Rhabdomyolysis associated with simvastatin-gemfibrozil therapy

Drug-drug interactions in cardiovascular catheterizations and interventions

Patients presenting for invasive cardiovascular procedures are frequently taking a variety of medications aimed to treat risk factors related to heart and vascular disease. During the procedure, antithrombotic, sedative, and analgesic medications are commonly needed, and after interventional procedures, new medications are often added for primary and secondary prevention of ischemic events. In addition to these prescribed medications, the use of over-the-counter drugs and supplements continues to rise. Most elderly patients, for example, are taking 5 or more prescribed medications and 1 or more supplements, and they often have some degree of renal insufficiency. This polypharmacy might result in drug-drug interactions that affect the balance of thrombotic and bleeding events during the procedure and during long-term treatment. Mixing of anticoagulants, for instance, might lead to periprocedural bleeding, and this is associated with an increase in long-term adverse events. Furthermore, the range of possible interactions with thienopyridine antiplatelets is of concern, because these drugs are essential to immediate and extended interventional success. The practical challenges in the field are great-some drug-drug interactions are likely present yet not well understood due to limited assays, whereas other interactions have well-described biological effects but seem to be more theoretical, because there is little to no clinical impact. Interventional providers need to be attentive to the potential for drug-drug interaction, the associated harm, and the appropriate action, if any, to minimize the potential for medication-related adverse events. This review will focus on drug-drug interactions that have the potential to affect procedural success, either through increases in immediate complications or compromising longer-term outcome.

Gemfibrozil-Induced Myositis in a Patient with Normal Renal Function

OBJECTIVE

To describe a case of gemfibrozil monotherapy-induced myositis in a patient with normal renal function

CASE SUMMARY

A 68-year-old white man presented to his primary care clinic complaining of a 6-month history of total body pain. His past medical history was significant for hypertension, diabetes mellitus, hyperlipidemia, gastroesophageal reflux disease, benign prostatic hypertrophy, arthritis, impotence, and pancreatic cancer that required excision of part of his pancreas. His home drug regimen included bupropion 75 mg twice daily, gemfibrozil 600 mg twice daily for the past 8 months, glimiperide 1 mg daily, insulin glargine 5 units at bedtime, insulin aspart 5 units in the evening, lisinopril 10 mg daily, omeprazole 40 mg daily, pregabalin 100 mg daily, and sildenafil 100 mg as needed. Laboratory test results were significant for elevated aspartate aminotransferase (AST) 78 U/L (reference range 15–46 U/L), alanine aminotransferase (ALT) 83 U/L (13–69 U/L), and creatine kinase (CK) 3495 U/L (55–170 U/L). Serum creatinine was normal at 1.19 mg/dL. The physician determined that the elevated CK indicated myositis secondary to gemfibrozil use, and gemfibrozil was subsequently discontinued. The patient returned 1 week later to repeat the laboratory tests. Results were CK 220 U/L, AST 26 U/L, ALT 43 U/L, and serum creatinine 1.28 mg/dL. The patient was asked to return in 3 weeks to repeat the laboratory tests. At that time, CK had continued to decrease to 142 U/L, and the AST and ALT had returned to normal, at 22 and 29 U/L, respectively. The patient reported complete resolution of total body pain 3 weeks after discontinuation of gemfibrozil. Follow-up 5 weeks after discontinuation revealed no change compared to the 3-week follow-up.

DISCUSSION

Myositis most often produces weakness and elevated CK levels more than 10 times the upper limit of normal. The risk of developing myositis, myopathy, or rhabdomyolysis is low (1%) when fibrates such as gemfibrozil are used as monotherapy. Evaluation of the literature revealed one case of gemfibrozilrelated myositis in a patient with chronic renal failure. There is also one report of myopathy associated with gemfibrozil monotherapy in a patient with normal renal function. The present case is the first documented case of gemfibrozil monotherapy-induced myositis in a patient with normal renal function. The Naranjo probability scale indicated a probable relationship between gemfibrozil treatment and the onset of myositis in our patient. Other potential causes of myositis were ruled out by patient interview and chart review.

CONCLUSIONS

Although the risk of myositis appears to be low with gemfibrozil monotherapy, clinicians should be aware of the potential for this adverse event. For patients taking gemfibrozil monotherapy who present with myalgia, discontinuation of the medication may be necessary for the alleviation of pain.

Recovery time in a case of gemfibrozil and simvastatin-associated rhabdomyolysis

Simvastatin is a cholesterol-lowering medication heavily prescribed to treat and prevent vascular disease. Despite widespread use, cases of simvastatin-induced rhabdomyolysis are rare. Little information is available regarding the recovery period for a patient who has experienced drug-induced rhabdomyolysis. We present a case involving a patient with multiple risk factors (advanced age, high-dose simvastatin therapy, concomitant nonsteroidal anti-inflammatory medication, and concomitant gemfibrozil therapy) and highlight his recovery course.

[Maximal initial dose of simvastatin causing acute renal failure through rhabdomyolysis: risk factors, pathomechanism and therapy related to a case]

Rhabdomyolysis (RML) is a rare and severe adverse effect of simvastatin (SIM). Several risk factors have been described which play a role in its pathogenesis, namely age >65, diabetes mellitus, renal disease, high-dose statin therapy, chemicals metabolized by cytochrome P450 3A4 or idiosyncrasy.

CASE SUMMARY

A 66-year-old man with diabetes, ischaemic heart disease and hypertension, on medication of CYP3A4 substrates amlodipine and alprazolam, maximal daily dose of SIM has been started for unknown cholesterol level. On the second day dark-brown urine, paraparesis, bile-like vomiting, on his fourth day of treatment total tetraparesis and oliguria characterized RML with acute renal failure. During his hospitalization of one-hundred-six days he underwent fourty-nine dialysis treatments. Sixteen months follow-up after discharge from hospital, his walking improved up to using one stick now. His cholesterol level is in physiological range with no statin therapy.

CONCLUSIONS

On account of risk factors listed above this case should have been administered to low initial dose of SIM. Developing myalgia or weakness in muscles, treatment must be stopped. In a case of predisposition to RML statin therapy and dosage can only be performed under continuous supervision.

Extract of black tea (pu-ehr) inhibits postprandial rise in serum cholesterol in mice, and with long term use reduces serum cholesterol and low density lipoprotein levels and renal fat weight in rats

A water-soluble extract of a traditional Chinese fermented black tea, pu-ehr, decomposes bile acid cholesterol micelles. This black tea extract (BTE) was studied to see if it could decrease the postprandial elevation of blood cholesterol levels after a single administration in ddY mice. It was found that BTE (0.3 g/kg) significantly decreased the postprandial rise in blood cholesterol levels after oral administration of cholesterol (130 mg/kg). A non-fermented tea (i.e. green tea) extract did not prevent the postprandial increase in blood cholesterol. In a subsequent study, 5-week-old Sprague-Dawley (SD) rats were fed BTE for 3 weeks, following which a dose-dependent and significant decrease in serum total cholesterol levels (1.36 mmol/L, 0.1% BTE, p < 0.05) was found and also in renal fat weight (0.3% BTE, p < 0.05). LDL cholesterol levels (0.51 mmol/L, 0.1% BTE, p < 0.05) were also significantly decreased. There were no significant changes in the weights of other organs or in the serum levels of other clinical markers. Thus, BTE has a specific antihypercholesterol effect in rodents, which might potentially aid in the management of hyperlipidaemia in man.

Combination therapy with an HMG-CoA reductase inhibitor and a fibric acid derivative: a critical review of potential benefits and drawbacks

It has been clearly shown that lowering low density lipoprotein-cholesterol (LDL-C) [most often with an HMG-CoA reductase inhibitor] decreases the risk of a cardiovascular event. However, this risk reduction was, at most, 35% in clinical trials, meaning that many events could not be prevented. Moreover, reaching target lipid values as recommended by the current guidelines is often difficult, mainly in high-risk situations such as secondary prevention or type 2 diabetes mellitus. As the two main classes of lipid-lowering drugs (HMG-CoA reductase inhibitors and fibric acid derivatives) have complementary effects on lipid parameters, it seems logical to combine both treatments particularly in patients with combined hyperlipidemia. In fact, combination therapy with an HMG-CoA reductase inhibitor and a fibric acid derivative induces a further decrease in LDL-C levels compared with monotherapy and improves other lipid values such as high density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) levels. Unfortunately, there are currently no available randomized, prospective clinical data on the reduction of the incidence of cardiovascular events with such a combination. This is mainly because the use of HMG-CoA reductase inhibitor and fibric acid derivative combinations was initially described as dangerous. It is true that such a combination increases the risk of muscle toxicity that already exists with monotherapy. Muscle toxicity can eventually lead to life-threatening rhabdomyolysis and some precautions of use are required; however, the risk seems actually lower than what has been initially reported. The use of combined therapy with an HMG-CoA reductase inhibitor and a fibric acid derivative requires the respect of some rules such as avoiding the prescription in patients with concomitant conditions like renal failure and avoiding the use of gemfibrozil as a fibric acid derivative in such a combination. It is now imperative to design clinical trials to determine the clinical efficacy and precise safety of this combined treatment especially in patients with abnormalities in every parameter of the lipid triad (LDL, HDL and TG) and a high vascular risk such as patients with type 2 diabetes mellitus.

Atorvastatin monotherapy vs. combination therapy in the management of patients with combined hyperlipidemia

BACKGROUND

Mixed hyperlipidemia is a common disorder characterized by elevated VLDL and LDL levels. Patients with this syndrome usually are in need of combination therapy, comprising a fibric acid derivate with a statin drug in order to achieve LDL and triglyceride target values. Atorvastatin is a hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor demonstrated to be effective in reducing both cholesterol (CHOL) and triglyceride (TG) levels in humans. We examined the efficacy of atorvastatin as monotherapy in achieving a better or the same lipid profile in patients with mixed hyperlipidemia treated with combination therapy.

DESIGN

We compared atorvastatin with a combination of a fibric acid derivate and a statin drug (other than atorvastatin) in a 24-week, prospective randomized, open-label study of 27 patients with mixed hyperlipidemia.

METHODS

All 27 patients had been treated with statin-fibrate therapy in different regimens for at least a year. Atorvastatin at a daily dose of 20 mg was substituted for statin-fibrate therapy. Lipid and safety profiles were assessed.

RESULTS

Atorvastatin significantly reduced total cholesterol, LDL-C, and HDL-C compared to statin-fibrate therapy. In contrast, TG and glucose levels were significantly elevated with atorvastatin. Target LDL-C and TG was achieved in 10 patients with the single therapy of atorvastatin vs. 6 patients under statin-fibrate. In 16 patients, atorvastatin was at least as effective as, or better than, the combination therapy, and was recommended for continuation of treatment.

CONCLUSION

Atorvastatin is an adequate monotherapy for many mixed hyperlipidemia patients. We recommend atorvastatin be considered for every patient suffering from mixed hyperlipidemia.

Statin adverse effects : a review of the literature and evidence for a mitochondrial mechanism

HMG-CoA reductase inhibitors (statins) are a widely used class of drug, and like all medications, have potential for adverse effects (AEs). Here we review the statin AE literature, first focusing on muscle AEs as the most reported problem both in the literature and by patients. Evidence regarding the statin muscle AE mechanism, dose effect, drug interactions, and genetic predisposition is examined. We hypothesize, and provide evidence, that the demonstrated mitochondrial mechanisms for muscle AEs have implications to other nonmuscle AEs in patients treated with statins. In meta-analyses of randomized controlled trials (RCTs), muscle AEs are more frequent with statins than with placebo. A number of manifestations of muscle AEs have been reported, with rhabdomyolysis the most feared. AEs are dose dependent, and risk is amplified by drug interactions that functionally increase statin potency, often through inhibition of the cytochrome P450 3A4 system. An array of additional risk factors for statin AEs are those that amplify (or reflect) mitochondrial or metabolic vulnerability, such as metabolic syndrome factors, thyroid disease, and genetic mutations linked to mitochondrial dysfunction. Converging evidence supports a mitochondrial foundation for muscle AEs associated with statins, and both theoretical and empirical considerations suggest that mitochondrial dysfunction may also underlie many nonmuscle statin AEs. Evidence from RCTs and studies of other designs indicates existence of additional statin-associated AEs, such as cognitive loss, neuropathy, pancreatic and hepatic dysfunction, and sexual dysfunction. Physician awareness of statin AEs is reportedly low even for the AEs most widely reported by patients. Awareness and vigilance for AEs should be maintained to enable informed treatment decisions, treatment modification if appropriate, improved quality of patient care, and reduced patient morbidity.

Postprandial lipemia: an under-recognized atherogenic factor in patients with diabetes mellitus

Atherosclerotic disease is the leading cause of both morbidity and mortality in patients with type 2 diabetes. In these patients, postprandial dyslipidemia include not only quantitative but also qualitative abnormalities of lipoproteins which are potentially atherogenic and seems to be a significant risk factor for cardiovascular disease since there is evidence that it results in endothelial dysfunction and enhanced oxidative stress. The most common pattern of postprandial dyslipidemia in diabetes consists of high concentrations of triglycerides, higher VLDLs production by the liver and a decrease in their clearance, a predominance of small dense LDL particles, and reduced levels of HDL. The cause of this postprandial dyslipidemia in diabetes is complex and involves a variety of factors including hyperinsulinemia, insulin resistance, hyperglycemia and disturbed fatty acid metabolism. Numerous clinical studies have shown that postprandial dyslipidemia is associated with endothelial dysfunction in type 2 diabetes and with alterations in other surrogate markers in the cascade of atherosclerosis. Current published guidelines indicate that in diabetics the primary lipid target is LDL<100 mg/dL (70 mg/dL in very high-risk patients) and the most appropriate class of drugs are statins although the issue of postprandial dyslipidemia has not been specifically addressed so far. Moreover, several other classes of medications (fibrates, niacin and antidiabetic drugs) as well as non-pharmacological interventions (i.e. diet, smoking cessation and exercise) can be used to treat lipid and lipoprotein abnormalities associated with insulin resistance and type 2 diabetes. These type of interventions may be more appropriate to ameliorate postprandial dyslipidemia. However, this remains to be confirmed on clinical grounds.

A Comparison of Adverse Effects of Simvastatin plus Gemfibrozil and Atorvastatin plus Gemfibrozil

Background

The manufacturer of simvastatin recommends a dose limitation of 10 mg daily when used in combination with gemfibrozil, due to increased risk of myopathy and rhabdomyolysis. Little information is available regarding the risk of adverse effects of atorvastatin when used in combination with gemfibrozil.

Purpose

To compare the rate of discontinuation or dose reduction due to adverse effects with simvastatin and gemfibrozil versus atorvastatin and gemfibrozil.

Methods

Retrospective review of patients taking gemfibrozil in combination with simvastatin 10 mg, simvastatin 80 mg, or atorvastatin 40 mg for at least 6 months.

Results

A total of 166 patients were included; 59 were taking simvastatin 10 mg (S10), 47 were taking simvastatin 80 mg (S80), and 60 were taking atorvastatin 40 mg (A40). There was no significant difference in the rate of discontinuation or dose reduction due to adverse effects among the groups (10.2% for S10, 21.2% for S80, and 10% for A40, P = 0.159). A paired comparison of discontinuation or dose reduction due to adverse effects between the simvastatin 80 mg and atorvastatin 40 mg groups approached a trend toward a difference ( P = 0.104). Severe adverse effects occurred in the simvastatin 80 mg and atorvastatin 40 mg groups.

Conclusion

Our results did not show a significant difference in discontinuation or dose reduction due to adverse effects between patient groups taking gemfibrozil in combination with simvastatin 10 mg, simvastatin 80 mg, or atorvastatin 40 mg. However, the rate of this outcome in the S80 group was approximately double that for the S10 and A40 groups. Further studies are needed to compare the safety of these statin-gemfibrozil combinations.

Safety considerations with fibrate therapy

Fibrates are an important class of drugs for the management of dyslipidemia. This class of drugs is generally well tolerated but is infrequently associated with several safety issues. Fibrates, most likely by an effect mediated by peroxisome proliferator-activated receptor-alpha, may reversibly increase creatinine and homocysteine but are not associated with an increased risk for renal failure in clinical trials. Fibrates are associated with a slightly increased risk (<1.0%) for myopathy, cholelithiasis, and venous thrombosis. In clinical trials, patients without elevated triglycerides and/or low high-density lipoprotein cholesterol (HDL) levels, fibrates are associated with an increase in noncardiovascular mortality. In combination with statins, gemfibrozil generally should be avoided. The preferred option is fenofibrate, which is not associated with an inhibition of statin metabolism. Clinicians are advised to measure serum creatinine before fibrate use and adjust the dose accordingly for renal impairment. Routine monitoring of creatinine is not required, but if a patient has a clinically important increase in creatinine, and other potential causes of creatinine increase have been excluded, consideration should be given to discontinuing fibrate therapy or reducing the dose.

Polymyositis evolving after rhabdomyolysis associated with HMG-CoA reductase inhibitors: a report of two cases

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are commonly used for treatment of hyperlipidemia and its deleterious effects. Myotoxicity has been associated with use of these agents. We report two cases of inflammatory myopathy in patients receiving these agents that did not respond to drug withdrawal and required immunosuppressive treatment. One of these patients developed an antibody to histidyl tRNA synthetase or Jo-1, an autoantibody associated with idiopathic inflammatory myopathies. We suggest that HMG-CoA reductase inhibitor-associated myotoxicity may trigger an immune-mediated inflammatory myopathy. Patients whose muscle abnormalities do not resolve with drug withdrawal should be considered for muscle biopsy.

Management of dyslipidemia in diabetes

Diabetes is associated with a high risk of cardiovascular disease. The management of dyslipidemia, a well-recognized and modifiable risk factor among patients with type 2 diabetes, is an important element in the multifactorial approach to prevent coronary heart disease. Diabetic dyslipidemia typically consists of elevated triglyceride, low high-density lipoprotein cholesterol (HDL-C), and the predominance of small dense low-density lipoprotein (LDL) particles. LDL cholesterol (LDL-C) levels in patients with diabetes are similar to those found in the rest of the population. During the past few years, clinical trials have provided evidence that lipid-lowering therapy has a similar beneficial effect on cardiovascular outcomes in diabetic and nondiabetic individuals. According to current guidelines, the primary lipid target is an LDL-C <100 mg/dL (<70 mg/dL in very high-risk patients) and, to this end, statins are the agents of choice. The appropriate management of dyslipidemia in patients with diabetes, particularly in individuals with low LDL-C, remains controversial. To achieve lipid targets, attention should be directed first toward nonpharmacologic therapeutic interventions to control dyslipidemia, such as diet, exercise, smoking cessation, weight loss, and glycemic control. Statin therapy is recommended for most subjects but, frequently, a combination of lipid-lowering agents is required. A number of combinations are possible, and several factors should be considered to improve the safety of this strategy.

Management of diabetic dyslipidemia

Identification and management of dyslipidemia is an important element in the multi-factorial approach to prevent coronary heart disease. Diabetic dyslipidemia typically consists of elevated triglyceride, low high-density lipoprotein cholesterol, predominance of small, dense low-density lipoprotein (LDL) particles, and average LDL cholesterol (LDL-C). Lipid-lowering therapy has a beneficial effect on cardiovascular outcomes. Statin treatment is beneficial in patients who are older than 40 years of age, irrespective of the LDL-C value. To achieve lipid targets, attention should be directed first toward nonpharmacologic therapeutic interventions, such as diet, exercise, smoking cessation, weight loss, and improving glycemic control. Although statin therapy is recommended for most subjects, judicious use of combination therapy should be considered in the highest risk subjects.

The influence of statin characteristics on their safety and tolerability

The efficacy of the statins for both primary and secondary prevention has now been clearly established in patients across the spectrum of cardiovascular risk. In addition to their primary effect in reducing plasma cholesterol, the statins possess various 'pleiotropic' effects that may contribute to their clinical effectiveness in reducing cardiovascular events, e.g. improvement of endothelial function, reduction of low-density lipoprotein-cholesterol oxidation and stabilisation of atheromatous plaques. Although statins share similar chemical characteristics, they differ significantly in terms of their molecular synthesis, solubility and pharmacokinetic behaviour and metabolism. Side-effects secondary to longterm statin therapy are rare, but rhabdomyolysis may occur when statins are administered together with other drugs that have a direct toxic effect on muscle or which inhibit statin metabolism. Among the various statins, it would appear that fluvastatin has the lowest propensity to interact with other drugs and the least potential to induce myotoxicity.

Strategies for minimizing hyperlipidemia after cardiac transplantation

Allograft coronary artery disease represents a major limitation to long-term survival after cardiac transplantation. Hyperlipidemias have been linked to the development of native coronary atherosclerosis, and hyperlipidemic states have correlated with the severity of allograft coronary artery disease. Heart transplant recipients typically manifest increases in plasma levels of total cholesterol, low-density lipoprotein-cholesterol (LDL-C), and triglycerides within the first 3-12 months following transplantation. Factors known to promote post-transplant hyperlipidemia include the use of corticosteroids, cyclosporine (interference with clearance and increased oxidizability of LDL), sirolimus (hypertriglyceridemia), and patient-specific causes of hyperlipidemia which contributed to their underlying heart disease. Hydroxymethylglutaryl coenzyme-A (HMG-CoA) reductase inhibitors are the foundation of antilipid therapy following cardiac transplantation. Pravastatin is effective in lowering plasma cholesterol levels and is associated with a decreased incidence and progression of allograft coronary artery disease. All HMG-CoA reductase inhibitors except pravastatin are metabolized by the hepatic cytochrome P450 system which metabolizes cyclosporine, increasing the risk of myostitis when they are used in large dosages with cyclosporine. Simvastatin, atorvastatin and fluvastatin have been studied in heart transplant recipients. Gemfibrozil has proved effective in transplant recipients when there is isolated marked elevation of plasma triglyceride levels. When hyperlipidemia persists despite therapy, some benefit may result with conversion from cyclosporine to tacrolimus. Although a definitive link between hyperlipidemia and allograft coronary disease has yet to be proven, available evidence points to abnormal lipid metabolism as part of the complex etiologic machinery driving the process of 'chronic rejection'. Consensus exists within the transplant community that a HMG-CoA reductase inhibitor such as pravastatin, should be part of the routine post-transplant drug regimen, and persistent hyperlipidemia should be aggressively treated.

Dermatomyositis-like syndrome and HMG-CoA reductase inhibitor (statin) intake

A patient developed an adult-onset dermatomyositis-like syndrome characterized by skin rash and progressive proximal muscle weakness concurrent with the intake of simvastatin. Despite discontinuation of the statin, symptoms progressed and required conventional steroid therapy for remission. The association between statins and the development of a musculocutaneous syndrome closely resembling dermatomyositis in susceptible subjects is poorly understood and has been reported rarely. The purpose of this report is to provide additional support for this pathological association. Since the population receiving statins is large and rapidly growing, caregivers are urged to be alert regarding the early recognition and proper care of the spectrum of neuromuscular complications linked to statin intake.

Effectiveness of Statin-Gemfibrozil Combination Therapy in Patients With Mixed Hyperlipidemia: Experience of a Community Lipid Clinic and Safety Review From the Literature

This retrospective study was carried out to assess the effectiveness of statin-gemfibrozil combination therapy in a community practice lipid clinic and to review safety data from published literature. Forty-six consecutive patients received a statin and gemfibrozil combination for resistant hyperlipidemia to either agent therapy. Fasting total cholesterol (mg/dL), high-density lipoprotein cholesterol (mg/dL), and triglycerides (mg/dL) were measured. Low-density lipoprotein cholesterol (mg/dL) was calculated using the Friedewald formula if triglycerides were <400 mg/dL. Combination therapy reduced total cholesterol, low-density lipoprotein cholesterol, and triglycerides by 11% (p=0.02), 22% (p=0.049), and 39% (p=0.0002), respectively, and raised high-density lipoprotein cholesterol by 5% (p=0.3). A pooled analysis of 838 patients from the literature on statin-gemfibrozil combination therapy revealed an incidence of myositis and severe myopathy of 0.7% and 0.6%, respectively (excluding cerivastatin). We conclude that statin-gemfibrozil combination therapy is effective in significantly reducing total cholesterol, low-density lipoprotein cholesterol, and triglycerides with a trend toward raising high-density lipoprotein cholesterol in patients with hyperlipidemia resistant to either agent alone. Myositis and severe myopathy are infrequent, but not rare side effects which may be statin-specific regarding the incidence of occurrence.

Approved and future pharmacotherapy for multiple sclerosis

BACKGROUND

Pharmacotherapy for relapsing-remitting multiple sclerosis (MS) advanced with the demonstration that interferon beta and glatiramer acetate improve the clinical course of this disease. Mitoxantrone is the first drug approved by the Food and Drug Administration for treatment of secondary progressive MS. Despite this progress, the agents presently available are only partially effective, are difficult to administer, and may have significant side effects. Several orally administered immunomodulatory agents are presently being evaluated for treatment of MS. One class of drugs, HMG CoA inhibitors (statins), is safe and well-tolerated and could become another mainstay of MS therapy.

REVIEW SUMMARY

This article reviews the clinical evidence for approved MS therapies and discusses their mechanisms of action. Furthermore, the clinical and laboratory data suggesting a potential role for statins in MS therapy are discussed.

CONCLUSIONS

Although treatment with interferon beta, glatiramer acetate, and mitoxantrone, the approved therapies, provide important treatment options for patients with relapsing-remitting MS and secondary progressive MS, the potential benefits of other medications, including statins, should be explored in controlled clinical trials.

Pharmacology of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins), including rosuvastatin and pitavastatin

Coronary heart disease (CHD) is the leading cause of morbidity and mortality in the Western world, with hypercholesterolemia as the major risk factor. The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors represent the most efficient drugsfor the treatment of hypercholesterolemia. They lower plasma cholesterol due to the inhibition of endogenous cholesterol synthesis in the liverand subsequent increased expression of low-density lipoprotein (LDL) receptors, resulting in an up-regulated catabolic rate for plasma LDL. The beneficial effect of statins on the incidence of CHD was clearly demonstrated in several large-scale clinical trials. Currently, five statins (atorvastatin, fluvastatin, lovastatin, pravastatin, and simvastatin) are available, and two novel compounds (pitavastatin, rosuvastatin) are undergoing clinical investigation. To point out potential mechanisms leading to increased toxicity and to compare the novel statins with the established ones, this article summarizes their pharmacological data since the prevalence of adverse events can be explained at least in part by their pharmacokinetic differences.

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.

How well tolerated are lipid-lowering drugs?

It has been clearly established that lipid-lowering treatments [such as 3-hydroxyl-3-methylglutamyl coenzyme A reductase inhibitors ('statins') or fibrates] can reduce cardiovascular events, and with one of the statins even total mortality, in high-risk populations. Intervention studies have not included the very old, but it is generally assumed that this patient group would benefit from these treatments to an extent similar to younger patients. Worries about the associations seen in observational studies between low cholesterol levels and cancer, cerebral haemorrhage or mood and behaviour change have been largely overcome by findings from the latest large drug intervention trials, which do not show any increase in these conditions with statin or fibrate treatments. The common adverse effects associated with these drugs are relatively mild and often transient in nature. Potentially more serious adverse effects, which are more clearly related to drug treatment and are probably dose-dependent, include elevations in hepatic transaminase levels and myopathy; however, these effects are uncommon and generally resolve rapidly when treatment is stopped. The risk of myopathy with fibrate treatment is increased in patients with renal impairment, and the risk of myopathy with statin treatment increases with co-administration of drugs that inhibit statin metabolism or transport. Other adverse effects are related to specific drugs, for example, clofibrate is associated with an increased risk of gallstones. Studies in elderly patients have not shown an increased risk of adverse effects with lipid-lowering drugs compared with younger patients, but in clinical practice there may be some increased risk, particularly with regards to drug interactions. Therefore, lipid-lowering drugs should be administered with extra caution to elderly patients.

Cerivastatin-induced rhabdomyolysis: 11 case reports

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are a frequently prescribed class of drugs that are generally well tolerated by most patients. A rare, yet serious side effect associated with these drugs is rhabdomyolysis. Although all HMG-CoA reductase inhibitors can cause this adverse effect, prevalence may differ among specific agents. Over a 16-month period, in three hospitals, 11 patients experienced cerivastatin-induced rhabdomyolysis, but no cases of rhabdomyolysis associated with any other HMG-CoA reductase inhibitors were reported.

Pharmacokinetic interactions between protease inhibitors and statins in HIV seronegative volunteers: ACTG Study A5047

OBJECTIVE

Lipid lowering therapy is used increasingly in persons with HIV infection in the absence of safety data or information on drug interactions with antiretroviral agents. The primary objectives of this study were to examine the effects of ritonavir (RTV) plus saquinavir soft-gel (SQVsgc) capsules on the pharmacokinetics of pravastatin, simvastatin, and atorvastatin, and the effect of pravastatin on the pharmacokinetics of nelfinavir (NFV) in order to determine clinically important drug-drug interactions.

DESIGN

Randomized, open-label study in healthy, HIV seronegative adults at AIDS Clinical Trials Units across the USA.

METHODS

Three groups of subjects (arms 1, 2, and 3) received pravastatin, simvastatin or atorvastatin (40 mg daily each) from days 1-4 and 15-18. In these groups, RTV 400 mg and SQVsgc 400 mg twice daily were given from days 4-18. A fourth group (arm 4) received NFV 1250 mg twice daily from days 1-14 with pravastatin 40 mg daily added from days 15-18. Statin and NFV levels were measured by liquid chromatography/tandem mass spectrometry.

RESULTS

Fifty-six subjects completed both pharmacokinetic study days. In arms 1-3, the median estimated area under the curves (AUC)(0-24) for the statins were: pravastatin (arm 1, n = 13), 151 and 75 ng.h/ml on days 4 and 18 (decline of 50% in presence of RTV/SQVsgc), respectively (P = 0.005); simvastatin (arm 2, n = 14), 17 and 548 ng.h/ml on days 4 and 18 (increase of 3059% in the presence of RTV/SQVsgc), respectively (P < 0.001); and total active atorvastatin (arm 3, n = 14), 167 and 289 ng.h/ml on days 4 and 18 (increase of 79% in the presence of RTV/SQVsgc), respectively (P < 0.001). In arm 4, the median estimated AUC(0-8) for NFV (24 319 versus 26 760 ng.h/ml; P = 0.58) and its active M8 metabolite (15 565 versus 14 571 ng.h/m; P = 0.63) were not statistically different from day 14 to day 18 (without or with pravastatin).

CONCLUSIONS

Simvastatin should be avoided and atorvastatin may be used with caution in persons taking RTV and SQVsgc. Dose adjustment of pravastatin may be necessary with concomitant use of RTV and SQVsgc. Pravastatin does not alter the NFV pharmacokinetics, and thus appears to be safe for concomitant use.

Pancreatitis associated with simvastatin plus fenofibrate

OBJECTIVE

To report a case of acute necrotizing pancreatitis associated with simvastatin and fenofibrate use.

CASE SUMMARY

A 70-year-old white man presenting with rapid onset of abdominal pain, nausea, and vomiting was diagnosed with acute pancreatitis. On bowel rest, his condition deteriorated secondary to systemic inflammatory response syndrome, and he was transferred to a tertiary hospital's intensive care unit (ICU). He had been taking fenofibrate for 1 year; 6 months prior to this admission, he had been taking simvastatin 3 days of the week and fenofibrate the other 4 days of the week. The pancreatic tissue became necrotic, requiring surgical debridement. After a hospital stay of 121 days, including multiple ICU admissions, the patient died secondary to a bowel perforation.

DISCUSSION

Although idiopathic pancreatitis cannot be ruled out in this patient, no causes of pancreatitis were identified other than drug induced. Five cases of acute pancreatitis caused by simvastatin have been reported; no case reports were found for fenofibrate. The onset of pancreatitis relative to the duration of therapy with simvastatin supports this medication as a possible cause of the pancreatitis.

CONCLUSIONS

Drug-induced pancreatitis is well established as an adverse effect of some medications, although most are substantiated only with case reports. Given the absence of other apparent causes, simvastatin and fenofibrate should be considered as possible causes of pancreatitis in this patient.

Rhabdomyolysis and HMG-CoA reductase inhibitors

OBJECTIVE

To review rhabdomyolysis and discuss the role of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) and their interactions with other agents in precipitating this condition, and to present case reports of statin-induced rhabdomyolysis.

DATA SOURCE

Relevant clinical literature was accessed using MEDLINE (January 1985-October 2000). The following search terms were used: rhabdomyolysis, adverse events, drug interactions, statins, and HMG-CoA reductase inhibitors.

DISCUSSION

Rhabdomyolysis occurs when extensive muscle damage results in the release of cellular contents into systemic circulation. Major complications include acute renal failure, cardiac abnormalities, and compartment syndrome. Treatment of rhabdomyolysis is supportive, with the primary aim of preventing renal and cardiac complications. Statin monotherapy or combination therapy may result in myopathy, which rarely progresses to rhabdomyolysis. The mechanism for drug interactions with the statins involves their property of lipid or water solubility. This characteristic determines the degree of hepatoenteric or renal metabolism of the statins. All statins except pravastatin undergo metabolism via the cytochrome P450 enzyme system. Other pharmacologic agents that are also metabolized via this pathway may interact with the statins and cause rhabdomyolysis. The risk of statin-induced rhabdomyolysis is increased significantly when statins are used concomitantly with such drugs as fibrates, cyclosporine, macrolide antibiotics, and azole antifungals.

CONCLUSIONS

Rhabdomyolysis is a rare but clinically important adverse event of statin monotherapy or combination therapy. Thorough understanding of this condition may help prevent or minimize adverse health outcomes in patents receiving statin therapy.

Statin-fibrate combination therapy

BACKGROUND

Precautionary warnings for severe myopathy and rhabdomyolysis from the coadministration of statins and fibrates have been well publicized. However, a recent cerivastatin labeling change made the combined use with fibric acid derivatives a contraindication. Practical recommendations for clinicians who care for patients with refractory mixed hyperlipidemia are needed.

OBJECTIVE

To provide recommendations for clinicians in the treatment of refractory mixed hyperlipidemia.

DATA SOURCES

A comprehensive MEDLINE (1966-July 2000) and bibliographic search was performed.

DATA SYNTHESIS

Thirty-six published clinical trials and 29 case reports involving combination therapy with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors and fibric acid derivatives regarding the occurrence of rhabdomyolysis or myopathy were reviewed. The literature review demonstrated that combination therapy with a statin and fibrate increases the risk of muscle damage, with an incidence of 0.12%. Risk factors that predispose patients to myopathy caused by combination statin-fibrate therapy include increased age, female gender, renal or liver disease, diabetes, hypothyroidism, debilitated status, surgery, trauma, excessive alcohol intake, and heavy exercise.

CONCLUSIONS

Combination therapy with a statin and fibrate offers significant therapeutic advantage for the treatment of severe or refractory mixed hyperlipidemia. Although such a combination does increase the risk of myopathy, with an incidence of approximately 0.12%, this small risk of myopathy rarely outweighs the established morbidity and mortality benefits of achieving lipid goals. Nevertheless, a higher incidence of myopathy has been reported with statin monotherapy. When monotherapy with a statin fails to control mixed hyperlipidemia, combination therapy may be considered. Niacin may be added before a fibrate is considered, as it appears to have less risk of myopathy. Statin-fibrate combination therapy must be undertaken cautiously and only after careful risk-benefit analysis. Patient counseling on the risks and warning signs of myopathy is extremely important.

Treatment of the elderly with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors: focus on drug interactions

With the aging of the population, death from coronary heart disease (CHD) and stroke has become more prevalent. Cardiovascular disease (CVD) risk factors, such as hypertension, obesity, and diabetes mellitus increase with age as well. Recent secondary-prevention studies have established the positive effect of statins in decreasing the risk of CHD mortality through the lowering of cholesterol. Statins have an excellent safety record, at least with users under age 65, and provide a cheaper alternative to more costly medical options. The most serious side effect associated with their use is myopathy, which is infrequent. Drug interactions have been found with drugs that compete for the same CYP450 isoenzymes as statins. Several drugs have been shown to significantly inhibit the CYP3A4 pathway; in combination with statins such as lovastatin, simvastatin, atorvastatin, and cerivastatin, they have been shown to elevate serum concentrations of these statins, or may increase the risk of myopathy. Alternatively, other drugs can inhibit the CYP2C9 pathway and may elevate serum concentration of fluvastatin. Due to the number of medications the elderly receive, an understanding of the various metabolic pathways is of vital importance to minimize the potential for drug interactions. The elderly population, while at high risk for CVD, is currently undertreated. Statins can effectively lower low-density lipoprotein cholesterol levels and lessen the risk of CVD for this population.

Implications of cardiovascular risk in patients with type 2 diabetes who have abnormal lipid profiles: is lower enough?

Patients with type 2 diabetes are at high risk for coronary heart disease (CHD); frequently, these patients have abnormal lipid profiles, placing them at even greater risk. A syndrome of insulin resistance, hyperinsulinaemia, hypertension, and high levels of fibrinogen and plasminogen activator inhibitor contributes to cardiovascular risk, which is not sufficiently decreased by glycaemic control alone. In several large interventional trials, CHD risk in patients with diabetes was substantially reduced by aggressive lipid-lowering therapy. In patients with diabetes, CHD, low high-density lipoprotein levels, and normal low-density lipoprotein levels, gemfibrozil reduced fatal and non-fatal CHD events. For lipid-lowering in patients with diabetes and CHD, pravastatin and simvastatin are the only HMG-CoA reductase inhibitors shown to reduce fatal and non-fatal CHD events. Of these, pravastatin has less potential for drug-drug interactions and may be safer to use, particularly for combination therapy with fibric acid derivatives, as may now be important for CHD prevention in mixed dyslipidaemias.

HMG-CoA reductase inhibitors and myotoxicity

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors specifically inhibit HMG-CoA reductase in the liver, thereby inhibiting the biosynthesis of cholesterol. These drugs significantly reduce plasma cholesterol level and long term treatment reduces morbidity and mortality associated with coronary heart disease. The tolerability of these drugs during long term administration is an important issue. Adverse reactions involving skeletal muscle are not uncommon, and sometimes serious adverse reactions involving skeletal muscle such as myopathy and rhabdomyolysis may occur, requiring discontinuation of the drug. Occasionally, arthralgia, alone or in association with myalgia, has been reported. In this article we review scientific data provided via Medline, adverse drug reaction case reports from the Swedish Drug Information System (SWEDIS) and the World Health Organization's International Drug Information System (INTDIS) database, focusing on HMG-CoA reductase inhibitor-related musculoskeletal system events. Cytochrome P450 (CYP) 3A4 is the main isoenzyme involved in the metabolic transformation of HMG-CoA reductase inhibitors. Individuals with both low hepatic and low gastrointestinal tract levels of CYP3A4 expression may be at in increased risk of myotoxicity due to potentially higher HMG-CoA reductase inhibitor plasma concentrations. The reported incidence of myotoxic reactions in patients treated with this drug class varies from 1 to 7% and varies between different agents. The risk of these serious adverse reactions is dose-dependent and may increase when HMG-CoA reductase inhibitors are prescribed concomitantly with drugs that inhibit their metabolism, such as itraconazole, cyclosporin, erythromycin and nefazodone. Electrolyte disturbances, infections, major trauma, hypoxia as well as drugs of abuse may increase the risk of myotoxicity. It is important that the potentially serious adverse reactions are recognised and correctly diagnosed so that the HMG-CoA reductase inhibitor may at once be withdrawn to prevent further muscular damage.

Efficacy and safety of a combination of fluvastatin and bezafibrate in patients with mixed hyperlipidaemia (FACT study)

Preliminary data suggest that fluvastatin may be safely combined with fibrates. The Fluvastatin Alone and in Combination Treatment Study examined the effects on plasma lipids and safety of a combination of fluvastatin and bezafibrate in patients with coronary artery disease and mixed hyperlipidaemia. A total of 333 patients were randomly allocated in this multicentre double-blind trial to receive 40 mg fluvastatin alone (n=80), 400 mg bezafibrate (n=86), 20 mg fluvastatin+400 mg bezafibrate (n=85) or 40 mg fluvastatin+400 mg bezafibrate (n=82) for 24 weeks. Low-density lipoprotein (LDL)-cholesterol decreased >20% in all fluvastatin-containing regimens, with significantly greater decreases compared with bezafibrate alone (P<0.001). Bezafibrate alone and fluvastatin+bezafibrate combinations resulted in greater increases in high-density lipoprotein (HDL)-cholesterol and decreases in triglycerides compared with fluvastatin alone (P<0.001). Fluvastatin (40 mg)+bezafibrate was the most effective for all lipid parameters with a decrease from baseline at endpoint in LDL-cholesterol of 24%, a decrease in triglycerides of 38% and an increase in HDL-cholesterol of 22%. All treatments were well tolerated with no increase in adverse events for combination therapy versus monotherapy, or between combination regimens. No clinically relevant liver (aspartate aminotransferase [ASAT] or alanine aminotransferase [ALAT]) greater than three times the upper limit of normal) or muscular (creatine phosphokinase (CPK) greater than four times the upper limit of normal) laboratory abnormalities were reported. This large study shows 40 mg fluvastatin in combination with 400 mg bezafibrate to be highly effective and superior to either drug given as monotherapy in mixed hyperlipidaemia, and to be safe and well tolerated.

Myoglobinuria

Myoglobinuria refers to an abnormal pathologic state in which an excessive amount of myoglobin is found in the urine, imparting a cola-like hue, usually in association with myonecrosis and a clinical picture of weakness, myalgias, and edema. Myoglobinuria is produced by multiple causes: any condition that accelerates the use or interferes with the availability of oxygen or energy substrates to muscle cells can result in myoglobinuria, as can events that produce direct muscle injury, either mechanical or chemical. Acute renal failure is the most serious complication, which can be prevented by prompt, aggressive treatment. In patients surviving acute attacks, recovery of muscle and renal function is usually complete.

New insights into the pharmacodynamic and pharmacokinetic properties of statins

The beneficial effects of statins are assumed to result from their ability to reduce cholesterol biosynthesis. However, because mevalonic acid is the precursor not only of cholesterol, but also of many nonsteroidal isoprenoid compounds, inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase may result in pleiotropic effects. It has been shown that several statins decrease smooth muscle cell migration and proliferation and that sera from fluvastatin-treated patients interfere with its proliferation. Cholesterol accumulation in macrophages can be inhibited by different statins, while both fluvastatin and simvastatin inhibit secretion of metalloproteinases by human monocyte-derived macrophages. The antiatherosclerotic effects of statins may be achieved by modifying hypercholesterolemia and the arterial wall environment as well. Although statins rarely have severe adverse effects, interactions with other drugs deserve attention. Simvastatin, lovastatin, cerivastatin, and atorvastatin are biotransformed in the liver primarily by cytochrome P450-3A4, and are susceptible to drug interactions when co-administered with potential inhibitors of this enzyme. Indeed, pharmacokinetic interactions (e.g., increased bioavailability), myositis, and rhabdomyolysis have been reported following concurrent use of simvastatin or lovastatin and cyclosporine A, mibefradil, or nefazodone. In contrast, fluvastatin (mainly metabolized by cytochrome P450-2C9) and pravastatin (eliminated by other metabolic routes) are less subject to this interaction. Nevertheless, a 5- to 23-fold increase in pravastatin bioavailability has been reported in the presence of cyclosporine A. In summary, statins may have direct effects on the arterial wall, which may contribute to their antiatherosclerotic actions. Furthermore, some statins may have lower adverse drug interaction potential than others, which is an important determinant of safety during long-term therapy.

Combined hyperlipidemia is associated with increased exercise-induced muscle protein release which is improved by triglyceride-lowering intervention

Although myopathy is considered an adverse effect of treatment with 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors and fibrates in combined hyperlipidemia, the present study was performed to investigate whether combined hyperlipidemia itself is associated with skeletal muscle pathology and whether lipid-lowering intervention has beneficial effects. To investigate whether combined hyperlipidemia is associated with skeletal muscle pathology, 10 male patients and 15 normolipidemic controls underwent a 45-minute standardized bicycle ergometer test at a load of 2 W/kg lean body mass (parallel study). One- and 8-hour postexercise increments in the plasma level of the muscle proteins creatine kinase (CK), myoglobin (Mb), and fatty acid-binding protein (FABP) were assessed as parameters for (subclinical) skeletal muscle pathology. The 8-hour postexercise increments in CK and Mb and 1-hour postexercise increment in Mb were significantly higher in patients than in controls, thus indicating increased exercise-induced muscle membrane permeability in combined hyperlipidemia. To investigate the effects of lipid-lowering intervention on skeletal muscle in combined hyperlipidemia, 21 subjects with combined hyperlipidemia were randomized double-blindly to receive 6 weeks of treatment with fluvastatin 40 mg/d, gemfibrozil 600 mg twice daily, or combination therapy. All subjects underwent an ergometer test before and after treatment. Gemfibrozil treatment alone reduced the CK increments 8 hours postexercise by 47% and the FABP increments 1 and 8 hours postexercise by 83% and 101%, respectively (all P < .05). Combined treatment reduced Mb increments 1 hour postexercise by 54% and FABP increments 8 hours postexercise by 44% (all P < .05). A highly significant correlation existed between therapy-induced changes in plasma triglycerides and changes in postexercise increments of FABP and Mb. In conclusion, combined hyperlipidemia is associated with an increased exercise-induced release of muscle proteins, which is ameliorated by triglyceride-lowering intervention. As FABP is an indicator for ischemia-induced skeletal muscle pathology, a possible explanation is the impaired muscle blood flow during hypertriglyceridemia, which may be reversed by triglyceride-lowering intervention. The mechanism and clinical relevance of these findings remain to be investigated.

Long-term safety and efficacy of combination gemfibrozil and HMG-CoA reductase inhibitors for the treatment of mixed lipid disorders

BACKGROUND

Combinations of gemfibrozil and a 3-hydroxy-3-methylglutaryl (HMG) coenzyme A reductase inhibitor show promise in treating mixed lipid abnormalities. However, concern regarding the risk of myopathy and hepatic toxicity has limited the use of this combination. To determine the long-term safety and efficacy of this combination, we prospectively identified all patients placed on a combination of gemfibrozil and any HMG reductase inhibitor.

METHODS

Pravastatin, simvastatin, fluvastatin, lovastatin, or atorvastatin at incremental doses was combined with gemfibrozil (600 mg twice daily). Lipid profiles, creatine kinase levels, and aminotransferase levels were monitored. Two hundred fifty-two patients with established atherosclerosis receiving combination therapy for a mean of 2.36 +/- 1.52 years spanning a total of 593.6 patient-years were monitored.

RESULTS

In 148 patients, gemfibrozil was started before an HMG was added. The pretreatment total cholesterol level fell from 222 +/- 34 mg/dL to 181 +/- 26 mg/dL (P <.001) on combination therapy. HDL cholesterol level rose from 30 +/- 5 mg/dL to 36 +/- 7 mg/dL (P <.01), triglyceride level fell from 361 +/- 141 mg/dL to 212 +/- 101 mg/dL (P <.03). The ratio of total cholesterol to HDL fell from 7.6 +/- 1. 7 to 5.3 +/- 1.6 (P <.001). In 104 patients an HMG was begun before gemfibrozil was added. Pretreatment total cholesterol level fell from 246 +/- 54 mg/dL to 192 +/- 40 mg/dL on combination therapy (P <.01). HDL level rose from 33 +/- 9 mg/dL to 38 +/- 9 mg/dL (P <.03) and triglyceride level fell from 314 +/- 183 mg/dL to 183 +/- 93 mg/dL (P <.001). The ratio of total cholesterol to HDL fell from 7.9 +/- 3.6 to 5.2 +/- 1.4 (P <.001). In both groups the lipid profile on combination therapy was significantly better than that obtained on single-agent therapy. One episode of myopathy (0.4%) and one episode of aminotransferase level elevation (0.4%) of greater than 3 times upper limit of normal occurred. Both resolved with cessation of therapy without consequence.

CONCLUSIONS

Combinations of gemfibrozil and an HMG, compared with either agent alone, results in improved long-term control of lipid abnormalities in mixed lipid disorders. The low incidence of toxicity permits the use of combination therapy in patients at high risk of atherosclerotic complications.