated with one injection of atorvastatin for 5 days afterward. Groups that received C. albicans without being treated with atorvastatin were included as controls along with a group that only received phosphate-buffered saline. Mouse survival was then monitored; additionally, serum IFN-γ and IL-4 levels were determined by enzyme linked immunosorbent assay to assess pro-inflammatory and pro-humoral responses, respectively. Atorvastatin administration was capable of altering mouse survival rate with the lowest rate (11.1%) being observed in the group treated for 5 days prior to infection with atorvastatin compared to mice infected but not treated with atorvastatin (44.4%). IFN-γ and IL-4 levels were depressed in all C. albicans-infected groups treated with atorvastatin. The possibility that statin administration may suppress or modulate particular components of the immune system during an infection in man should be further explored in large randomized controlled trials.

Elucidation of novel 13-series resolvins that increase with atorvastatin and clear infections

Endogenous mechanisms leading to host protection and resolution of infections without immunosuppression are of wide interest^1,2. Here we elucidated the structures of four new host-protective molecules produced in neutrophil-endothelial co-cultures, and present in human and mouse tissues after sterile inflammation or infection. These bioactive molecules contained conjugated triene and diene double bonds with each carrying a 13-carbon position alcohol and were derived from n-3 docosapentaenoic acid (DPA, C22:5). These compounds, termed 13-series resolvins (RvT), demonstrated potent protective actions increasing mice survival during Escherichia coli infections. RvT also regulated human and mouse phagocyte responses stimulating bacterial phagocytosis and regulating inflammasome components. Their biosynthesis during neutrophil-endothelial cell interactions was initiated by endothelial cyclooxygenase-2 (COX-2) and increased by atorvastatin via S-nitrosylation of COX-2. The actions of atorvastatin and RvT were additive in E. coli infections in mice where they accelerated resolution of inflammation and increased survival >60%. These results document novel host protective molecules in bacterial infections, namely 13-series resolvins, derived from n-3 DPA via transcellular biosynthesis and increased by atorvastatin. These novel molecules regulate key innate protective responses in the resolution of infectious-inflammation.

Stability and removal of atorvastatin, rosuvastatin and simvastatin from wastewater

Atorvastatin (ATO), rosuvastatin (RST) and simvastatin (SIM) are commonly used drugs that belong to the statin family (lowering human blood cholesterol levels) and have been detected as contaminants in natural waters. Stability and removal of ATO, RST and SIM from spiked wastewater produced at the Al-Quds University campus were investigated. All three statins were found to undergo degradation in wastewater (activated sludge). The degradation reactions of the three drugs in wastewater at room temperature follow first-order kinetics with rate constants of 2.2 × 10⁻⁷ s⁻¹ (ATO), 1.8 × 10⁻⁷ s⁻¹ (RST) and 1.8 × 10⁻⁶ s⁻¹ (SIM), which are larger than those obtained in pure water under the same conditions, 1.9 × 10⁻⁸ s⁻¹ (ATO), 2.2 × 10⁻⁸ s⁻¹ (RST) and 6.2 × 10⁻⁷ s⁻¹ (SIM). Degradation products were identified by LC-MS and LC/MS/MS. The overall performance of the wastewater treatment plant (WWTP) installed in the Al-Quds University campus towards the removal of these drugs was assessed showing that more than 90% of spiked ATO, RST and SIM were removed. In order to evaluate the efficiency of alternative removal methods to replace ultra-filtration membranes, adsorption isotherms for the three statins were investigated using both activated carbon and clay-micelle complex as adsorbents. The batch adsorption isotherms for the three statins were found to fit the Langmuir equation, with a larger number of adsorption sites and binding affinity for micelle-clay composite compared with activated carbon and filtration experiments of the three statins and their corresponding metabolites demonstrated a more efficient removal by micelle-clay filters.

Lipid-lowering efficacy of atorvastatin

BACKGROUND

This represents the first update of this review, which was published in 2012. Atorvastatin is one of the most widely prescribed drugs and the most widely prescribed statin in the world. It is therefore important to know the dose-related magnitude of effect of atorvastatin on blood lipids.

OBJECTIVES

Primary objective To quantify the effects of various doses of atorvastatin on serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and triglycerides in individuals with and without evidence of cardiovascular disease. The primary focus of this review was determination of the mean per cent change from baseline of LDL-cholesterol. Secondary objectives • To quantify the variability of effects of various doses of atorvastatin.• To quantify withdrawals due to adverse effects (WDAEs) in placebo-controlled randomised controlled trials (RCTs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 11, 2013), MEDLINE (1966 to December Week 2 2013), EMBASE (1980 to December Week 2 2013), Web of Science (1899 to December Week 2 2013) and BIOSIS Previews (1969 to December Week 2 2013). We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled and uncontrolled before-and-after trials evaluating the dose response of different fixed doses of atorvastatin on blood lipids over a duration of three to 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility criteria for studies to be included and extracted data. We collected information on withdrawals due to adverse effects from placebo-controlled trials.

MAIN RESULTS

In this update, we found an additional 42 trials and added them to the original 254 studies. The update consists of 296 trials that evaluated dose-related efficacy of atorvastatin in 38,817 participants. Included are 242 before-and-after trials and 54 placebo-controlled RCTs. Log dose-response data from both trial designs revealed linear dose-related effects on blood total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides. The Summary of findings table 1 documents the effect of atorvastatin on LDL-cholesterol over the dose range of 10 to 80 mg/d, which is the range for which this systematic review acquired the greatest quantity of data. Over this range, blood LDL-cholesterol is decreased by 37.1% to 51.7% (Summary of findings table 1). The slope of dose-related effects on cholesterol and LDL-cholesterol was similar for atorvastatin and rosuvastatin, but rosuvastatin is about three-fold more potent. Subgroup analyses suggested that the atorvastatin effect was greater in females than in males and was greater in non-familial than in familial hypercholesterolaemia. Risk of bias for the outcome of withdrawals due to adverse effects (WDAEs) was high, but the mostly unclear risk of bias was judged unlikely to affect lipid measurements. Withdrawals due to adverse effects were not statistically significantly different between atorvastatin and placebo groups in these short-term trials (risk ratio 0.98, 95% confidence interval 0.68 to 1.40).

AUTHORS' CONCLUSIONS

This update resulted in no change to the main conclusions of the review but significantly increases the strength of the evidence. Studies show that atorvastatin decreases blood total cholesterol and LDL-cholesterol in a linear dose-related manner over the commonly prescribed dose range. New findings include that atorvastatin is more than three-fold less potent than rosuvastatin, and that the cholesterol-lowering effects of atorvastatin are greater in females than in males and greater in non-familial than in familial hypercholesterolaemia. This review update does not provide a good estimate of the incidence of harms associated with atorvastatin because included trials were of short duration and adverse effects were not reported in 37% of placebo-controlled trials.

Uremic toxins enhance statin-induced cytotoxicity in differentiated human rhabdomyosarcoma cells

The risk of myopathy and rhabdomyolysis is considerably increased in statin users with end-stage renal failure (ESRF). Uremic toxins, which accumulate in patients with ESRF, exert cytotoxic effects that are mediated by various mechanisms. Therefore, accumulation of uremic toxins might increase statin-induced cytotoxicity. The purpose of this study was to determine the effect of four uremic toxins-hippuric acid, 3-carboxy-4-methyl-5-propyl-2-furanpropionate, indole-3-acetic acid, and 3-indoxyl sulfate-on statin-induced myopathy. Differentiated rhabdomyosarcoma cells were pre-treated with the uremic toxins for seven days, and then the cells were treated with pravastatin or simvastatin. Cell viability and apoptosis were assessed by viability assays and flow cytometry. Pre-treatment with uremic toxins increased statin- but not cisplatin-induced cytotoxicity (p < 0.05 vs. untreated). In addition, the pre-treatment increased statin-induced apoptosis, which is one of the cytotoxic factors (p < 0.05 vs. untreated). However, mevalonate, farnesol, and geranylgeraniol reversed the effects of uremic toxins and lowered statin-induced cytotoxicity (p < 0.05 vs. untreated). These results demonstrate that uremic toxins enhance statin-induced apoptosis and cytotoxicity. The mechanism underlying this effect might be associated with small G-protein geranylgeranylation. In conclusion, the increased severity of statin-induced rhabdomyolysis in patients with ESRF is likely due to the accumulation of uremic toxins.

HPLC-DAD Method for the Pharmacokinetic Interaction Study of Atorvastatin with Pioglitazone and Cholestyramine in Wistar Rats

Carotid intima-media thickness is used as a surrogate marker for cardiovascular complications in diabetes mellitus. The combination of atorvastatin and pioglitazone was found to be effective in reducing the thickness of the carotid intima-media layer. The method of RP-HPLC coupled with a diode array detector (DAD) was developed for the pharmacokinetic interaction study of atorvastatin with pioglitazone and cholestyramine, respectively, in Wistar rats. Atorvastatin (ATR) and pioglitazone (PIO) were resolved on a C₁₈ column with a mobile phase composed of 48% methanol, 19% acetonitrile, and 33% 10 mM ammonium formate (v/v/v; pH 3.5±0.3, by formic acid) and a 260 nm detection wavelength on the diode array detector. The method was validated according to international standards with good reproducibility and linear response; mean (r) 0.9987 and 0.9972 to ATR and PIO, respectively. The coefficients of variation of intra- and interassay precision ranged between 4.95–8.12 and 7.29–9.67, respectively. Pharmacokinetic parameters were determined in rats following an oral administration of atorvastatin in the presence and absence of pioglitazone and also with cholestyramine. Compared with the control given atorvastatin alone, the C_max and AUC of atorvastatin were merely unchanged in rats with the co-administration of pioglitazone, while they decreased by nearly 21 and 15%, respectively, with the concurrent use of cholestyramine. There were no significant changes in T_max and the plasma half-life (T_1/2) of atorvastatin in both cases. The performed experiment demonstrated that the presented method was suitable for the estimation and pharmacokinetic interaction study of atorvastatin with pioglitazone and cholestyramine in Wistar rat plasma.

Cytochrome P450 Enzyme Metabolites in Lead Discovery and Development

The cytochrome P450 (CYP) enzymes are a versatile superfamily of heme-containing monooxygenases, perhaps best known for their role in the oxidation of xenobiotic compounds. However, due to their unique oxidative chemistry, CYPs are also important in natural product drug discovery and in the generation of active metabolites with unique therapeutic properties. New tools for the analysis and production of CYP metabolites, including microscale analytical technologies and combinatorial biosynthesis, are providing medicinal chemists with the opportunity to use CYPs as a novel platform for lead discovery and development. In this review, we will highlight some of the recent examples of drug leads identified from CYP metabolites and the exciting possibilities of using CYPs as catalysts for future drug discovery.

Management of statin intolerance

Statins are the revolutionary drugs in the cardiovascular pharmacotherapy. But they also possess several adverse effects like myopathy with elevation of hepatic transaminases (>3 times the upper limit of normal) or creatine kinase (>10 times the upper limit of normal) and some rare side-effects, including peripheral neuropathy, memory loss, sleep disturbances, and erectile dysfunction. Due to these adverse effects, patients abruptly withdrew statins without consulting physicians. This abrupt discontinuation of statins is termed as statin intolerance. Statin-induced myopathy constitutes two third of all side-effects from statins and is the primary reason for statin intolerance. Though statin intolerance has considerably impacted cardiovascular outcomes in the high-risk patients, it has been well effectively managed by prescribing statins either as alternate-day or once weekly dosage regimen, as combination therapy with a non-statin therapy or and by dietary intervention. The present article reviews the causes, clinical implications of statin withdrawal and management of statin intolerance.

HMG CoA reductase inhibitors (statins) for dialysis patients

BACKGROUND

People with advanced kidney disease treated with dialysis experience mortality rates from cardiovascular disease that are substantially higher than for the general population. Studies that have assessed the benefits of statins (HMG CoA reductase inhibitors) report conflicting conclusions for people on dialysis and existing meta-analyses have not had sufficient power to determine whether the effects of statins vary with severity of kidney disease. Recently, additional data for the effects of statins in dialysis patients have become available. This is an update of a review first published in 2004 and last updated in 2009.

OBJECTIVES

To assess the benefits and harms of statin use in adults who require dialysis (haemodialysis or peritoneal dialysis).

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 29 February 2012 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care or other statins on mortality, cardiovascular events and treatment-related toxicity in adults treated with dialysis were sought for inclusion.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed study risk of bias. Treatment effects were summarised using a random-effects model and subgroup analyses were conducted to explore sources of heterogeneity. Treatment effects were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes together with 95% confidence intervals (CI).

MAIN RESULTS

The risk of bias was high in many of the included studies. Random sequence generation and allocation concealment was reported in three (12%) and four studies (16%), respectively. Participants and personnel were blinded in 13 studies (52%), and outcome assessors were blinded in five studies (20%). Complete outcome reporting occurred in nine studies (36%). Adverse events were only reported in nine studies (36%); 11 studies (44%) reported industry funding.We included 25 studies (8289 participants) in this latest update; 23 studies (24 comparisons, 8166 participants) compared statins with placebo or no treatment, and two studies (123 participants) compared statins directly with one or more other statins. Statins had little or no effect on major cardiovascular events (4 studies, 7084 participants: RR 0.95, 95% CI 0.88 to 1.03), all-cause mortality (13 studies, 4705 participants: RR 0.96, 95% CI 0.90 to 1.02), cardiovascular mortality (13 studies, 4627 participants: RR 0.94, 95% CI 0.84 to 1.06) and myocardial infarction (3 studies, 4047 participants: RR 0.87, 95% CI 0.71 to 1.07); and uncertain effects on stroke (2 studies, 4018 participants: RR 1.29, 95% CI 0.96 to 1.72).Risks of adverse events from statin therapy were uncertain; these included effects on elevated creatine kinase (5 studies, 3067 participants: RR 1.25, 95% CI 0.55 to 2.83) or liver function enzymes (4 studies, 3044 participants; RR 1.09, 95% CI 0.41 to 1.25), withdrawal due to adverse events (9 studies, 1832 participants: RR 1.04, 95% CI 0.87 to 1.25) or cancer (2 studies, 4012 participants: RR 0.90, 95% CI 0.72 to 1.11). Statins reduced total serum cholesterol (14 studies, 1803 participants; MD -44.86 mg/dL, 95% CI -55.19 to -34.53) and low-density lipoprotein cholesterol (12 studies, 1747 participants: MD -39.99 mg/dL, 95% CI -52.46 to -27.52) levels. Data comparing statin therapy directly with another statin were sparse.

AUTHORS' CONCLUSIONS

Statins have little or no beneficial effects on mortality or cardiovascular events and uncertain adverse effects in adults treated with dialysis despite clinically relevant reductions in serum cholesterol levels.

Effects of decreased vitamin D and accumulated uremic toxin on human CYP3A4 activity in patients with end-stage renal disease

In patients with end-stage renal disease, not only renal clearance but also hepatic clearance is known to be impaired. For instance, the concentration of erythromycin, a substrate of cytochrome P450 3A4 (CYP3A4), has been reported to be elevated in patients with end-stage renal disease. The purpose of this study is to elucidate the reason for the decrease in hepatic clearance in patients with end-stage renal disease. Deproteinized pooled sera were used to assess the effects of low-molecular-weight uremic toxins on CYP3A4 activity in human liver microsomes and human LS180 cells. Four uremic toxins (3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid, hippuric acid, indole-3-acetic acid, and 3-indoxyl sulfate) present at high concentrations in uremic serum were also studied. Simultaneous treatment of uremic serum (less than 10%) or uremic toxins did not affect testosterone 6β-hydroxylation in human liver microsomes. On the other hand, pretreatment of each serum activates CYP3A4 in LS180 cells, and the increased CYP3A4 activity in uremic serum-treated cells was smaller than normal serum-treated cells. In addition, CYP3A4 and CYP24A1 mRNA levels also increased in LS180 cells exposed to normal serum, and this effect was reduced in uremic serum-treated cells and in cells exposed to uremic serum added to normal serum. Furthermore, addition of 1,25-dihydroxyvitamin D to uremic serum partially restored the serum effect on CYP3A4 expression. The present study suggests that the decrease of 1,25-dihydroxyvitamin D and the accumulation of uremic toxins contributed to the decreased hepatic clearance of CYP3A4 substrates in patients with end-stage renal disease.