Rhabdomyolysis reports show interaction between simvastatin and CYP3A4 inhibitors

Endoscopic diagnosis and management of nonvariceal upper gastrointestinal hemorrhage (NVUGIH): European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2021

1: ESGE recommends in patients with acute upper gastrointestinal hemorrhage (UGIH) the use of the Glasgow-Blatchford Score (GBS) for pre-endoscopy risk stratification. Patients with GBS ≤ 1 are at very low risk of rebleeding, mortality within 30 days, or needing hospital-based intervention and can be safely managed as outpatients with outpatient endoscopy.Strong recommendation, moderate quality evidence. 2: ESGE recommends that in patients with acute UGIH who are taking low-dose aspirin as monotherapy for secondary cardiovascular prophylaxis, aspirin should not be interrupted. If for any reason it is interrupted, aspirin should be re-started as soon as possible, preferably within 3-5 days.Strong recommendation, moderate quality evidence. 3: ESGE recommends that following hemodynamic resuscitation, early (≤ 24 hours) upper gastrointestinal (GI) endoscopy should be performed. Strong recommendation, high quality evidence. 4: ESGE does not recommend urgent (≤ 12 hours) upper GI endoscopy since as compared to early endoscopy, patient outcomes are not improved. Strong recommendation, high quality evidence. 5: ESGE recommends for patients with actively bleeding ulcers (FIa, FIb), combination therapy using epinephrine injection plus a second hemostasis modality (contact thermal or mechanical therapy). Strong recommendation, high quality evidence. 6: ESGE recommends for patients with an ulcer with a nonbleeding visible vessel (FIIa), contact or noncontact thermal therapy, mechanical therapy, or injection of a sclerosing agent, each as monotherapy or in combination with epinephrine injection. Strong recommendation, high quality evidence. 7 : ESGE suggests that in patients with persistent bleeding refractory to standard hemostasis modalities, the use of a topical hemostatic spray/powder or cap-mounted clip should be considered. Weak recommendation, low quality evidence. 8: ESGE recommends that for patients with clinical evidence of recurrent peptic ulcer hemorrhage, use of a cap-mounted clip should be considered. In the case of failure of this second attempt at endoscopic hemostasis, transcatheter angiographic embolization (TAE) should be considered. Surgery is indicated when TAE is not locally available or after failed TAE. Strong recommendation, moderate quality evidence. 9: ESGE recommends high dose proton pump inhibitor (PPI) therapy for patients who receive endoscopic hemostasis and for patients with FIIb ulcer stigmata (adherent clot) not treated endoscopically. (A): PPI therapy should be administered as an intravenous bolus followed by continuous infusion (e. g., 80 mg then 8 mg/hour) for 72 hours post endoscopy. (B): High dose PPI therapies given as intravenous bolus dosing (twice-daily) or in oral formulation (twice-daily) can be considered as alternative regimens.Strong recommendation, high quality evidence. 10: ESGE recommends that in patients who require ongoing anticoagulation therapy following acute NVUGIH (e. g., peptic ulcer hemorrhage), anticoagulation should be resumed as soon as the bleeding has been controlled, preferably within or soon after 7 days of the bleeding event, based on thromboembolic risk. The rapid onset of action of direct oral anticoagulants (DOACS), as compared to vitamin K antagonists (VKAs), must be considered in this context.Strong recommendation, low quality evidence.

Treatment patterns of lipid-lowering therapies and possible statin intolerance among statin users with clinical atherosclerotic cardiovascular disease (ASCVD) or diabetes mellitus (DM) in Taiwan

OBJECTIVES

To assess treatment patterns of statin and/or ezetimibe and possible statin intolerance among patients initiating statin or statin plus ezetimibe and with clinical atherosclerotic cardiovascular disease (ASCVD) or diabetes mellitus (DM) in Taiwan.

METHODS

A retrospective cohort study using Taiwan's 2005 to 2013 National Health Insurance Research Database (NHIRD) was conducted. Patients with history of clinical ASCVD or DM (without previous clinical ASCVD) and initiating statin or statin plus ezetimibe therapy during 2006 to 2012 were identified. The treatment initiation date was defined as index date. Treatment patterns (including discontinuation, reinitiation, subtraction, switching, and augmentation), adherence (medication possession ratio [MPR]), persistence (gap no greater than 60 d) of statin and/or ezetimibe, and possible statin intolerance during 12-month follow-up from the index date were examined.

RESULTS

Among patients initiating statin or statin plus ezetimibe, 11 092 patients with history of clinical ASCVD and 31 100 patients with DM but without clinical ASCVD were analysed. The discontinuation, reinitiation, and switching rates among patients with clinical ASCVD were 54.0%, 11.3%, and 25.7% during 12-month follow-up period, respectively. Among patients with DM, the rates were 57.5%, 14.2%, and 28.5%. The MPRs of statin among clinical ASCVD and DM cohorts were 0.62 and 0.60, respectively. As for ezetimibe, the MPRs were 0.56 and 0.59. Persistence to statin treatment was 46.1% among ASCVD patients and 42.6% among DM patients. Among the ASCVD and DM cohorts, possible statin intolerance was observed among 19.9% and 21.4% of patients, respectively.

CONCLUSIONS

Large number of patients with either ASCVD or DM discontinued lipid-lowering therapies with suboptimal adherence and persistence among Taiwanese population. There is a large unmet medical need to provide safe and more effective therapies, which can be used in combination with statins or alone, to reduce the risk of CV events and improve outcomes in high-risk patients.

The clinical significance of statins-macrolides interaction: comprehensive review of in vivo studies, case reports, and population studies

The objectives of this article were to review the mechanism and clinical significance of statins-macrolides interaction, determine which combination has the highest risk for the interaction, and identify key patients' risk factors for the interaction in relation to the development of muscle toxicity. A literature review was conducted in PubMed and Embase (1946 to December 2018) using combined terms: statins - as group and individual agents, macrolides - as group and individual agents, drug interaction, muscle toxicity, rhabdomyolysis, CYP3A4 inhibitors, and OAT1B inhibitors, with forward and backward citation tracking. Relevant English language in vivo studies in healthy volunteers, case reports, and population studies were included. The interaction between statins and macrolides depends on the type of statin and macrolide used. The mechanism of the interaction is due to macrolides' inhibition of CYP3A4 isoenzyme and OAT1B transporter causing increased exposure to statins. The correlation of this increased statin's exposure to the development of muscle toxicity could not be established, unless the patient had other risk factors such as advanced age, cardiovascular diseases, renal impairment, diabetes, and the concomitant use of other CYP3A4 inhibitors. Simvastatin, lovastatin, and to lesser extent atorvastatin are the statins most affected by this interaction. Rosuvastatin, fluvastatin, and pravastatin are not significantly affected by this interaction. Telithromycin, clarithromycin, and erythromycin are the most "offending" macrolides, while azithromycin appears to be safe to use with statins. This review presented a clear description of the clinical significance of this interaction in real practice. Also, it provided health care professionals with clear suggestions and recommendations on how to overcome this interaction. In conclusion, understanding the different characteristics of each statin and macrolide, as well as key patients' risk factors, will enable health care providers to utilize both groups effectively without compromising patient safety.

Trends and variations in outpatient coprescribing of simvastatin or atorvastatin with potentially interacting drugs in Thailand

Background:

The aim of this study was to assess trends and variations in coprescribing of simvastatin or atorvastatin with interacting drugs in Thailand.

Methods:

Outpatient prescriptions between 2013 and 2015 in 26 tertiary care hospitals were analyzed for statin coprescribing. The proportion of patients exposed to coprescribing was estimated for semi-annual changes, using a time-series analysis and for hospital variations, using an interquartile range (IQR).

Results:

The coprescribing of simvastatin with all contraindicated drugs in 10 university and 16 general hospitals, respectively, was 3.6 and 3.1% in 2013, then decreased to 3.2 and 2.6% in 2014 and to 2.6 and 2.0% in 2015. The drug most frequently coprescribed with simvastatin, on a decreasing trend (by 0.19 percentage points) was gemfibrozil (in 2013, 2014 and 2015, respectively; 2.9, 2.3 and 2.0% in university hospitals, and 2.5, 2.0 and 1.6% in general hospitals). A similar trend was found in atorvastatin-gemfibrozil coprescribing. Patients coprescribed simvastatin with the rest of the contraindicated drugs were relatively stable at 0.6–0.8%. No protease inhibitors were coprescribed with simvastatin and atorvastatin. The IQR of simvastatin coprescribing in the university hospitals was smaller than that in the general hospitals and decreased over time.

Conclusions:

Coprescriptions potentially leading to drug interactions with simvastatin in Thailand were observed although the contraindicated drugs were acknowledged. Mutual awareness among health professionals and the implementation of electronic prescribing should be strengthened as zero drug interaction was possible as in the case of protease inhibitors in the present study.

Onset timing of statin-induced musculoskeletal adverse events and concomitant drug-associated shift in onset timing of MAEs

To evaluate the onset timing of musculoskeletal adverse events (MAEs) that develop during statin monotherapy and to determine whether concomitant drugs used concurrently with statin therapy shifts the onset timing of MAEs. Cases in which statins (atorvastatin, rosuvastatin, simvastatin, lovastatin, fluvastatin, pitavastatin, and pravastatin) were prescribed were extracted from the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) Data Files. The onset timing of MAEs during statin monotherapy was evaluated by determining the difference between statin start date and MAE onset date. The use of concomitant drugs with statin therapy was included in the analysis. Statins used in combination with concomitant drugs were compared with statin monotherapy to determine if the use of concomitant drugs shifted the onset timing of MAEs. The onset of MAEs was significantly faster with atorvastatin and rosuvastatin than with simvastatin. A difference in onset timing was not detected with other statins because the number of cases was too small for analysis. When evaluating concomitant drug use, the concomitant drugs that shifted the onset timing of MAEs could not be detected. Statins with strong low-density lipoprotein cholesterol-lowering effects (atorvastatin and rosuvastatin) contributed not only to a high risk of MAE onset, but also to a shorter time-to-onset. No concomitant drug significantly shifted the onset timing of MAEs when used concurrently with statins.

Diplomats' Mystery Illness and Pulsed Radiofrequency/Microwave Radiation

Importance: A mystery illness striking U.S. and Canadian diplomats to Cuba (and now China) "has confounded the FBI, the State Department and US intelligence agencies" (Lederman, Weissenstein, & Lee, 2017). Sonic explanations for the so-called health attacks have long dominated media reports, propelled by peculiar sounds heard and auditory symptoms experienced. Sonic mediation was justly rejected by experts. We assessed whether pulsed radiofrequency/microwave radiation (RF/MW) exposure can accommodate reported facts in diplomats, including unusual ones. Observations: (1) Noises: Many diplomats heard chirping, ringing or grinding noises at night during episodes reportedly triggering health problems. Some reported that noises were localized with laser-like precision or said the sounds seemed to follow them (within the territory in which they were perceived). Pulsed RF/MW engenders just these apparent "sounds" via the Frey effect. Perceived "sounds" differ by head dimensions and pulse characteristics and can be perceived as located behind in or above the head. Ability to hear the "sounds" depends on high-frequency hearing and low ambient noise. (2) Signs/symptoms: Hearing loss and tinnitus are prominent in affected diplomats and in RF/MW-affected individuals. Each of the protean symptoms that diplomats report also affect persons reporting symptoms from RF/MW: sleep problems, headaches, and cognitive problems dominate in both groups. Sensations of pressure or vibration figure in each. Both encompass vision, balance, and speech problems and nosebleeds. Brain injury and brain swelling are reported in both. (3) Mechanisms: Oxidative stress provides a documented mechanism of RF/MW injury compatible with reported signs and symptoms; sequelae of endothelial dysfunction (yielding blood flow compromise), membrane damage, blood-brain barrier disruption, mitochondrial injury, apoptosis, and autoimmune triggering afford downstream mechanisms, of varying persistence, that merit investigation. (4) Of note, microwaving of the U.S. embassy in Moscow is historically documented. Conclusions and relevance: Reported facts appear consistent with pulsed RF/MW as the source of injury in affected diplomats. Nondiplomats citing symptoms from RF/MW, often with an inciting pulsed-RF/MW exposure, report compatible health conditions. Under the RF/MW hypothesis, lessons learned for diplomats and for RF/MW-affected civilians may each aid the other.

Treatment Patterns, Statin Intolerance, and Subsequent Cardiovascular Events Among Japanese Patients With High Cardiovascular Risk Initiating Statin Therapy

BACKGROUND

This study examined treatment patterns, possible statin intolerance, and incidence of cardiovascular events (CVEs) in 2 cohorts of patients with high cardiovascular risk (i.e., patients with atherosclerotic cardiovascular disease [ASCVD] and patients with diabetes mellitus).

METHODS AND RESULTS

A retrospective cohort study examined adults initiating either a statin or ezetimibe from 1 January 2006 to 31 May 2014 in the Japan Medical Data Center database. The first observed statin or ezetimibe prescription defined the index date. Patients had ≥12 months of pre- and post-index date plan enrollment. Two high-risk cohorts, the ASCVD cohort and diabetes cohort, were created based on diagnoses observed during the 12 months' pre-index date. Treatment patterns, possible statin intolerance, and incidence of CVEs were reported. In the ASCVD cohort (n=5,302), 32.9% discontinued therapy, 7.7% switched to a non-index statin or non-statin lipid-lowering therapy, and 11.2% augmented index therapy in the 12 months' post-index date; only 0.3% were using high-intensity statins and 10% had possible statin intolerance. Also, 8.1% had any new CVE during the follow-up period. Treatment patterns and incidence of CVEs among the diabetes cohort were similar to those of the ASCVD cohort.

CONCLUSIONS

High cardiovascular risk Japanese patients had frequent treatment modifications, although use of high-intensity statin doses was rare. These patterns may indicate that alternative therapies for lipid lowering are needed.

Individual and Combined Associations of Genetic Variants in CYP3A4, CYP3A5, and SLCO1B1 With Simvastatin and Simvastatin Acid Plasma Concentrations

Our objective was to evaluate the associations of genetic variants affecting simvastatin (SV) and simvastatin acid (SVA) metabolism [the gene encoding cytochrome P450, family 3, subfamily A, polypeptide 4 (CYP3A4)*22 and the gene encoding cytochrome P450, family 3, subfamily A, polypeptide 5 (CYP3A5)*3] and transport [the gene encoding solute carrier organic anion transporter family member 1B1 (SLCO1B1) T521C] with 12-hour plasma SV and SVA concentrations. The variants were genotyped, and the concentrations were quantified by high performance liquid chromatography-tandem mass spectrometry in 646 participants of the Cholesterol and Pharmacogenetics clinical trial of 40 mg/d SV for 6 weeks. The genetic variants were tested for association with 12-hour plasma SV, SVA, or the SVA/SV ratio using general linear models. CYP3A5*3 was not significantly associated with 12-hour plasma SV or SVA concentration. CYP3A4*1/*22 participants had 58% higher 12-hour plasma SV concentration compared with CYP3A4*1/*1 participants (P = 0.006). SLCO1B1 521T/C and 521C/C participants had 71% (P < 0.001) and 248% (P < 0.001) higher 12-hour plasma SVA compared with SLCO1B1 521T/T participants, respectively. CYP3A4 and SLCO1B1 genotypes combined categorized participants into low (<1), intermediate (≈1), and high (>1) SVA/SV ratio groups (P = 0.001). In conclusion, CYP3A4*22 and SLCO1B1 521C were significantly associated with increased 12-hour plasma SV and SVA concentrations, respectively. CYP3A5*3 was not significantly associated with 12-hour plasma SV or SVA concentrations. The combination of CYP3A4*22 and SLCO1B1 521C was significantly associated with SVA/SV ratio, which may translate into different clinical SV risk/benefit profiles.

Inhibitory and inductive effects of Phikud Navakot extract on human cytochrome P450

Effects of the hydroethanolic extract of Phikud Navakot (PN), a Thai traditional remedy, on human cytochrome P450s (CYPs) were investigated in vitro. Selective substrates of CYPs were used to investigate the effects and kinetics of PN on CYP inhibition using human liver microsomes. Primary human hepatocytes were used to assess the inductive effects of PN on CYP enzyme activities and protein expressions. The results showed that PN inhibited the activities of CYP1A2, CYP2C9, CYP2D6, and CYP3A4 with half maximal inhibitory concentration (IC50) values of 13, 62, 67, and 88 μg/mL, respectively. Meanwhile, it had no effect on the activities of CYP2C19 and CYP2E1 (IC50 > 1 mg/mL). PN exhibited competitive inhibition of CYP1A2 (Ki = 34 μg/mL), mixed type inhibition of CYP2C9 and CYP2D6 (Ki = 80 and 12 μg/mL, respectively), and uncompetitive inhibition of CYP3A4 (Ki = 150 μg/mL). PN did not have an inductive effect on CYP1A2, CYP2C9, CYP2C19 and CYP3A4 in primary human hepatocytes, which is an advantageous characteristic of the extract. However the extract may cause herb-drug interactions via inhibition of CYP1A2, CYP2C9, CYP2D6 and CYP3A4, and precautions should be taken when PN is coadministered with drugs that are metabolized by these CYP enzymes.

A population-based analysis of the risk of drug interaction between clarithromycin and statins for hospitalisation or death

Background

Clarithromycin, known as a potent inhibitor of the cytochrome P450 isoenzyme CYP3A, may increase the plasma concentration of statins metabolized by this pathway; therefore, increase the risk of interaction with statins in reference to pharmacokinetic studies. This study aimed to characterize whether the concomitant use of a statin with clarithromycin is associated with serious outcomes among adult persons.

Methods

Health claims data of adult persons in the Regional Sickness Fund of Burgenland, Austria, who filled a prescription for clarithromycin between July 1, 2009 and June 30, 2012 were reviewed retrospectively. We assumed that the risk of hospitalisation increases acutely with the indication for taking an antibiotic, whereas statin use can be considered a chronic exposure with a low constant effect on hospitalisation. When defining the population as persons taking clarithromycin and the use of statins as the exposure we could achieve a comparable effect in both groups from the acute condition on hospitalisation. Therefore, we defined exposed patients as those who had overlapping treatment with a statin and unexposed controls as those who had filled a prescription for clarithromycin without concomitant statin therapy. Outcome was defined as a composite of hospital admission or death within 30 days after starting clarithromycin. We used generalised linear regression to model an association between outcome and exposure to statins.

Results

Among 28,484 prescriptions of clarithromycin, 2317 persons were co-exposed to statins. Co-administration of CYP3A4 metabolized statins and clarithromycin was associated with a 2.11 fold increased risk of death or hospitalisation (95 % confidence interval [CI]: 1.79–2.48). This effect was explained by age, evidence of cardiovascular disease, diabetes mellitus and utilization of other antibiotics (multivariable adjusted risk ratio: 1.02, 95 % CI: 0.85–1.22). The sensitivity analyses did not change the significance of effect.

Conclusions

The risk for hospitalisation or death in persons receiving clarithromycin increases with age and cardiovascular disease but is not causally associated with statin-clarithromycine co-administration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12944-015-0134-y) contains supplementary material, which is available to authorized users.

Co-medication of statins with contraindicated drugs

Background

The concomitant use of cytochrome P450 3A4 (CYP3A4) metabolized statins (simvastatin, lovastatin, and atorvastatin) with CYP3A4 inhibitors has been shown to increase the rate of adverse events.

Objective

This study was performed to describe the co-medication prevalence of CYP3A4-metabolized statins with contraindicated drugs.

Methods

The patients aged 40 or older receiving CYP3A4-metabolized statin prescriptions in 2009 were identified using the national patient sample from a Korea Health Insurance Review and Assessment Service database. Contraindicated co-medication was defined as prescription periods of statins and contraindicated drugs overlapping by at least one day. Co-medication patterns were classified into 3 categories as follows: co-medication in the same prescription, co-medication by the same medical institution, and co-medication by different medical institutions. The proportion of co-medication was analyzed by age, gender, co-morbidities, and the statin’s generic name.

Results

A total of 2,119,401 patients received CYP3A4-metabolized statins and 60,254 (2.84%) patients were co-medicated with contraindicated drugs. The proportion of co-medication was 4.6%, 2.2%, and 1.8% in simvastatin, lovastatin, and atorvastatin users, respectively. The most frequent combination was atorvastatin-itraconazole, followed by simvastatin-clarithromycin and simvastatin-itraconazole. Among the co-medicated patients, 85.3% were prescribed two drugs by different medical institutions.

Conclusion

The proportion of co-medication of statins with contraindicated drugs was relatively lower than that of previous studies; however, the co-medication occurring by different medical institutions was not managed appropriately. There is a need to develop an effective system and to conduct outcomes research confirming the association between co-medication and the risk of unfavorable clinical outcomes.

Rhabdomyolysis in association with simvastatin and dosage increment in clarithromycin

Clarithromycin is the most documented cytochrome P450 3A4 (CYP3A4) inhibitor to cause an adverse interaction with simvastatin. This particular case is of interest as rhabdomyolysis only occurred after an increase in the dose of clarithromycin. The patient developed raised cardiac biomarkers without any obvious cardiac issues, a phenomenon that has been linked to rhabdomyolysis previously. To date, there has been no reported effect of rhabdomyolysis on the structure and function of cardiac muscle. Clinicians need to be aware of prescribing concomitant medications that increase the risk of myopathy or inhibit the CYP3A4 enzyme. Our case suggests that troponin elevation could be associated with statin induced rhabdomyolysis, which may warrant further studies.

Pravastatin-induced rhabdomyolysis and purpura fulminans in a patient with chronic renal failure

INTRODUCTION

Rhabdomyolysis associated with the use of pravastatin has been demonstrated to be a rare but potentially life-threatening adverse effect of statins. Here, we report a rare case of rhabdomyolysis and purpura fulminans in a patient who had used pravastatin and developed chronic renal failure (CRF) necessitating the initiation of dialysis.

PRESENTATION OF CASE

We present the case of an 86-year-old man with chronic kidney disease (CKD) treated with dialysis who was admitted with back pain. He was prescribed and took pravastatin for almost 3 years to treat hyperlipidemia. He received hemodialysis therapy 7 times prior to presentation. Laboratory values included a serum creatine concentration of 6.6mg/dl and a creatinine phosphokinase (CPK) concentration of 2350IU/L. An abdominal computed tomography scan showed swollen muscles with reduced muscle density and air density in the multifidus muscle. Two days after admission, he had large, tender ecchymotic lesions and purpuric progressive skin necrosis over the back, abdomen, and upper and lower extremities. The patient died 6 days after the initial admission due to disseminated intravascular coagulation (DIC). Based on these findings and the clinical history, a diagnosis of pravastatin-induced rhabdomyolysis and purpura fulminans was made.

DISCUSSION

The long-term use of statin therapy and the initiation of dialysis therapy due to ESRD, followed by a rapid onset of rhabdomyolysis within 6 days, is indicative of an elevated statin concentration.

CONCLUSION

We report an extremely rare case of pravastatin-induced rhabdomyolysis and purpura fulminans with DIC in a patient with CRF.

The effect of simvastatin on inflammatory cytokines in community-acquired pneumonia: a randomised, double-blind, placebo-controlled trial

OBJECTIVES

It has been suggested that statins have an effect on the modulation of the cytokine cascade and on the outcome of patients with community-acquired pneumonia (CAP). The aim of this prospective, randomised, double-blind, placebo-controlled trial was to determine whether statin therapy given to hospitalised patients with CAP improves clinical outcomes and reduces the concentration of inflammatory cytokines.

SETTING

A tertiary teaching hospital in Barcelona, Spain.

PARTICIPANTS

Thirty-four patients were randomly assigned and included in an intention-to-treat analysis (19 to the simvastatin group and 15 to the placebo group).

INTERVENTION

Patients were randomly assigned to receive 20 mg of simvastatin or placebo administered in the first 24 h of hospital admission and once daily thereafter for 4 days.

OUTCOME

Primary end point was the time from hospital admission to clinical stability. The secondary end points were serum concentrations of inflammatory cytokines and partial pressure of arterial oxygen/fractional inspired oxygen (PaO2/FiO2) at 48 h after treatment administration.

RESULTS

The trial was stopped because enrolment was much slower than originally anticipated. The baseline characteristics of the patients and cytokine concentrations at the time of enrolment were similar in the two groups. No significant differences in the time from hospital admission to clinical stability were found between study groups (median 3 days, IQR 2-5 vs 3 days, IQR 2-5; p=0.47). No significant differences in PaO2/FiO2 (p=0.37), C reactive protein (p=0.23), tumour necrosis factor-α (p=0.58), interleukin 6 (IL-6; p=0.64), and IL-10 (p=0.61) levels at 48 h of hospitalisation were found between simvastatin and placebo groups. Similarly, transaminase and total creatine kinase levels were similar between study groups at 48 h of hospitalisation (p=0.19, 0.08 and 0.53, respectively).

CONCLUSIONS

Our results suggest that the use of simvastatin, 20 mg once daily for 4 days, since hospital admission did not reduce the time to clinical stability and the levels of inflammatory cytokines in hospitalised patients with CAP.

TRIAL REGISTRATION NUMBER

ISRCTN91327214.

Pharmacokinetic interactions between simvastatin and setipiprant, a CRTH2 antagonist

PURPOSE

Setipiprant, a selective oral CRTH2 antagonist, has been investigated for the treatment of allergic rhinitis and asthma. In vitro data showed that setipiprant has a weak induction potential on CYP3A4. An interaction at the hepatic level between setipiprant and CYP3A4 substrates was not expected even at the dosing regimen of 1,000 mg setipiprant b.i.d. due to the high plasma protein binding. However, at this dosing regimen, interactions at the gut level could not be excluded.

METHODS

In this single-center, open-label study, 40 mg of simvastatin was administered orally on Day 1, and then concomitantly with setipiprant on Day 10 following 9 days of setipiprant 1,000 mg b.i.d. to 22 healthy male subjects.

RESULTS

In the presence of setipiprant, the simvastatin concentration-time profile was similar to that of simvastatin alone. The concentrations of simvastatin were, however, slightly lower, resulting in a 9 % decrease in C max (geometric mean ratio (GMR) 0.91, 90 % confidence interval (CI) (0.73, 1.13)) and in a 16 % lower AUC0-∞ (GMR 0.84, 90 % CI (0.72, 0.99)). Exposure to simvastatin acid was similar when comparing simvastatin with or without setipiprant. The GMR and 90 % CI for AUC0-∞ were within the 0.8 to 1.25 limits, whereas those for C max were outside (GMR 2.73, 90 % CI (2.11, 3.53)). Moreover, the median t max of simvastatin acid occurred earlier (1.8 h) when combined compared to 3.0 h when administered alone.

CONCLUSIONS

As setipiprant has little impact on simvastatin pharmacokinetics, it does not modulate CYP3A4 in a clinically relevant manner.

Translational insight into statin-induced muscle toxicity: from cell culture to clinical studies

Statins are lipid-lowering drugs used widely to prevent and treat cardiovascular and coronary heart diseases. These drugs are among the most commonly prescribed medicines intended for long-term use. In general, statins are well tolerated. However, muscular adverse effects appear to be the most common obstacle that limits their use, resulting in poor patient compliance or even drug discontinuation. In addition, rare but potentially fatal cases of rhabdomyolysis have been reported with the use of these drugs, especially in the presence of certain risk factors. Previous reports have investigated statin-induced myotoxicity in vivo and in vitro using a number of cell lines, muscle tissues, and laboratory animals, in addition to randomized clinical trials, observational studies, and case reports. None of them have compared directly results from laboratory investigations with clinical observations of statin-related muscular adverse effects. To the best of our knowledge this is the first review article that combines laboratory investigation with clinical aspects of statin-induced myotoxicity. By reviewing published literature of in vivo, in vitro, and clinically relevant studies of statin myotoxicity, we aim to translate this important drug-related problem to establish a clear picture of proposed mechanisms that explain the risk factors and describe the diagnostic approaches currently used for evaluating the degree of muscle damage induced by these agents. This review provides baseline novel translational insight that can be used to enhance the safety profile, to minimize the chance of progression of these adverse effects to more severe and potentially fatal rhabdomyolysis, and to improve the overall patient compliance and adherence to long-term statin therapy.

Rhabdomyolysis in an elderly multitreated patient: multiple drug interactions after statin withdrawal

Rhabdomyolysis precipitated by multitherapy is most frequently described during statin treatment, due to impairment of statin clearance by drugs sharing cytochrome P450 biotransformation pathway. Modulation of membrane transporters for drug efflux, operated by substrates, can also affect drugs' tissue levels. We report rhabdomyolysis in an elderly patient, in multitreatment with different potentially myotoxic medications, taking place seven months after atorvastatin discontinuation. Affected by ischaemic heart disease, arterial hypertension and dementia-related behaviour disturbances, the patient was receiving angiotensin 2-receptor inhibitors, beta-blockers, vasodilators, diuretics, salycilates, allopurinol, proton pump inhibitors, antipsychotics and antidepressants. He had taken atorvastatin for 14 years, with constantly normal creatine-kinase plasma levels. Two months after addition of the antianginal drug ranolazine, creatine-kinase mildly increased and atorvastatin was withdrawn. Nonetheless, creatine-kinase progressively rose, with severe weakness and rhabdomyolysis developing seven months later. Muscle biopsy showed a necrotizing myopathy with no inflammation or autoimmune changes. After ranolazine withdrawal, creatine-kinase and myoglobin returned to normal levels and strength was restored. Several psychotropic and cardiovascular medications prescribed to the patient share either cytochrome P450 biotransformation and permeability-glycoprotein efflux transport. In the event of cardiovascular/neuropsychiatric polypharmacy in geriatric patients, the risk of muscle severe adverse effects from pharmacokinetic drug-drug interaction should be considered beyond the direct myotoxicity of statins.

Benefits & risks of statin therapy for primary prevention of cardiovascular disease in Asian Indians - a population with the highest risk of premature coronary artery disease & diabetes

Several reviews and meta-analyses have demonstrated the incontrovertible benefits of statin therapy in patients with cardiovascular disease (CVD). But the role for statins in primary prevention remained unclear. The updated 2013 Cochrane review has put to rest all lingering doubts about the overwhelming benefits of long-term statin therapy in primary prevention by conclusively demonstrating highly significant reductions in all-cause mortality, major adverse cardiovascular events (MACE) and the need for coronary artery revascularization procedures (CARPs). More importantly, these benefits of statin therapy are similar at all levels of CVD risk, including subjects at low (<1% per year) risk of a MACE. In addition to preventing myocardial infarction (MI), stroke, and death, primary prevention with statins is also highly effective in delaying and avoiding expensive CARPs such as angioplasties, stents, and bypass surgeries. There is no evidence of any serious harm or threat to life caused by statin therapy, though several adverse effects that affect the quality of life, especially diabetes mellitus (DM) have been reported. Asian Indians have the highest risk of premature coronary artery disease (CAD) and diabetes. When compared with Whites, Asian Indians have double the risk of CAD and triple the risk of DM, when adjusted for traditional risk factors for these diseases. Available evidence supports the use of statin therapy for primary prevention in Asian Indians at a younger age and with lower targets for low-density lipoprotein cholesterol (LDL-C) and non-high density lipoprotein (non-HDL-C), than those currently recommended for Americans and Europeans. Early and aggressive statin therapy offers the greatest potential for reducing the continuing epidemic of CAD among Indians.

Serious statin-associated myotoxicity and rhabdomyolysis in Aboriginal and Torres Strait Islanders: a case series

BACKGROUND

Statins are associated with skeletal muscle adverse effects. These are generally considered mild and reversible, with more severe toxicity occurring rarely. There is little known regarding statin myotoxicity in Aboriginal and Torres Strait Islander Australians who are at high cardiovascular risk and likely to receive statins.

AIMS

To describe features of serious statin-associated myotoxicity (SSAM) occurring in Indigenous Australians and increase awareness of this condition.

METHODS

Observational case series of SSAM in Aboriginal or Torres Strait Islanders. Cases were identified from personal clinical experience, referrals, reports to the Therapeutic Goods Administration, medical literature, an Internet search and reports from a histopathology laboratory. Information was collected onto a standardised data collection form.

RESULTS

Fifteen cases of serious myotoxicity in Aboriginal or Torres Strait Islanders exposed to statins were identified from 2006 to 2012. The mean age was 55 (range 35-69). Painless weakness was the most common presentation. Interacting drugs were involved in seven cases. Biopsies were done in eight cases, three showed inflammatory polymyositis and five necrotising myositis. Three patients died and two had permanent severe disability. Resolution of symptoms after statin cessation was variable.

CONCLUSIONS

SSAM has occurred in the Indigenous Australian population with some fatalities. Awareness of the potential for SSAM is essential for early recognition and effective management to reduce probability of avoidable catastrophic harm. Safe, as well as effective use of medication, is essential for optimum health outcomes. Effective pharmacovigilance and therapeutic risk management are important for Aboriginal and Torres Strait Islander Australians.

Statins and daptomycin: safety assessment of concurrent use and evaluation of drug interaction liability

BACKGROUND

Acute muscle injury and potentially fatal rhabdomyolysis may occur with use of statins and certain interacting medications. This investigation assessed risk for myopathy in patients receiving treatment with a statin in combination with daptomycin, a medication also associated with muscle injury.

METHODS

Patients hospitalized from July 1, 2005, through June 30, 2010, who received simvastatin or rosuvastatin concurrently with daptomycin were identified and their medical records were examined. Patients were judged to have treatment-related muscle injury if their records contained evidence of myalgia with or without weakness and secondarily impaired mobility together with elevated creatine kinase (CK) levels. These assessments were compared with similar data from hospitalized patients who received a statin alone.

RESULTS

A total of 52 patients received 66 courses of concurrent treatment with simvastatin or rosuvastatin and daptomycin. Of these, no patient (0%) met evidentiary requirements for diagnosis of myopathy or related complications. No patient (0%) developed muscle pain or discomfort and none developed markedly elevated CK levels. The incidence of asymptomatic elevations of CK in these simvastatin or rosuvastatin plus daptomycin recipients (9%) was statistically indistinguishable from the incidence of CK elevations found in a cohort of 105 inpatients who received simvastatin or rosuvastatin alone (21%; p=0.135).

CONCLUSIONS

In patients receiving treatment with simvastatin or rosuvastatin and daptomycin, no symptoms or objective evidence of muscle injury attributable to a drug interaction were identified. These findings are consistent with data indicating that the myopathic effects of statins and daptomycin are incited by disparate and perhaps unique pharmacological mechanisms. Risk of muscle injury therefore appears to be no greater when a statin is administered with daptomycin than when either medication is used alone.

Assessment of statin-associated muscle toxicity in Japan: a cohort study conducted using claims database and laboratory information

OBJECTIVE

To estimate the incidence of muscle toxicity in patients receiving statin therapy by examining study populations, drug exposure status and outcome definitions.

DESIGN

A retrospective cohort study.

SETTING

16 medical facilities in Japan providing information on laboratory tests performed in and claims received by their facilities between 1 April 2004 and 31 December 2010.

PARTICIPANTS

A database representing a cohort of 35 903 adult statin (atorvastatin, fluvastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin) users was studied. Use of interacting drugs (fibrates, triazoles, macrolides, amiodarone and ciclosporin) by these patients was determined.

MAIN OUTCOME MEASURE

Statin-associated muscle toxicity (the 'event') was identified based on a diagnosis of muscle-related disorders (myopathy or rhabdomyolysis) and/or abnormal elevation of creatine kinase (CK) concentrations. Events were excluded if the patients had CK elevation-related conditions other than muscle toxicity. Incidence rates for muscle toxicity were determined per 1000 person-years, with 95% CI determined by Poisson regression.

RESULTS

A total of 18 036 patients accounted for 42 193 person-years of statin therapy, and 43 events were identified. The incidence of muscle toxicity in the patients treated with statins was 1.02 (95% CI 0.76 to 1.37)/1000 person-years. The estimates varied when outcome definitions were modified from 0.09/1000 person-years, which met both diagnosis and CK 10× greater than the upper limit of normal range (ULN) criteria, to 2.06/1000 person-years, which met diagnosis or CK 5× ULN criterion. The incidence of muscle toxicity was also influenced by the statin therapies selected, but no significant differences were observed. Among 2430 patients (13.5%) received interacting drugs with statins, only three muscle toxicity cases were observed (incidence: 1.69/1000 person-years).

CONCLUSIONS

This database study suggested that statin use is generally well tolerated and safe; however, the risk of muscle toxicity related to the use of interacting drugs requires further exploration.

Almorexant effects on CYP3A4 activity studied by its simultaneous and time-separated administration with simvastatin and atorvastatin

PURPOSE

To characterise further the previously observed cytochrome P450 3A4 (CYP3A4) interaction of the dual orexin receptor antagonist almorexant.

METHODS

Pharmacokinetic interactions were investigated (n = 14 healthy male subjects in two treatment groups) between almorexant at steady-state when administered either concomitantly or 2 h after administration of single doses of simvastatin (40 mg) or atorvastatin (40 mg).

RESULTS

Almorexant dose-dependently increased simvastatin exposure (AUC0-∞) when administered concomitantly [geometric mean ratios (90 % CI): 2.5 (2.1, 2.9) (100 mg), 3.9 (3.3, 4.6) (200 mg)], but not Cmax [3.7 (3.0, 4.5) for both doses]. Time-separated administration resulted in relevant reductions of the interaction [AUC0-∞: 1.4 (1.2, 1.7) (100 mg), 1.7 (1.5, 2.0) (200 mg); Cmax: 1.5 (1.3, 1.9) (100 mg), 1.9 (1.6, 2.4) (200 mg)]. Similar results were obtained for hydroxyacid simvastatin. Independent of almorexant dose and relative time of administration, AUC0-∞ and Cmax of atorvastatin increased (ratios ranged from 1.1 to 1.5). AUC0-∞ and Cmax of o-hydroxy atorvastatin decreased dose-independently [AUC0-∞: 0.8 (0.8, 0.9) (100 mg), 0.6 (0.5, 0.6) (200 mg); Cmax: 0.3 (0.3, 0.4) (100 mg), 0.2 (0.2, 0.3) (200 mg)] when atorvastatin was concomitantly administered. Cmax of o-hydroxy atorvastatin slightly decreased (0.8 for both doses) following time-separated administration; AUC0-∞ was unchanged.

CONCLUSIONS

Whereas almorexant increased simvastatin exposure dose- and relative time of administration-dependently, atorvastatin exposure increased to a smaller extent and irrespective of dose and time. This suggests that the observed interaction of almorexant with simvastatin is mainly caused by intestinal CYP3A4 inhibition, whereas the interaction with atorvastatin is more due to hepatic CYP3A4 inhibition.

Individualized risk for statin-induced myopathy: current knowledge, emerging challenges and potential solutions

Skeletal muscle toxicity is the primary adverse effect of statins. In this review, we summarize current knowledge regarding the genetic and nongenetic determinants of risk for statin induced myopathy. Many genetic factors were initially identified through candidate gene association studies limited to pharmacokinetic (PK) targets. Through genome-wide association studies, it has become clear that SLCO1B1 is among the strongest PK predictors of myopathy risk. Genome-wide association studies have also expanded our understanding of pharmacodynamic candidate genes, including RYR2. It is anticipated that deep resequencing efforts will define new loci with rare variants that also contribute, and sophisticated computational approaches will be needed to characterize gene-gene and gene-environment interactions. Beyond environment, race is a critical covariate, and its influence is only partly explained by geographic differences in the frequency of known pharmacodynamic and PK variants. As such, admixture analyses will be essential for a full understanding of statin-induced myopathy.

Rhabdomyolysis caused by an unusual interaction between azithromycin and simvastatin

Rhabdomyolysis is an uncommon but life-threatening adverse effect of simvastatin therapy. A 73-year-old male on chronic simvastatin therapy received azithromycin for acute bronchitis. He presented with weakness of all extremities with a significant increase in creatinine phosphokinase levels and acute kidney injury. Simvastatin was stopped and supportive therapy with intravenous saline and bicarbonate was initiated. The serum creatinine and creatine phosphokinase returned to baseline in the next 7 days. Two months later, simvastatin was resumed without any recurrence of symptoms. Our case report highlights the rare description of rhabdomyolysis caused by a drug interaction between simvastatin with azithromycin.

Pharmacokinetic interactions of almorexant with midazolam and simvastatin, two CYP3A4 model substrates, in healthy male subjects

PURPOSE

Pre-clinical experiments have shown that almorexant, a dual orexin receptor antagonist, is able to inhibit cytochrome P450 3A4 (CYP3A4). Therefore, a study was conducted to investigate the effects of multiple-dose almorexant on the pharmacokinetics of midazolam and simvastatin, two CYP3A4 model substrates.

METHODS

Fourteen healthy male subjects were enrolled in an open-label, randomized, two-way crossover study. Treatment period A consisted of a single oral dose of 2 mg midazolam on day 1 and 40 mg simvastatin on day 3. In treatment period B, subjects received 200 mg almorexant once daily for 9 days together with a single oral dose of midazolam on day 7 and simvastatin on day 9.

RESULTS

Concomitant administration of midazolam with almorexant at steady-state levels, achieved within 4-5 days, resulted in an increase of 1.2-fold [90 % confidence interval (CI) 1.0-1.4], 1.4-fold (90 % CI 1.2-1.6), and 1.3-fold (90 % CI 1.2-1.4) in the maximum plasma concentration (C(max)), area under the concentration-time curve from time 0 to infinity (AUC(0-∞)), and terminal half-life (t(1/2)), respectively, of midazolam; the time to peak plasma concentration (t(max)) was unchanged. Whereas C(max) and t(max) were not influenced by almorexant, the AUC(0-∞) of hydroxy-midazolam increased by 1.2-fold (90 % CI 1.1-1.4) and the t(1/2) by 1.3-fold (90 % CI 1.0-1.5). Concomitant administration of simvastatin with almorexant at steady-state resulted in an increase of 2.7-fold (90 % CI 2.0-3.7) and 3.4-fold (90 % CI 2.6-4.4) in C(max) and AUC(0-∞), respectively, for simvastatin; the t(1/2) and t(max) were unchanged. The C(max) and AUC(0-∞) of hydroxyacid simvastatin both increased by 2.8-fold, with 90 % CIs of 2.3-3.5 and 2.2-3.5, respectively; the t(max) increased by 2 h and the t(1/2) was unchanged. The urinary 6-β-hydroxycortisol/cortisol ratio was unaffected by almorexant.

CONCLUSIONS

Our results suggest that the observed interaction was caused by the inhibition of CYP3A4 activity, most probably at the gut level.

The clinical pharmacogenomics implementation consortium: CPIC guideline for SLCO1B1 and simvastatin-induced myopathy

Cholesterol reduction from statin therapy has been one of the greatest public health successes in modern medicine. Simvastatin is among the most commonly used prescription medications. A non-synonymous coding single-nucleotide polymorphism (SNP), rs4149056, in SLCO1B1 markedly increases systemic exposure to simvastatin and the risk of muscle toxicity. This guideline explores the relationship between rs4149056 (c.521T>C, p.V174A) and clinical outcome for all statins. The strength of the evidence is high for myopathy with simvastatin. We limit our recommendations accordingly.

Clinical importance of the drug interaction between statins and CYP3A4 inhibitors: a retrospective cohort study in The Health Improvement Network

OBJECTIVE

To compare the relative hazard of muscle toxicity, renal dysfunction, and hepatic dysfunction associated with the drug interaction between statins and concomitant medications that inhibit the CYP3A4 isoenzyme.

BACKGROUND

Although statins provide important clinical benefits related to mitigating the risk of cardiovascular events, this class of medications also has the potential for severe adverse reactions. The risk for adverse events may be potentiated by concomitant use of medications that interfere with statin metabolism.

METHODS

Data from The Health Improvement Network (THIN) from 1990 to 2008 were used to conduct a retrospective cohort study. Cohorts were created to evaluate each outcome (muscle toxicity, renal dysfunction, and hepatic dysfunction) independently. Each cohort included new statin initiators and compared the relative hazard of the outcome. The interaction ratio (I*R) was the primary contrast of interest. The I*R represents the relative effect of each statin type (statin 3A4 substrate vs. statin non-3A4 substrate) with a CYP3A4 inhibitor, independent of the effect of the statin type without a CYP3A4 inhibitor. We adjusted for confounding variables using the multinomial propensity score.

RESULTS

The median follow-up time per cohort was 1.5 years. There were 7889 muscle toxicity events among 362,809 patients and 792,665 person-years. The adjusted muscle toxicity I*R was 1.22 (95% confidence interval [CI] = 0.90-1.66). There were 1449 renal dysfunction events among 272,099 patients and 574,584 person-years. The adjusted renal dysfunction I*R was 0.91 (95%CI = 0.58-1.44). There were 1434 hepatic dysfunction events among 367,612 patients and 815,945 person-years. The adjusted hepatic dysfunction I*R was 0.78 (95%CI = 0.45-1.31).

CONCLUSIONS

Overall, this study found no difference in the relative hazard of muscle toxicity, renal dysfunction, or hepatic dysfunction for patients prescribed a statin 3A4 substrate versus a statin non-3A4 substrate with CYP3A4 inhibitor concomitancy.

A screening study of drug-drug interactions in cerivastatin users: an adverse effect of clopidogrel

An analysis of a case-control study of rhabdomyolysis was conducted to screen for previously unrecognized cytochrome P450 enzyme (CYP) 2C8 inhibitors that may cause other clinically important drug-drug interactions. Medication use in cases of rhabdomyolysis using cerivastatin (n = 72) was compared with that in controls using atorvastatin (n = 287) for the period 1998-2001. The use of clopidogrel was strongly associated with rhabdomyolysis (odds ratio (OR) 29.6; 95% confidence interval (CI), 6.1-143). In a replication effort that used the US Food and Drug Administration (FDA) Adverse Event Reporting System (AERS), it was found that clopidogrel was used more commonly in patients with rhabdomyolysis receiving cerivastatin (17%) than in those receiving atorvastatin (0%, OR infinity; 95% CI = 5.2-infinity). Several medications were tested in vitro for their potential to cause drug-drug interactions. Clopidogrel, rosiglitazone, and montelukast were the most potent inhibitors of cerivastatin metabolism. Clopidogrel and its metabolites also inhibited cerivastatin metabolism in human hepatocytes. These epidemiological and in vitro findings suggest that clopidogrel may cause clinically important, dose-dependent drug-drug interactions with other medications metabolized by CYP2C8.

Cytochrome P450-mediated cardiovascular drug interactions

INTRODUCTION

There are numerous drug-drug interactions (DDIs) related to cardiovascular medications and many of these are mediated via the cytochrome P450 (CYP) system. Some of these may lead to serious adverse events and it is, therefore, essential that clinicians are aware of the important interactions that occur.

AREAS COVERED

An extensive literature search was performed to analyze the CYP-mediated cardiovascular DDIs that lead to a loss of efficacy or potential toxicity. Cardiovascular drugs may be victims or act as perpetrators of DDIs. The paper analyzes CYP-mediated drug interactions concerning anticoagulants, antiplatelet agents, antiarrhythmics, β-blockers, calcium antagonists, antihypertensive medications, lipid-lowering drugs and oral antidiabetic agents.

EXPERT OPINION

Cardiovascular DDIs involving the CYP system are numerous. Additionally, the spectrum of drugs prescribed is constantly changing, particularly with cardiovascular diseases and it is not necessarily the case that drugs that had shown safety earlier will always show safety. Clinicians are encouraged to develop their knowledge of CYP-mediated DDIs so that they can choose safe drug combination regimens, adjust drug dosages appropriately and conduct therapeutic drug monitoring for drugs with narrow therapeutic indices.

Drug-related myopathies of which the clinician should be aware

Many drugs used for therapeutic interventions can cause unanticipated toxicity in muscle tissue, often leading to considerable morbidity. A drug-induced, or toxic, myopathy is defined as the acute or subacute manifestation of myopathic symptoms such as muscle weakness, myalgia, creatine kinase elevation, or myoglobinuria that can occur in patients without muscle disease when they are exposed to certain drugs. A brief review of agents with a known association with myotoxicity and the proposed mechanisms linked to that toxicity is outlined; however, the purpose of this review is to highlight recent discoveries and advances in the field of toxic myopathies that have practical implications for practicing physicians. Because many drug-related myopathies are potentially reversible at early stages, it is important for clinicians to recognize toxic myopathies early in their course to determine when to discontinue therapy and potentially prevent irreversible muscle damage.