Rhabdomyolysis associated with concomitant use of atorvastatin and cyclosporine

Asymptomatic COVID-19 Infection-Induced Rhabdomyolysis in the Backdrop of Statin-Cyclosporine Drug Interaction

Rhabdomyolysis involves skeletal muscle breakdown leading to high serum creatine kinase (CK) levels and myoglobinuria. Here, we report the case of a middle-aged man who developed rhabdomyolysis, resulting in acute kidney injury (AKI) over pre-existing chronic kidney disease (stage 3a) secondary to focal segmental glomerulosclerosis (primary FSGS), during an asymptomatic COVID-19 infection. The patient had been on treatment with cyclosporine and statin, among other drugs, for his comorbidities. He had initially presented to the hospital after a fall due to difficulty walking in the setting of increasing edema. Lab workup revealed elevated CK and AKI. Urinalysis showed "large" blood on a dipstick with only two RBCs per high-power field on microscopy, suggesting myoglobinuria. A standard respiratory pathogen polymerase chain reaction panel revealed positive SARS-CoV-2. The chest X-ray and oxygenation were normal, and he had no respiratory symptoms. He was treated with intravenous fluids and albumin, with a steady improvement in renal function. Our case underlines that rhabdomyolysis can occur in asymptomatic COVID-19 infection. Therefore, it may be worth monitoring CK levels in COVID-19-positive patients with risk factors for rhabdomyolysis, such as the concurrent usage of statins and cyclosporine, even if they are otherwise asymptomatic.

Clinical conundrums involving statin drug-drug interactions

Statins are the cornerstone of pharmacologic therapy for the prevention and treatment of atherosclerotic cardiovascular disease. While they are generally considered safe, statins can be affected by drug-drug interactions (DDIs) that increase their systemic exposure increasing the risk for statin-associated muscle symptoms. These interactions are primarily mediated through metabolizing enzymes such as cytochrome P450 isoenzymes and membrane-bound drug transporting proteins including P-glycoprotein and organic ion transporting polypeptide. Recognition and avoidance of clinically significant statin DDIs is important to ensure their safe use. Conversely, concern over statin DDIs that are not clinically significant may lead to inappropriate underutilization or avoidance of statins in patients who would benefit from them. While many statin DDIs are well-characterized, we present several others that are less-well-established which may warrant clinical attention.

Systemic lupus erythematosus presenting as hyponatremia-associated rhabdomyolysis: A case report

RATIONALE

Systemic lupus erythematosus (SLE) is an autoimmune disease that involves multiple organs and causes various clinical manifestations. Cases of rhabdomyolysis as the initial presentation of SLE are rare, and there are no reported cases of SLE presenting hyponatremia-associated rhabdomyolysis as the first manifestation. Herein, we report a case of SLE with lupus nephritis in a patient with acute hyponatremia-associated rhabdomyolysis.

PATIENT CONCERNS

A 44-year-old woman was admitted with complaints of altered consciousness, myalgia, and red-brownish urine that first appeared three days prior. Peripheral blood tests revealed elevated creatine kinase (19,013 IU/L) and myoglobin (5099 U/L) levels and severe hyponatremia (111 mEq/L) with no azotemia. Urinalysis showed nephritic sediments.

DIAGNOSIS

Whole-body bone scintigraphy showed increased uptake of radiotracer in the both upper and lower extremities. Serological evaluation revealed the presence of anti-nuclear (speckled pattern, 1:640), anti-double stranded DNA, and anti-Smith antibodies and absence of anti-Jo-1 antibody. A kidney biopsy demonstrated mesangial proliferative (class II) lupus nephritis.

INTERVENTIONS

Fluid therapy, including intravenous administration of 3% NaCl, was initiated. After three consecutive days of intravenous methylprednisolone (1 g/d), oral prednisolone (1 mg/kg/d), mycophenolate mofetil, and hydroxychloroquine were administered.

OUTCOMES

On day 28, the patient was discharged with marked resolution of SLE-associated symptoms and laboratory findings. Lupus reactivation was not present during the subsequent six-month follow-up.

LESSONS

Hyponatremia-associated rhabdomyolysis can be the first manifestation of SLE. Moreover, prompt fluid therapy and timely administration of immunosuppressive agents in SLE patients presenting with hyponatremia and rhabdomyolysis can significantly help alleviate disease activity and improve clinical outcomes.

Prediction of pharmacokinetic drug-drug interactions causing atorvastatin-induced rhabdomyolysis using physiologically based pharmacokinetic modelling

Atorvastatin and its lactone form metabolite are reported to be associated with statin-induced myopathy (SIM) such as myalgia and life-threatening rhabdomyolysis. Though the statin-induced rhabdomyolysis is not common during statin therapy, its incidence will significantly increase due to pharmacokinetic drug-drug interactions (DDIs) with inhibitor drugs which inhibit atorvastatin's and its lactone's metabolism and hepatic uptake. Thus, the quantitative analysis of DDIs of atorvastatin and its lactone with cytochrome P450 3A4 (CYP3A4) and organic anion-transporting polypeptide (OATP) inhibitors is of great importance. This study aimed to predict pharmacokinetic DDIs possibly causing atorvastatin-induced rhabdomyolysis using Physiologically Based Pharmacokinetic (PBPK) Modelling. Firstly, we refined the PBPK models of atorvastatin and atorvastatin lactone for predicting the DDIs with CYP3A4 and OATP inhibitors. Thereafter, we predicted the exposure changes of atorvastatin and atorvastatin lactone originating from the case reports of atorvastatin-induced rhabdomyolysis using the refined models. The simulation results show that pharmacokinetic DDIs of atorvastatin and its lactone with fluconazole, palbociclib diltiazem and cyclosporine are significant. Consequently, clinicians should be aware of necessary dose adjustment of atorvastatin being used with these four inhibitor drugs.

Clinical Controversy in Transplantation: Tacrolimus Versus Cyclosporine in Statin Drug Interactions

Objective: To review the available literature that provides evidence for the absence of statin interactions with tacrolimus compared with cyclosporine. Data Sources: A literature search of PubMed was performed (1990 to June 2019) using the following search terms: calcineurin inhibitors, tacrolimus, cyclosporine, statins, atorvastatin, simvastatin, and drug interactions. Clinical practice guidelines, article bibliographies, drug interaction database references, and product monographs were also reviewed. Study Selection and Data Extraction: Relevant English-language studies describing the mechanism of interaction, the magnitude of pharmacokinetic alterations, and safety were evaluated. In vitro data and studies conducted in adult humans were considered. Data Synthesis: Studies demonstrate pharmacokinetic differences between cyclosporine and tacrolimus, particularly with regard to inhibition of 2 hepatic transporters: P-glycoprotein and organic anion transporting polypeptide (OATP). Compared with cyclosporine, tacrolimus does not affect these transporters, does not enhance statin exposure, and does not increase statin-associated safety events. Relevance to Patient Care and Clinical Practice: Clinical practice guidelines allude to the need to reduce statin doses in the setting of tacrolimus. Some providers have adopted this practice, and doing so may prevent transplant recipients from attaining cardiovascular benefit, especially when increased or high-intensity doses are required. The pharmacokinetic differences between tacrolimus and cyclosporine highlight different interaction potential with statins. Conclusions: Clinicians need to be aware that tacrolimus and cyclosporine are not the same with regard to causing drug interactions with statins. Tacrolimus can be used with statins without the need for dose adjustments because of lack of an interaction.

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.

Drug-Induced Rhabdomyolysis Atlas (DIRA) for idiosyncratic adverse drug reaction management

Drug-induced rhabdomyolysis (DIR) is an idiosyncratic and fatal adverse drug reaction (ADR) characterized in severe muscle injuries accompanied by multiple-organ failure. Limited knowledge regarding the pathophysiology of rhabdomyolysis is the main obstacle to developing early biomarkers and prevention strategies. Given the lack of a centralized data resource to curate, organize, and standardize widespread DIR information, here we present a Drug-Induced Rhabdomyolysis Atlas (DIRA) that provides DIR-related information, including: a classification scheme for DIR based on drug labeling information; postmarketing surveillance data of DIR; and DIR drug property information. To elucidate the utility of DIRA, we used precision dosing, concomitant use of DIR drugs, and predictive modeling development to exemplify strategies for idiosyncratic ADR (IADR) management.

High-Intensity Atorvastatin-Induced Rhabdomyolysis in an Elderly Patient With NSTEMI: A Case Report and Review of the Literature

A 91-year-old male was admitted to the hospital for worsening muscle weakness, muscle pain, and unexplained soreness for the past 10 days. Four months prior to his admission, the patient had experienced a myocardial infarction and was initiated on atorvastatin 80 mg daily. Although the provider had instructed the patient to decrease the atorvastatin dose to 40 mg daily 3 months prior to admission, the patient did not adhere to the lower dose regimen until 10 days prior to hospitalization. Upon admission, the patient presented with muscle weakness and pain, a serum creatinine phosphokinase of 18 723 U/L, and a serum creatinine of 1.6 mg/dL. The atorvastatin dose was held and the patient was treated with intravenous fluids. The 2013 American College of Cardiology and American Heart Association Blood Cholesterol Practice Guidelines recommend the use of moderate-intensity statins in patients older than 75 years to prevent myopathy. However, in clinical practice, aggressive statin therapy is often prescribed for significant coronary disease. Prescribing high-intensity statins for patients with advanced age, such as this case, may increase the risk of rhabdomyolysis and other complications. This case report suggests that providers should avoid or be cautious with initiating high-intensity atorvastatin in elderly patients over 75 years to minimize the risk of rhabdomyolysis.

Clinical Pharmacist Patient-Safety Initiative to Reduce Against-Label Prescribing of Statins With Cyclosporine

BACKGROUND

Against-label prescribing of statins with interacting drugs, such as cyclosporine, represents an important patient safety concern.

OBJECTIVE

To implement and evaluate the effectiveness of a clinical pharmacist patient-safety initiative to minimize against-label prescribing of statins with cyclosporine.

METHODS

Kaiser Permanente Colorado clinical pharmacists identified patients receiving both cyclosporine and against-label statin through prescription claims data. Academic detailing on this interaction was provided to health care providers. Clinical pharmacists collaborated with physicians to facilitate conversion to on-label statin. Conversion rates along with changes in low-density lipoprotein cholesterol (LDL-C) were assessed.

RESULTS

Of the 157 patients identified as taking cyclosporine, 48 were receiving concurrent statin therapy. Of these 48 patients, 33 (69%) were on an against-label statin regimen; 25 (76%) of these patients were converted to on-label statin. Overall, patients converted to on-label statin had a mean LDL-C prior to conversion of 82.9 (±26.4) mg/dL and mean LDL-C after conversion of 90.7 (±31.2) mg/dL ( P = 0.21). In all, 17 patients (68%) were switched to pravastatin 20 mg daily and 8 patients (32%) to rosuvastatin 5 mg daily. In patients converted to pravastatin 20 mg daily, the mean LDL-C was 13.5 mg/dL higher than prior to conversion ( P = 0.066). In patients converted to rosuvastatin 5 mg daily, the mean LDL-C was 3.8 mg/dL lower than prior to conversion ( P = 0.73).

CONCLUSION

Utilizing a patient-safety-centered approach, clinical pharmacists were able to reduce the number of patients on against-label statin with cyclosporine while maintaining a comparable level of LDL-C control.

Statins: immunomodulators for autoimmune rheumatic disease?

Inhibitors of 3-hydroxy-3-methylgluttaryl coenzyme A (HMG-CoA) reductase, or statins, are used extensively to reduced elevated lipid levels and reduce cardiovascular risk. However, accumulated evidence suggests that stains not only act by lowering cholesterol levels, but also exert pleiotropic effects on many essential cellular functions including cell proliferation, differentiation, and survival and participate in the regulation of cell shape and motility. Thus cardiovascular benefit is provided by lowering raised cholesterol levels and by modulation of the inflammatory component of this disease. Such an anti-inflammatory effect may also benefit patients with autoimmune rheumatic disease. This overview assesses the evidence for using statins in patients with rheumatoid arthritis and systemic lupus erythematosus (SLE).

Rhabdomyolysis with Concurrent Atorvastatin and Diltiazem

OBJECTIVE:

To report a case of rhabdomyolysis and acute hepatitis associated with the coadministration of atorvastatin and diltiazem.

CASE SUMMARY:

A 60-year-old African American man with a significant past medical history presented to the emergency department with acute renal failure secondary to rhabdomyolysis. In addition, liver enzymes were elevated to greater than 3 × normal. The only change in medication was the initiation of diltiazem 3 weeks earlier for atrial fibrillation to a complicated medication regimen that included atorvastatin.

DISCUSSION:

Rhabdomyolysis has been reported in patients receiving hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors when coadministered with agents that may inhibit their metabolism. Atorvastatin is the most potent of this class of agents currently available and is commonly used in the treatment of hyperlipidemia. Rhabdomyolysis resulting from the drug interaction between diltiazem and other HMG-CoA reductase inhibitors has been described in the literature. However, no report has specifically associated this adverse event with atorvastatin and diltiazem. We describe a patient with a complex medication regimen who was admitted for rhabdomyolysis and accompanying acute renal failure, along with acute hepatitis, thought to be secondary to a drug interaction between atorvastatin and diltiazem.

CONCLUSIONS:

While optimizing the patient's lipid profile should be the primary factor in choosing one statin over another, the potential for drug interactions requires close attention. All patients beginning HMG-CoA reductase inhibitor therapy should be counseled regarding the signs and symptoms of muscle injury; particular attention should be paid to those patients who are taking medications that may interact.

Rhabdomyolysis as a clinical manifestation of association with ciprofibrate, sirolimus, cyclosporine, and pegylated interferon-α in liver-transplanted patients: a case report and literature review

BACKGROUND

Rhabdomyolysis is a syndrome characterized by impaired metabolic integrity of myocytes, causing the release of intracellular constituents into the circulation, and can be a serious side effect of drug intake.

CASE REPORT

This report describes a unique case of rabdomyolysis secondary in which ciprofibrate, sirolimus, cyclosporine, and pegylated interferon-α in a liver transplant patient was used. A 47-year-old male liver transplant recipient in 2009, who had hepatitis C and incidental hepatocellular carcinoma, underwent immunosuppressive therapy (cyclosporine and sirolimus). The patient is currently in treatment for viral recurrence with pegylated interferon-α and ribavirin; he had a history of hypertriglyceridemia treated with ciprofibrate. He had development of severe and generalized myalgia and fever after the eighth application of pegylated interferon-α and increasing doses of cyclosporine. Laboratorial tests showed acute renal failure and significant increase in creatine kinase. Rhabdomyolysis secondary to interaction of fibrate-cyclosporine-pegylated interferon-α was postulated.

CONCLUSIONS

Medical professionals should be aware of possible drug interactions and should monitor patients receiving these drugs.

Increased dosage of cyclosporine induces myopathy with increased seru creatine kinase in an elderly patient on chronic statin therapy

WHAT IS KNOWN AND OBJECTIVE

The concomitant administration of atorvastatin and cyclosporine has been shown to increase the serum concentration of 3-hydroxy-3-methylglutaryl coenzyme A, which may be associated with the elevation of creatine kinase and an increased risk of myopathy. Our objective is to report on a case of statin-induced myopathy associated with concomitant use of cyclosporine and other contributing factors.

CASE SUMMARY

An 88-year-old Chinese male patient with comorbidities received polypharmacy treatment, including atorvastatin and cyclosporine. After the dosage of cyclosporine was increased to 300 mg every day for 8 months, the patient developed body pain and leg weakness, with a serum creatine kinase increase and evidence on magnetic resonance imaging of muscle oedema.

WHAT IS NEW AND CONCLUSION

Cyclosporine is a moderate inhibitor of the cytochrome P450 CYP3A4 isoenzyme, which is known to increase the serum level of atorvastatin. We hypothesized that the pharmacological and pharmacokinetic properties of atorvastatin-induced myopathy are the result of its interaction with high dosage of cyclosporine.

Modeling the effects of commonly used drugs on human metabolism

Metabolism contributes significantly to the pharmacokinetics and pharmacodynamics of a drug. In addition, diet and genetics have a profound effect on cellular metabolism with respect to both health and disease. In the present study, we assembled a comprehensive, literature-based drug metabolic reconstruction of the 18 most highly prescribed drug groups, including statins, anti-hypertensives, immunosuppressants and analgesics. This reconstruction captures in detail our current understanding of their absorption, intracellular distribution, metabolism and elimination. We combined this drug module with the most comprehensive reconstruction of human metabolism, Recon 2, yielding Recon2_DM1796, which accounts for 2803 metabolites and 8161 reactions. By defining 50 specific drug objectives that captured the overall drug metabolism of these compounds, we investigated the effects of dietary composition and inherited metabolic disorders on drug metabolism and drug-drug interactions. Our main findings include: (a) a shift in dietary patterns significantly affects statins and acetaminophen metabolism; (b) disturbed statin metabolism contributes to the clinical phenotype of mitochondrial energy disorders; and (c) the interaction between statins and cyclosporine can be explained by several common metabolic and transport pathways other than the previously established CYP3A4 connection. This work holds the potential for studying adverse drug reactions and designing patient-specific therapies.

Severe rhabdomyolysis associated with concurrent use of simvastatin and sirolimus after cisplatin-based chemotherapy in a kidney transplant recipient

OBJECTIVES

Cardiovascular disease is the most common cause of sickness and death for long-term kidney transplant recipients, and dyslipidemia is an important risk factor for developing cardiovascular disease. Lipid-lowering strategies, with the use of statins, have been shown to reduce the cardiovascular risks related to dyslipidemia, but concomitant use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and immunosuppressive agents may increase the risk of rhabdomyolysis owing to a drug-drug interaction. We report a case of simvastatin-induced rhabdomyolysis and acute kidney injury triggered by addition of sirolimus and cisplatin-based chemotherapy to a kidney transplant recipient who had previously tolerated chronic statin therapy.

Rhabdomyolysis developing secondary to atorvastatin therapy in a patient with liver cirrhosis

Atorvastatin is a lipid lowering agent that is widely used worldwide. Rhabdomyolysis is a rare but serious side effect that may lead to renal failure and dangerous electrolyte abnormalities in patients with decreased hepatic clearance of atorvastatin. We herein report the case of a patient with liver cirrhosis receiving atorvastatin therapy for ischemic heart disease and hyperlipidemia who developed rhabdomyolysis and acute renal failure.

[Drug-drug interactions in antirheumatic treatment]

Clinically relevant drug-drug interactions contribute considerably to potentially dangerous drug side-effects and are frequently the reason for hospitalization. Nevertheless they are often overlooked in daily practice. For most antirheumatic drugs a vast number of interactions have been described but only a minority with clinical relevance. Several potentially important drug interactions exist for non-steroidal anti-inflammatory drugs (NSAIDs), methotrexate, azathioprine, mycophenolate-mofetil and especially for cyclosporin A. Most importantly co-medication with methotrexate and sulfmethoxazole trimethoprim as well as azathioprine and allopurinol carries the risk of severe, sometimes life-threatening consequences. Nevertheless, besides these well-known high-risk combinations in each case of polypharmacy with antirheumatic drugs it is necessary to bear in mind the possibility of drug interactions. As polypharmacy is a common therapeutic practice in older patients with rheumatic diseases, they are at special risk.

Transporter-mediated drug-drug interactions

Drug-drug interactions are a serious clinical issue. An important mechanism underlying drug-drug interactions is induction or inhibition of drug transporters that mediate the cellular uptake and efflux of xenobiotics. Especially drug transporters of the small intestine, liver and kidney are major determinants of the pharmacokinetic profile of drugs. Transporter-mediated drug-drug interactions in these three organs can considerably influence the pharmacokinetics and clinical effects of drugs. In this article, we focus on probe drugs lacking significant metabolism to highlight mechanisms of interactions of selected intestinal, hepatic and renal drug transporters (e.g., organic anion transporting polypeptide [OATP] 1A2, OATP2B1, OATP1B1, OATP1B3, P-gp, organic anion transporter [OAT] 1, OAT3, breast cancer resistance protein [BCRP], organic cation transporter [OCT] 2 and multidrug and toxin extrusion protein [MATE] 1). Genotype-dependent drug-drug interactions are also discussed.

Fatal rhabdomyolysis in systemic lupus erythematosus

The authors describe herein the sixth lupus case that evolved with rhabdomyolysis. A 36-year-old woman with systemic lupus erythematosus was admitted to our hospital with malaise, myalgia, dysphagia, fever, preserved muscle strength, leukocytosis (15,600 cells), and increased creatine kinase of 1,358 IU/L that reached 75,000 IU/L in few days. She denied the use of myotoxic drugs and alcohol. Urine 1 showed false positive for hemoglobinuria (myoglobin) without erythrocytes in the sediment, confirming the diagnosis of rhabdomyolysis. Secondary causes were excluded. She was treated with hyperhydration and alkalinization of urine. Despite treatment, the patient developed pulmonary congestion and she died. The authors also review in this article rhabdomyolysis in patients with systemic lupus erythematosus.

Transplantation in diabetic kidney failure patients: modalities, outcomes, and clinical management

Diabetes mellitus (DM) is a common and devastating disease, affecting up to 19.3 million Americans. It is the leading cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in the United States. Diabetic patients with ESRD have a high incidence of cardiovascular disease and death. For those kidney transplant patients with no history of DM prior to transplantation, the development of new onset diabetes after transplantation (NODAT) also poses a serious threat to both graft and patient survival. Kidney transplantation is the best renal replacement option for diabetic ESRD and has the potential to halt the progression of cardiovascular diseases. Early referral for transplant evaluation is essential for pre-emptive or early kidney transplantation in this cohort of patients. In type 1 DM patients with ESRD, simultaneous pancreas and kidney transplantation (SPK) should be encouraged; and in patients facing prolonged waiting time for SPK transplantation but with an available living donor, living donor kidney transplantation followed by pancreas after kidney transplantation (PAK) is a suitable alternative. Islet transplantation in type 1 diabetics is deemed experimental by Medicare, and easy access to this modality remains restricted to qualified patients enrolled in clinical trials or with private insurance. The optimal management of kidney transplant patients with pre-existent DM or NODAT involves a multi-pronged approach consisting of pharmacological and nonpharmacological intervention to address all potential cardiovascular risk factors such as glycemic and lipid control, blood pressure control, weight loss, and smoking cessation. Finally, re-transplantation should be recommended in suitable kidney transplant patients when the kidney allograft demonstrates continuous and progressive decline in function.

Incidence, predictors and associated outcomes of rhabdomyolysis after kidney transplantation

BACKGROUND

There are several case reports of rhabdomyolysis (RM) in renal transplant recipients, but the actual incidence of this complication is not known. Most of the reported cases have been attributed to drug-drug interactions with calcineurin inhibitors, with the majority of interactions reported between cyclosporine and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins). Pharmacokinetic studies have demonstrated that cyclosporine increases statin drug levels, presumably via competitive inhibition of cytochrome P450 3A4.

METHODS

In a retrospective cohort of 20 366 adult Medicare primary renal transplant recipients in the USRDS database transplanted from 1 January 2003 to 31 July 2005 and followed through 31 December 2005, we assessed Medicare claims for RM and dyslipidaemia (HPL), which was used as a surrogate for statin use.

RESULTS

The incidence rate of RM post-transplant for the study period was 1.4 (95% CI 1.1-1.8) per 1000 person-years. By Cox regression analysis, cyclosporine (versus tacrolimus) use [AHR 2.36 (95% CI 1.23-4.35); P = 0.006] and black race [AHR 2.33 (95% CI 1.30-4.17); P = 0.005] were associated with RM. By Cox non-proportional hazards regression, RM was associated with graft loss (including death) [AHR 2.84 (95% CI 1.70-4.72); P < 0.001].

CONCLUSIONS

RM is a rare complication after renal transplantation and is significantly associated with allograft loss (including death). RM is significantly more likely to occur with cyclosporine (versus tacrolimus)-based immunosuppression and possibly in persons of black race. Increased surveillance for RM is warranted in these at-risk patients.

Differential effects of tipranavir plus ritonavir on atorvastatin or rosuvastatin pharmacokinetics in healthy volunteers

To identify pharmacokinetic (PK) drug-drug interactions between tipranavir-ritonavir (TPV/r) and rosuvastatin and atorvastatin, we conducted two prospective, open-label, single-arm, two-period studies. The geometric mean (GM) ratio was 1.37 (90% confidence interval [CI], 1.15 to 1.62) for the area under the concentration-time curve (AUC) for rosuvastatin and 2.23 (90% CI, 1.83 to 2.72) for the maximum concentration of drug in serum (Cmax) for rosuvastatin with TPV/r at steady state versus alone. The GM ratio was 9.36 (90% CI, 8.02 to 10.94) for the AUC of atorvastatin and 8.61 (90% CI, 7.25 to 10.21) for the Cmax of atorvastatin with TPV/r at steady state versus alone. Tipranavir PK parameters were not affected by single-dose rosuvastatin or atorvastatin. Mild gastrointestinal intolerance, headache, and mild reversible liver enzyme elevations (grade 1 and 2) were the most commonly reported adverse drug reactions. Based on these interactions, we recommend low initial doses of rosuvastatin (5 mg) and atorvastatin (10 mg), with careful clinical monitoring of rosuvastatin- or atorvastatin-related adverse events when combined with TPV/r.

Effects of cyclosporin A and itraconazole on the pharmacokinetics of atorvastatin in rats

AIM

To evaluate the effects of cyclosporin A and itraconazole, which were used as inhibitors of P-glycoprotein (P-gp) and/or cytochrome P450 (CYP) 3A4 on the pharmacokinetics of atorvastatin in rats.

METHODS

The pharmacokinetic parameters of atorvastatin were measured after intravenous (2 mg/kg) and intragastric (10 mg/kg) administration of atorvastatin in rats, which were pretreated with cyclosporin A (5, 10, and 20 mg/kg) or itraconazole (5, 10, and 20 mg/kg).

RESULTS

Compared with the control rats, cyclosporin A and itraconazole altered the pharmacokinetics of atorvastatin significantly. The AUC0-t values of atorvastatin after intragastric administration, pretreated with cyclosporin A (5-20 mg/kg), increased by 32.3%, 61.8%, and 187.2%, respectively, but the CLbile values decreased (P<0.01, 5-20 mg/kg). With pretreatment of itraconazole (5-20 mg/kg), the AUC(0-t) values of atorvastatin increased by 88.2%, 102%, and 123%, respectively, but the CL(bile) values decreased (P<0.01, 5-20 mg/kg).

CONCLUSION

These data indicated that cyclosporin A could be effective in inhibiting the efflux of atorvastatin, and itraconazole could be effective in inhibiting both the metabolism and biliary excretion of atorvastatin.

[Bilateral leg compartment syndrome due to severe myonecrosis caused by inappropriate use of simvastatin]

Bilateral leg compartment syndrome due to myonecrosis caused by inappropriate use of statins is a rare but potentially fatal complication of this lipid lowering medication. We report a case of a 39-year-old woman who presented with suspicious critical lower limb ischemia. Subsequently, bilateral leg compartment syndrome and myonecrosis developed. The primary cause of myonecrosis was due to misuse of simvastatin mistaken by the patient for a weight-reducing drug. Urgent fasciotomies were performed and the patient underwent urgent renal replacement therapy with continuous hemodialysis for acute renal failure due to myoglobinuria. After this complex treatment, the patient was discharged. She almost fully recovered with only a residual paresis of the left fibular nerve. According to literature, this is a unique case of bilateral compartment syndrome and myonecrosis with acute renal failure due to statin overdose leading to acute renal failure and bilateral fasciotomy.

Management of cardiovascular disease in renal transplant recipients

Cardiovascular disease is a major cause of graft loss and the leading cause of death in renal transplant recipients. Although there are robust data on the frequency of risk factors and their contributions to cardiovascular disease in this population, few trials have demonstrated the benefit of modifying these risk factors to reduce cardiovascular events. Nevertheless, it is widely accepted that the clinical acumen filtered through the best available studies in the general population be used to treat individual renal transplant recipients given their high cardiovascular mortality. Transplant task forces and the Kidney Disease Outcomes Quality Initiative have created guidelines for this purpose. This review examines the data available for prevention and treatment of major risk factors contributing to cardiovascular disease in renal transplant recipients. The contribution of immunosuppressive agents to each risk factor and the evidence to support lifestyle modification as well as drug therapy are examined. Reducing cardiovascular risk factors requires an integrative approach that is best accomplished by a team of health care professionals. It creates a significant challenge but one that must be met if allograft survival is to improve.

Safety and effects on the lipid and C-reactive protein plasma concentration of the association of ezetimibe plus atorvastatin in renal transplant patients treated by cyclosporine-A: a pilot study

Ezetimibe (E) is a new cholesterol adsorption inhibitor which prevents the adsorption of dietary and biliary cholesterol by binding to a recently described cholesterol transporter. This pilot study was performed to evaluate the safety and the low-density lipoprotein (LDL)-C and C-reactive protein lowering efficacy of atorvastatin (A) and of the association of A plus E in five renal transplant patients with hypercholesterolemia and mild renal functional impairment receiving cyclosporine-A (CsA). Patients received for three periods, each of 3 weeks, A at a dose of 20 mg/day; A at a dose of 10 mg/day and finally, A 10 mg plus E 10 mg daily. The medications were well-tolerated and no important clinical or laboratory (muscle enzyme, creatinine clearance and CsA concentration) abnormalities were observed throughout the study period. A alone lead to target LDL-C values only in two of five patients and did not significantly reduce the mean CRP values. The combination of E plus A produced the lowest lipid levels and significantly reduced CRP mean values and allowed all patients to attain target levels of LDL-C: total cholesterol decreased from 240 +/- 42 (mean +/- S.D.) to 171 +/- 34 mg/dl, LDL-C from 129 +/- 32 to 87 +/- 21 mg/dl, plasma triglycerides from 330 +/- 54 to 194 +/- 71 mg/dl and CRP from 6.2 +/- 1.9 to 3.9 +/- 2.4 mg/l (P < 0.05 for all). This pilot study suggests that the co-administration of E and A at 10 mg/day in renal transplant patients receiving CsA is well-tolerated and effective in reducing important cardiovascular risk factors.

Statins' dosage in patients with renal failure and cyclosporine drug-drug interactions in transplant recipient patients

Dyslipidemia is frequent in patients with renal failure and in transplant recipient patients. This lead to a wide use of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) in patients with impaired renal function or in patients treated with cyclosporine as post-transplantation immunosuppressive therapy. As a result, it is crucial for those patients' physicians to be aware of how to handle these drugs when renal function is impaired and/or when cyclosporine is co-administered. Most statins have an extensive hepatic elimination and the renal route is usually a minor elimination pathway. However, pharmacokinetic alterations have been described for some of these drugs in patients with renal insufficiency. Cyclosporine is a widely used immunosuppresive therapy in solid organ transplant patients and drug-drug interactions are likely to occur when statins and cyclosporine are administered together. Those interactions may theoretically result in increased statins and/or cyclosporine serum levels with potential muscle and/or renal toxicity. As a result, caution is warranted if concurrent administration is performed. In this review, we synthesized the data from the literature on (1) the pharmacokinetics and dosage adjustment of atorvastatin, fluvastatin, pravastatin, rosuvastatin, and simvastatin in patients with renal failure and (2) the potential drug-drug interactions between these drugs and cyclosporine in transplant recipient patients.

Preventing cardiovascular outcome in patients with renal impairment: is there a role for lipid-lowering therapy?

Patients with chronic kidney disease (CKD), ranging from modest renal impairment to dialysis and transplant, have an increased risk for cardiovascular disease (CVD). Patients with CKD have both traditional and non-traditional risk factors for CVD. The role of lipids as risk factors for CVD in these populations has not been firmly established. In a recent prospective controlled trial, it was established that atherogenic lipids are indeed strong risk factors for CVD in renal transplant recipients, and that treatment with a HMG-CoA reductase inhibitor reduced the incidence of cardiac death and myocardial infarction. For patients receiving dialysis, the association between serum lipid levels and cardiovascular outcome is uncertain and there is no evidence from controlled trials that lipid-lowering therapy does have a beneficial effect on cardiovascular outcome in these patients. Atherogenic lipids are probably a risk factor for patients with mild or moderate CKD, and five subgroup analyses have indicated a favorable effect of lipid-lowering therapy on cardiovascular outcome, although we still lack prospective controlled trials in these patients. CVD in patients with CKD has been a neglected area of research.

Comparative pharmacokinetic interaction profiles of pravastatin, simvastatin, and atorvastatin when coadministered with cytochrome P450 inhibitors

Three-hydroxy-3-methylglutaryl coenzyme-A reductase inhibitors (statins) are first-line treatments for hypercholesterolemia. Although exceedingly well tolerated, treatment with statins incurs a small risk of myopathy or potentially fatal rhabdomyolysis, particularly when coadministered with medications that increase their systemic exposure. Studies compared the multiple-dose pharmacokinetic interaction profiles of pravastatin, simvastatin, and atorvastatin when coadministered with 4 inhibitors of cytochrome P450-3A4 isoenzymes in healthy subjects. Compared with pravastatin alone, coadministration of verapamil, mibefradil, or itraconazole with pravastatin was associated with no significant changes in pravastatin pharmacokinetics. However, concomitant verapamil increased the simvastatin area under the concentration:time curve (AUC) approximately fourfold, the maximum serum concentration (C(max)) fivefold, and the active metabolite simvastatin acid AUC and C(max) approximately four- and threefold, respectively (all comparisons p <0.001). Similar (greater than fourfold) important increases in these parameters and a >60% increase in the serum half-life (p = 0.03) of atorvastatin were observed when coadministered with mibefradil. The half-life of atorvastatin also increased by approximately 60% (p = 0.052) when coadministered with itraconazole, which elicited a 2.4-fold increase in the C(max) of atorvastatin and a 47% increase in the AUC (p <0.001 for C(max) and AUC). Clarithromycin significantly (p <0.001) increased the AUC (and C(max)) of all 3 statins, most markedly simvastatin ( approximately 10-fold increase in AUC) and simvastatin acid (12-fold), followed by atorvastatin (greater than fourfold) and then pravastatin (almost twofold). Pravastatin has a neutral drug interaction profile relative to cytochrome P450-3A4 inhibitors, but these substrates markedly increase systemic exposure to simvastatin and atorvastatin.

Rhabdomyolysis associated with hydroxymethylglutaryl-coenzyme A reductase inhibitors

BACKGROUND

The recent withdrawal of cerivastatin by the manufacturer has led to an interest in hydroxymethylglutaryl-coenzyme A (HMG-CoA) inhibitors and the incidence of myopathy. We review the epidemiology, pharmacology, and presumed mechanisms of statin-induced myopathy, with a particular focus on cerivastatin.

METHODS

A MEDLINE search of English-language articles published between 1985 and 2003 was performed. Key words included HMG-CoA inhibitors, statins, myopathy, myotoxicity, rhabdomyolysis, adverse events, drug interactions, and cerivastatin.

RESULTS

The initial trials, which assessed the efficacy of first-generation HMG-CoA inhibitors, did not show a clinically significant increase in the incidence of myopathy. However, on the basis of Food and Drug Administration post-marketing surveys, the rate of cerivastatin-induced rhabdomyolysis appeared to be 10-fold greater than that of the other statins, despite safe pre-clinical profiles. However, no clinical trials have been performed directly comparing the rates of myotoxicity of all commercially available statins. The mechanism of statin-induced myopathy remains unclear. The prevailing theory is that lipophilic statins lead to depletion of intermediates normally formed after cholesterol synthesis within myocytes. Risk factors for the development of myopathy include drug interactions (especially with fibrates) and the coexistence of conditions known to predispose patients to rhabdomyolysis.

CONCLUSION

The cerivastatin experience emphasizes the need for large safety trials before drug approval and for vigilant post-marketing surveillance. Further research and sound clinical judgment may lead to the identification of high-risk individuals in whom statins should be avoided.

Efficacy and safety of fluvastatin therapy for hypercholesterolemia after heart transplantation

BACKGROUND

Hypercholesterolemia is frequent after heart transplantation. Statins can reduce cholesterol levels but their use in heart transplant patients is complicated by pharmacokinetic interactions with cyclosporin and the risk of serious adverse effects including rhabdomyolysis. Fluvastatin has been used safely to treat hypercholesterolemia in renal transplant patients but there are few data relating to its use after heart transplantation. Therefore, we conducted a randomised blinded placebo controlled trial.

METHODS AND RESULTS

Seventy-nine patients, 3 months to 12 years after heart transplantation with a low density lipoprotein (LDL) cholesterol between 3.5 and 8.0 mmol/l were randomly assigned, in a 2:1 ratio, to receive either fluvastatin 40 mg od (n=52) or matching placebo (n=27). Changes in total cholesterol (TC) in the fluvastatin and placebo groups were -17.0% and +4.5%, respectively, (p<0.001); the corresponding changes in LDL were -20.5% and +4.8% (P<0.001) and in triglycerides -14.5% and +7.1% (p=0.012) at the end of the 1-year study period. Withdrawals were more frequent in the fluvastatin group (23% vs. 11% p=0.24). Two deaths occurred during the study (the rate expected from International Society of Heart Lung Transplantation registry) and appeared to be unrelated to the study medication. There were no episodes of rhabdomyolysis or other serious drug-related side effects.

CONCLUSIONS

Fluvastatin (40 mg/day) was both an effective and a safe treatment for hypercholesterolemia in patients who had undergone heart transplantation more than 3 months previously.

Clinical pharmacokinetics of atorvastatin

Hypercholesterolaemia is a risk factor for the development of atherosclerotic disease. Atorvastatin lowers plasma low-density lipoprotein (LDL) cholesterol levels by inhibition of HMG-CoA reductase. The mean dose-response relationship has been shown to be log-linear for atorvastatin, but plasma concentrations of atorvastatin acid and its metabolites do not correlate with LDL-cholesterol reduction at a given dose. The clinical dosage range for atorvastatin is 10-80 mg/day, and it is given in the acid form. Atorvastatin acid is highly soluble and permeable, and the drug is completely absorbed after oral administration. However, atorvastatin acid is subject to extensive first-pass metabolism in the gut wall as well as in the liver, as oral bioavailability is 14%. The volume of distribution of atorvastatin acid is 381L, and plasma protein binding exceeds 98%. Atorvastatin acid is extensively metabolised in both the gut and liver by oxidation, lactonisation and glucuronidation, and the metabolites are eliminated by biliary secretion and direct secretion from blood to the intestine. In vitro, atorvastatin acid is a substrate for P-glycoprotein, organic anion-transporting polypeptide (OATP) C and H+-monocarboxylic acid cotransporter. The total plasma clearance of atorvastatin acid is 625 mL/min and the half-life is about 7 hours. The renal route is of minor importance (<1%) for the elimination of atorvastatin acid. In vivo, cytochrome P450 (CYP) 3A4 is responsible for the formation of two active metabolites from the acid and the lactone forms of atorvastatin. Atorvastatin acid and its metabolites undergo glucuronidation mediated by uridinediphosphoglucuronyltransferases 1A1 and 1A3. Atorvastatin can be given either in the morning or in the evening. Food decreases the absorption rate of atorvastatin acid after oral administration, as indicated by decreased peak concentration and increased time to peak concentration. Women appear to have a slightly lower plasma exposure to atorvastatin for a given dose. Atorvastatin is subject to metabolism by CYP3A4 and cellular membrane transport by OATP C and P-glycoprotein, and drug-drug interactions with potent inhibitors of these systems, such as itraconazole, nelfinavir, ritonavir, cyclosporin, fibrates, erythromycin and grapefruit juice, have been demonstrated. An interaction with gemfibrozil seems to be mediated by inhibition of glucuronidation. A few case studies have reported rhabdomyolysis when the pharmacokinetics of atorvastatin have been affected by interacting drugs. Atorvastatin increases the bioavailability of digoxin, most probably by inhibition of P-glycoprotein, but does not affect the pharmacokinetics of ritonavir, nelfinavir or terfenadine.

Genetic polymorphisms in cytochrome P450 enzymes: effect on efficacy and tolerability of HMG-CoA reductase inhibitors

Adverse drug reactions are common; they are responsible for a number of debilitating side effects and are a significant cause of death following drug therapy. It is now clear that a significant proportion of these adverse drug reactions, as well as therapeutic failures, are caused by genetic polymorphism, genetically based interindividual differences in drug absorption, disposition, metabolism, or excretion. HMG-CoA reductase inhibitors are generally very well tolerated and easy to administer with good patient acceptance. There are only two uncommon but potentially serious adverse effects related to HMG-CoA reductase inhibitor therapy: hepatotoxicity and myopathy. The occurrence of lethal rhabdomyolysis in patients treated with cerivastatin has prompted concern on the part of physicians and patients regarding the tolerability of HMG-CoA reductase inhibitors. Apart from pravastatin and rosuvastatin, HMG-CoA reductase inhibitors are metabolized by the phase I cytochrome P450 (CYP) superfamily of drug metabolizing enzymes. The best-characterized pharmacogenetic polymorphisms are those within this enzyme family. One of these enzymes, CYP2D6, plays an important role in the metabolism of simvastatin. It has been shown that the cholesterol-lowering effect as well as the efficacy and tolerability of simvastatin is influenced by CYP2D6 genetic polymorphism. Because the different HMG-CoA reductase inhibitors differ, with respect to the degree of metabolism by the different CYP enzymes, genotyping may help to select the appropriate HMG-CoA reductase inhibitor and the optimal dosage during the start of the treatment and will allow for more efficient individual therapy. A detailed knowledge of the genetic basis of individual drug response is potentially of major clinical and economic importance.

Tacrolimus and cerivastatin pharmacokinetics and adverse effects after single and multiple dosing with cerivastatin in renal transplant recipients

AIMS

In contrast to cyclosporin, only limited information exists on the interaction potential between the immunosuppressive agent tacrolimus and HMG-CoA reductase inhibitors, which are metabolized via the cytochrome P450 system. The aim of this study was to investigate the pharmacokinetics, and adverse effects of cerivastatin combined with tacrolimus in renal transplant patients.

METHODS

Ten patients with stable kidney graft functions and LDL-cholesterol serum concentrations > 110 mg dl-1 were included in the study. After an observation period of 3 months, cerivastatin (0.2 mg daily) was administered for an additional 3 months. Tacrolimus steady-state pharmacokinetics and cerivastatin single- and multiple-dose pharmacokinetics were determined. Lipid concentrations, routine laboratory parameters and adverse events were obtained and analysed throughout the study period of 6 months.

RESULTS

Blood tacrolimus trough concentrations were not affected by cerivastatin (mean +/- SD 8.6 +/- 2.1 ng ml(-1) before, and 8.7 +/- 2.4 ng ml(-1) at day 90 of cerivastatin dosing, with a 95% confidence interval on the difference = 0.97, 1.08). The mean area under the blood concentration-time curve to 24 h (AUC(0,24 h)) for cerivastatin was 14.5 +/- 2.53 micro g l(-1) h(-1) at day 1 after starting treatment and 19.02 +/- 3.55 micro g l(-1) h(-1) (3 months later), resulting in a 35% higher (AUC(0,24 h)) compared with the first dose. Total cholesterol, LDL-cholesterol and triglyceride concentrations were significantly lowered by cerivastatin whereas no significant effect of cerivastatin on serum creatininkinase concentrations was observed and no adverse effects were documented.

CONCLUSIONS

Tacrolimus increased the AUC(0, 24 h) of cerivastatin by a mean of 35% in renal transplant patients. Cerivastatin had no detectable effect on the pharmacokinetics of tacrolimus.

Elimination of alfentanil delivered by infusion is not altered by the chronic administration of atorvastatin

BACKGROUND AND OBJECTIVE

Statins are prescribed for patients with hypercholesterolemia. Atorvastatin is metabolized by cytochrome P4503A4 and inhibits P4503A4 activity in vitro. Alfentanil is a potent opioid used in clinical anaesthetic practice and is also metabolized by P4503A4. This study tested the hypothesis that chronic atorvastatin administration inhibits the metabolism of alfentanil.

METHODS

Sixteen patients undergoing elective surgery were studied as matched pairs. One member of each pair was maintained on standard doses of atorvastatin for at least 4 months. Each patient received an alfentanil bolus (80 microg kg(-1)) intravenously (i.v.), followed by an alfentanil infusion (0.67 microg kg(-1) min(-1)) for 90 min. Serial plasma alfentanil concentrations were measured using gas chromatography-nitrogen phosphorous detection. Pharmacokinetic parameters were calculated using two-compartment linear modelling.

RESULTS

One patient and the corresponding match were excluded from the analysis. The elimination half-life of alfentanil was similar in the control and atorvastatin groups (98.8 +/- 12.4 versus 98.3 +/- 11.3 min, respectively). The clearance (Cl), volume of distribution at steady-state (Vdss) and area under the curve (AUC) were similar in the two groups (Cl = 0.20 (+/- 0.06) and 0.22 (+/- 0.04) L min(-1), Vdss = 0.38 (+/- 0.07) and 0.39 (+/- 0.07) L kg(-1), AUC = 0.05 (+/- 0.02) and 0.04 (+/- 0.01) mg min mL(-1)).

CONCLUSIONS

Concurrent atorvastatin administration does not alter the pharmacokinetics of alfentanil in patients undergoing elective surgery.

Aggressive lipid management for cardiovascular prevention: evidence from clinical trials

Epidemiologic evidence shows that elevated serum cholesterol, specifically low-density lipoprotein cholesterol (LDL-C), increases the risk of coronary heart disease (CHD). Moreover, large-scale intervention trials demonstrate that treatment with HMG-CoA reductase inhibitors (statins), the most effective drug class for lowering LDL-C, significantly reduces the risk of CHD events. Unfortunately, only a moderate percentage of hypercholesterolemic patients are achieving LDL-C targets specified by the National Cholesterol Education Program (NCEP), in part because clinicians are not effectively titrating medications as needed to achieve LDL-C goals. Recent evidence suggests that more aggressive LDL-C lowering may provide greater clinical benefit, even in individuals with moderately elevated serum cholesterol levels. Furthermore, recent studies suggest that statins have cardioprotective effects in many high-risk individuals, including those with baseline LDL-C <100 mg/dl. High-density lipoprotein cholesterol (HDL-C) was recognized by the NCEP-Adult Treatment Panel II (ATP II) as a negative risk factor for CHD. The NCEP-ATP III guidelines have also reaffirmed the importance of HDL-C by increasing the low HDL-C designation from <35 to <40 mg/dl as a major risk factor for CHD. Similarly, triglyceride control will play a larger role in dyslipidemia management. As more clinicians effectively treat adverse lipid and lipoprotein cardiovascular risk factors, patients will likely benefit from reductions in cardiovascular events.

Cytochrome P450 drug interactions within the HMG-CoA reductase inhibitor class: are they clinically relevant?

The present review outlines the clinical relevance of pharmacokinetic drug interactions within the HMG-CoA reductase inhibitor class. These interactions can result in markedly increased or decreased plasma concentrations of some drugs within this class. However, the relationship between altered plasma concentrations and adverse effects or toxicity may not be linear. It is likely that other variables affect this concentration-effect relationship including: rapid changes in the concentration, concomitant lipid-lowering therapy or host genetic factors that code for different forms or amounts of metabolising enzymes and drug receptors. It is not currently possible to predict which patients will manifest clinically important drug-drug interactions, nor what concentration of an HMG-CoA reductase inhibitor will cause rhabdomyolysis. Thus, until prescribers have better scientific information from which to develop a 'therapeutic range' for each agent, caution should be exercised. In particular, patients taking a CYP3A4-metabolised agent, e.g. atorvastatin, simvastatin and lovastatin, should not be started on a CYP3A4 inhibitor or inducer without close monitoring.

Lipid profile before and after renal transplantation--a longitudinal study

BACKGROUND

The data on lipid profile in renal transplant recipients from the Indian subcontinent is scant.

METHODS

Lipid profile was studied in 30 consecutive patients of end stage renal disease before renal transplantation (0 month) and prospectively posttransplantation at 1, 3, and 6 months. The results were compared with 30, age and sex matched, healthy controls. All the patients received triple immunosuppression (prednisolone, azathioprine and cyclosporine).

RESULTS

Pretransplantation, the hypertriglyceridemia and hypercholesterolemia was present in 20% and 7% of the patients and the difference (elevation) in the mean values of various lipid fractions was not significant compared to healthy controls except a fall in HDL (p < .01). After renal transplantation, there was a significant elevation in the mean values of total cholesterol, triglycerides, VLDL, and LDL cholesterol at 1, 3, and 6 months. HDL cholesterol levels remained significantly lower as compared to healthy controls. Although, the mean values of serum triglycerides and cholesterol were significantly higher in diabetic end stage renal disease compared to nondiabetic ESRD, however there was insignificant difference in the lipid profile amongst diabetic and nondiabetic renal allograft recipients.

CONCLUSION

Our data shows distinct elevation in the lipids and lipoproteins after renal transplantation and immunosuppressive drugs seem to be the culprit.

Combination lipid-lowering therapy with statins: safety issues in the postcerivastatin era

Combination lipid-altering regimens represent an emerging clinical paradigm to meet increasingly stringent consensus lipoprotein targets for coronary prevention. This practice, together with escalating prevalences of coronary artery disease in certain ageing (western industrial) populations, polypharmacy in the elderly and the recent voluntary market withdrawal of cerivastatin, warrants a re-examination of the safety profiles of 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase inhibitors (i.e., statins). These agents are exceedingly well-tolerated in the vast majority of patients, very infrequently precipitating musculoskeletal symptoms and/or signs. Statins vary in their pharmacological profiles, leading to distinct levels of systemic exposure and capacities to penetrate skeletal myocytes. Pharmacokinetic interactions with certain agents increase the likelihood of statin-induced myopathy and, in exceedingly rare instances, potentially fatal rhabdomyolysis with myoglobinuria and renal failure. As with other medical decisions, the anticipated benefits of long-term statin therapy, with or without other lipid-altering agents, need to be weighed against the prospects of clinically significant drug interactions. In clinical trials and postmarketing surveillance, the two statins that are not metabolised by the cytochrome P450 3A4 system (fluvastatin and pravastatin) have exhibited very low propensities to elicit myopathy when combined with other agents. These agents should be considered initially when contemplating combination lipid-lowering regimens for coronary prevention.

Fluvastatin-induced rhabdomyolysis

OBJECTIVE

To demonstrate a case of rhabdomyolysis with acute renal failure in a patient receiving fluvastatin and to present evidence that this was an adverse drug reaction to fluvastatin.

CASE SUMMARY

A 51-year-old white man with a past medical history significant for hyperlipidemia treated with fluvastatin presented with malaise, myalgias, nausea, and lumbar back pain. The patient had azotemia with elevated creatine kinase (CK), lactate dehydrogenase, and transaminases. He developed hematuria and proteinuria. Laboratory results demonstrated a normal antinuclear antibody, rheumatoid factor, angiotensin-converting enzyme, antineutrophil cytoplasmic antibody, and thyroid-stimulating hormone. Cytomegalovirus and Epstein-Barr virus titers were negative for recent infection. There were no signs of systemic infection; the white blood cell count was normal and blood and urine cultures were negative. Renal ultrasound showed hyperechoic renal cortices with no obstruction. The discontinuation of fluvastatin and hemodialysis led to a rapid decrease in CK and improvement in symptoms.

DISCUSSION

Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have the potential to cause rhabdomyolysis. However, fluvastatin is rarely associated with rhabdomyolysis when compared to other statins. Differences in biochemical and pharmacokinetic properties between fluvastatin and other HMG-CoA reductase inhibitors may be important in the development of rhabdomyolysis.

CONCLUSIONS

Fluvastatin was the precipitating factor causing rhabdomyolysis in this case report. This patient had no other findings to suggest infection or other disorder inducing rhabdomyolysis. An objective causality assessment revealed that the adverse drug reaction was probable as determined by the Naranjo probability scale. Fluvastatin has the potential to cause serious adverse effects. Therefore, a heightened awareness by the patient and physician for potential signs of myopathy is recommended.

Fluvastatin

Fluvastatin was the first wholly synthetic statin to the market and is effective in reducing total and low density lipoprotein cholesterol, which translates into reductions in coronary heart disease events. The Lescol Intervention Prevention Study has established the effectiveness of the early use of statins in reducing recurrent events in high-risk patients with coronary heart disease post percutaneous coronary interventions. Fluvastatin is well-tolerated with few side effects. The occurrence of significant abnormalities in liver enzymes is infrequent, and the risk of myositis and rhabdomyolysis seems to be less than with other statins. There have been no reports of fatal rhabdomyolysis to date. The potential for drug interactions with fluvastatin is low. It seems safe in combination with cyclosporin and there have been few reports of rhabdomyolysis when using fluvastatin in combination with other lipid-lowering agents. It is nevertheless important to be vigilant for this potentially important side effect and, as with other statins, inform patients of the potential risk and suggestive symptoms. Fluvastatin provides a useful option in treating hypercholesterolaemia in patients at high risk of coronary heart disease.

Rhabdomyolysis due to red yeast rice (Monascus purpureus) in a renal transplant recipient

Rhabdomyolysis is a known complication of hepatic 3-methylglutaryl coenzyme A reductase (HMG-CoA) inhibitor (statin) therapy for posttransplant hyperlipidemia, and thus monitoring for this effect is indicated. We report a case of an herbal preparation-induced rhabdomyolysis in a stable renal-transplant recipient, attributed to the presence of red yeast rice (Monascus purpureus) within the mixture. The condition resolved when consumption of the product ceased. Rice fermented with red yeast contains several types of mevinic acids, including monacolin K, which is identical to lovastatin. We postulate that the interaction of cyclosporine and these compounds through the cytochrome P450 system resulted in the adverse effect seen in this patient. Transplant recipients must be cautioned against using herbal preparations to lower their lipid levels to prevent such complications from occurring.

Pharmacokinetic-pharmacodynamic drug interactions with HMG-CoA reductase inhibitors

The HMG-CoA reductase inhibitors (statins) are effective in both the primary and secondary prevention of ischaemic heart disease. As a group, these drugs are well tolerated apart from two uncommon but potentially serious adverse effects: elevation of liver enzymes and skeletal muscle abnormalities, which range from benign myalgias to life-threatening rhabdomyolysis. Adverse effects with statins are frequently associated with drug interactions because of their long-term use in older patients who are likely to be exposed to polypharmacy. The recent withdrawal of cerivastatin as a result of deaths from rhabdomyolysis illustrates the clinical importance of such interactions. Drug interactions involving the statins may have either a pharmacodynamic or pharmacokinetic basis, or both. As these drugs are highly extracted by the liver, displacement interactions are of limited importance. The cytochrome P450 (CYP) enzyme system plays an important part in the metabolism of the statins, leading to clinically relevant interactions with other agents, particularly cyclosporin, erythromycin, itraconazole, ketoconazole and HIV protease inhibitors, that are also metabolised by this enzyme system. An additional complicating feature is that individual statins are metabolised to differing degrees, in some cases producing active metabolites. The CYP3A family metabolises lovastatin, simvastatin, atorvastatin and cerivastatin, whereas CYP2C9 metabolises fluvastatin. Cerivastatin is also metabolised by CYP2C8. Pravastatin is not significantly metabolised by the CYP system. In addition, the statins are substrates for P-glycoprotein, a drug transporter present in the small intestine that may influence their oral bioavailability. In clinical practice, the risk of a serious interaction causing myopathy is enhanced when statin metabolism is markedly inhibited. Thus, rhabdomyolysis has occurred following the coadministration of cyclosporin, a potent CYP3A4 and P-glycoprotein inhibitor, and lovastatin. Itraconazole has been shown to increase exposure to simvastatin and its active metabolite by at least 10-fold. Pharmacodynamically, there is an increased risk of myopathy when statins are coprescribed with fibrates or nicotinic acid. This occurs relatively infrequently, but is particularly associated with the combination of cerivastatin and gemfibrozil. Statins may also alter the concentrations of other drugs, such as warfarin or digoxin, leading to alterations in effect or a requirement for clinical monitoring. Knowledge of the pharmacokinetic properties of the statins should allow the avoidance of the majority of drug interactions. If concurrent therapy with known inhibitors of statin metabolism is necessary, the patient should be monitored for signs and symptoms of myopathy or rhabdomyolysis and the statin should be discontinued if necessary.

Rhabdomyolysis after concomitant use of cyclosporine, simvastatin, gemfibrozil, and itraconazole

OBJECTIVE

To report a case of rhabdomyolysis in a patient receiving cyclosporine, simvastatin, gemfibrozil, and itraconazole.

CASE REPORT

Rhabdomyolysis occurring in transplant patients receiving both cyclosporine and the hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor lovastatin has been well documented. The exact mechanism by which this interaction leads to rhabdomyolysis is unknown. Experience with newer agents of the statin drug class in transplant patients is limited. Since the interaction between cyclosporine and HMG-CoA reductase inhibitors involves the CYP3A4 enzyme system, the possibility of amplifying this interaction exists when other drugs affecting the same enzyme system are coprescribed. We describe a case in which a heart transplant recipient stable on a drug regimen that included cyclosporine, simvastatin, and gemfibrozil developed rhabdomyolysis after initiation of the antifungal agent itraconazole.

DISCUSSION

Drug-drug interactions due to shared metabolism via the CYP3A4 pathway can result in significant adverse outcomes. This article discusses concurrent use of an HMG-CoA reductase inhibitor with other drugs that inhibit the CYP3A4 isoenzyme, leading to a case of possible fatal rhabdomyolysis.

CONCLUSIONS

Clinicians must be aware of drugs metabolized via cytochrome P450 isoenzymes and identify those requiring risk-versus-benefit analysis before prescribing. Patients need to be educated as to signs and symptoms requiring immediate physician intervention.

Atorvastatin: an updated review of its pharmacological properties and use in dyslipidaemia

Atorvastatin is a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. In dosages of 10 to 80 mg/day, atorvastatin reduces levels of total cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride and very low-density lipoprotein (VLDL)-cholesterol and increases high-density lipoprotein (HDL)-cholesterol in patients with a wide variety of dyslipidaemias. In large long-term trials in patients with primary hypercholesterolaemia. atorvastatin produced greater reductions in total cholesterol. LDL-cholesterol and triglyceride levels than other HMG-CoA reductase inhibitors. In patients with coronary heart disease (CHD), atorvastatin was more efficacious than lovastatin, pravastatin. fluvastatin and simvastatin in achieving target LDL-cholesterol levels and, in high doses, produced very low LDL-cholesterol levels. Aggressive reduction of serum LDL-cholesterol to 1.9 mmol/L with atorvastatin 80 mg/day for 16 weeks in patients with acute coronary syndromes significantly reduced the incidence of the combined primary end-point events and the secondary end-point of recurrent ischaemic events requiring rehospitalisation in the large. well-designed MIRACL trial. In the AVERT trial, aggressive lipid-lowering therapy with atorvastatin 80 mg/ day for 18 months was at least as effective as coronary angioplasty and usual care in reducing the incidence of ischaemic events in low-risk patients with stable CHD. Long-term studies are currently investigating the effects of atorvastatin on serious cardiac events and mortality in patients with CHD. Pharmacoeconomic studies have shown lipid-lowering with atorvastatin to be cost effective in patients with CHD, men with at least one risk factor for CHD and women with multiple risk factors for CHD. In available studies atorvastatin was more cost effective than most other HMG-CoA reductase inhibitors in achieving target LDL-cholesterol levels. Atorvastatin is well tolerated and adverse events are usually mild and transient. The tolerability profile of atorvastatin is similar to that of other available HMG-CoA reductase inhibitors and to placebo. Elevations of liver transaminases and creatine phosphokinase are infrequent. There have been rare case reports of rhabdomyolysis occurring with concomitant use of atorvastatin and other drugs.

CONCLUSION

Atorvastatin is an appropriate first-line lipid-lowering therapy in numerous groups of patients at low to high risk of CHD. Additionally it has a definite role in treating patients requiring greater decreases in LDL-cholesterol levels. Long-term studies are under way to determine whether achieving very low LDL-cholesterol levels with atorvastatin is likely to show additional benefits on morbidity and mortality in patients with CHD.