Efficacy and safety of pravastatin in the treatment of patients with type I or type II diabetes mellitus and hypercholesterolemia

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.

Efficacy and safety of high-dose pravastatin in hypercholesterolemic patients with well-compensated chronic liver disease: Results of a prospective, randomized, double-blind, placebo-controlled, multicenter trial

The hepatotoxic potential of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in patients with underlying chronic liver disease remains controversial. We performed a multicenter, randomized, double-blind, placebo-controlled, parallel-group trial that compared pravastatin (80 mg) to a placebo administered once daily to hypercholesterolemic subjects greater than 18 years of age with at least a 6-month history of compensated chronic liver disease and with a low-density lipoprotein cholesterol (LDL-C) level greater than or equal to 100 mg/dL and a triglyceride (TG) level lower than 400 mg/dL. The efficacy was determined by the percentage change in LDL-C [along with the total cholesterol (TC), high-density lipoprotein cholesterol, and TG] from the baseline to week 12. The safety was analyzed by the proportion of subjects who developed at least 1 alanine aminotransferase (ALT) value greater than or equal to 2 times the upper limit of normal for those with normal ALT at the baseline or a doubling of the baseline ALT for those with elevated ALT at the baseline during 36 weeks of treatment. A total of 630 subjects were screened, and 326 subjects were randomized; nonalcoholic fatty liver disease was present in 64%, and chronic hepatitis C was present in 23%. In the intent-to-treat population, pravastatin (80 mg/day) significantly lowered the mean LDL-C, TC, and TG values at week 12 and at other times (weeks 4, 8, 24, and 36) in comparison with the placebo. The incidence of subjects who met the primary prespecified ALT event definition was lower in the pravastatin group at all times over the 36 weeks of therapy in comparison with the placebo group, although the difference was not statistically significant. No differences were seen on the basis of the baseline ALT values or among the different liver disease groups.

CONCLUSION

High-dose pravastatin (80 mg/day) administered to hypercholesterolemic subjects with chronic liver disease significantly lowered LDL-C, TC, and TGs in comparison with the placebo and was safe and well tolerated. The concern over an increased potential for statin-induced hepatotoxicity in patients with chronic liver disease appears to be lessened on the basis of these results.

Rosuvastatin and fenofibrate alone and in combination in type 2 diabetes patients with combined hyperlipidaemia

The aim of this study was to evaluate the effects of rosuvastatin and fenofibrate alone and in combination in type 2 diabetes associated with combined hyperlipidaemia. A total of 216 patients with total cholesterol >/=200 mg/dl (>/=5.17 mmol/l) and triglycerides >/=200 and <800 mg/dl (>/=2.26 and <9.03 mmol/l) were randomised to one of two placebo groups, rosuvastatin 5 mg or rosuvastatin 10 mg for 6 weeks (fixed-dose phase). During the subsequent 18-week dose-titration phase, one placebo group received titrated rosuvastatin 10, 20 and 40 mg (placebo/rosuvastatin); one placebo group received titrated fenofibrate 67 mg once, twice and three times daily (placebo/fenofibrate); and patients receiving 5 or 10 mg rosuvastatin received titrated fenofibrate as above (rosuvastatin 5mg/fenofibrate and rosuvastatin 10 mg/fenofibrate groups). Doses were increased at 6-week intervals if low-density lipoprotein (LDL) cholesterol remained >50 mg/dl (>1.3 mmol/l). At 24 weeks, the placebo/rosuvastatin group and placebo per fenofibrate group had triglyceride reductions of 30.3% versus 33.6%, respectively (P = NS), and LDL cholesterol was reduced by 46.7% in the rosuvastatin group and increased by 0.7% in the fenofibrate group (P < 0.001). The triglyceride reduction in the rosuvastatin 10 mg/fenofibrate group (47.1%) was significantly greater than in the placebo/rosuvastatin group (P = 0.001), with no significant differences in other lipid measures found between these two groups. No significant differences in effect on high-density lipoprotein (HDL) were observed among treatment groups. In the fixed-dose phase, rosuvastatin 5 and 10 mg reduced triglycerides by 24.5 and 29.5%, respectively, and decreased LDL cholesterol by 40.7 and 45.8%, respectively. All treatments were well tolerated. These results indicated that rosuvastatin produces marked reductions in triglycerides and LDL cholesterol when used alone or in combination with fenofibrate in type 2 diabetes patients with elevated cholesterol and triglyceride levels and may constitute a valuable treatment option in the diabetic population.

Compliance with national guidelines in patients with diabetes in a family practice clinic

STUDY OBJECTIVE

To assess whether clinicians are treating patients with both type 2 diabetes and hyperlipidemia according to national goals for blood pressure, low-density lipoprotein cholesterol (LDL), and glucose levels.

DESIGN

Retrospective chart review.

SETTING

University-based family medicine teaching practice.

PATIENTS

One hundred twenty-four patients with both type 2 diabetes and hyperlipidemia.

MEASUREMENTS AND MAIN RESULTS

Sixty-nine patients (58%) met the National Cholesterol Education Program Adult Treatment Panel II's goals for LDL (< 130 mg/dl for primary prevention and < 100 mg/dl for secondary prevention). Only 47 patients (38%) were in compliance with national standards for both systolic and diastolic blood pressures. The mean hemoglobin A1c (A1C) level was 8.6%; 27 patients (21.8%) had A1C levels below 7%.

CONCLUSION

A high percentage of patients in our family practice clinic met their goals for reducing lipid levels, but more aggressive therapy is necessary to attain glucose and blood pressure goals. Data from this study emphasize the need for understanding which factors influence clinicians' treatment decisions.

Insulin resistance syndrome and type 2 diabetes mellitus

Patients with type 2 diabetes mellitus have an elevated risk of morbidity and mortality from cardiovascular disease. This risk is partly attributable to an increased prevalence of classic coronary artery disease risk factors and partly because of hyperglycemia itself and a highly atherogenic lipid profile. The altered composition of lipoproteins and lipids in type 2 diabetic patients, termed diabetic dyslipidemia, is characterized by: (1) elevated levels of triglyceride; (2) normal levels of total and low-density lipoprotein cholesterol (LDL-C); (3) reduced levels of high-density lipoprotein cholesterol (HDL-C); (4) elevated levels of apolipoprotein B; (5) a preponderance of small, dense LDL particles; and (6) increased levels of cholesterol-rich very-low-density lipoprotein. In most cases, diabetic dyslipidemia is preceded by hyperinsulinemia resulting from insulin resistance. Because patients with type 2 diabetes and insulin resistance are at a markedly increased risk of atherosclerosis, and because strict control of glycemia has proved beneficial in reducing microangiopathy but not macroangiopathy, treatment of diabetic dyslipidemia should be aggressive. Target levels have, therefore, been set at <2.6 mmol/L (100 mg/dL) for LDL-C, <2.3 mmol/L [200 mg/dL] for triglycerides, and >1.15 mmol/L (45 mg/dL) for HDL-C. Trial data suggest that these target levels are likely to be achieved with statins, if necessary, in combination with fibrates or nicotinic acid derivatives. Furthermore, in large-scale clinical trials (eg, Scandinavian Simvastatin Survival Study [4S] and the Cholesterol and Recurrent Events [CARE] study), it has been demonstrated that lipid lowering can appreciably reduce cardiovascular events in diabetic patients.

Treating dyslipidaemia in non-insulin-dependent diabetes mellitus -- a special reference to statins

Patients with non-insulin-dependent diabetes (NIDDM) have an increased incidence of ischaemic heart disease (IHD) when compared with nondiabetic subjects. In addition, they have a worse prognosis after their first myocardial infarction (MI). According to the recent USA recommendations, the threshold for initiation of dietary intervention in diabetic subjects is an LDL greater than 2.6 mmol/l, with the goal to achieve levels less than 2.6 mmol/l (100 mg/dl). This is also the threshold for initiation and treatment goal for pharmacological intervention in diabetic subjects, unless they are completely free of IHD, peripheral vascular disease or cerebrovascular disease and have no other IHD risk factors. In the latter circumstances, the threshold for treatment is an LDL greater than 3.38 mmol/l (130 mg/dl), with the goal to achieve levels less than 3.38 mmol/l. The HMG-CoA reductase inhibitors (statins) can improve the lipid profile effectively and safely in NIDDM. Results from post hoc analyses of diabetic subgroups in the large intervention trials suggest that some statins significantly reduce the risk for IHD-related mortality/morbidity. However, because these results are derived from secondary prevention trials, we cannot be sure if these benefits apply to all diabetic subjects or only to those who already have IHD. Nevertheless, it seems logical to assume that this benefit also applies to NIDDM patients who do not have IHD because they share a similar vascular risk as nondiabetic subjects who have IHD. Intervention trials using statins and fibrates, alone or in combination, in NIDDM are under way. In a few years these trials will provide definitive end-point-based evidence in this high-risk group of patients.

Efficacy and safety of atorvastatin in hyperlipidemic, type 2 diabetic patients. A 34-week, multicenter, open-label study

Hyperlipidemia is common in type 2 diabetic patients and is an independent risk factor for cardiovascular disease. The aim of this trial was to evaluate the efficacy and safety of once-daily atorvastatin 10-80 mg for the treatment of hyperlipidemia in type 2 diabetics with plasma low-density lipoprotein cholesterol (LDL-C) levels exceeding 3.4 mmol/l (130 mg/dl). One hundred and two patients met the study criteria and received 10 mg/day atorvastatin. Patients who reached the target LDL-C level of </=2.6 mmol/l (100 mg/dl) maintained the same dosage regimen until they had completed 16 weeks of treatment. Patients not reaching the target LDL-C underwent dose titration to atorvastatin 20, 40 and 80 mg/day at Weeks 4, 8 and 12, respectively. All 88 patients who completed the study attained target LDL-C levels and 52 (59%) of patients achieved the target goal at the starting dose of atorvastatin 10 mg/day. In this group the differences between baseline and post-treatment values for LDL-C were 4.3+/-0.7 mmol/l (166+/-26 mg/dl) versus 2. 2+/-0.4 mmol/l (87+/-14 mg/dl) (P<0.0001), respectively, a decrease of 47%. Similar trends were observed for total cholesterol, triglycerides, very low-density lipoprotein cholesterol and apolipoprotein B levels. The safety profile of atorvastatin in these patients was highly favorable and similar to those reported with other statins. Only one patient withdrew due to a possible drug-related adverse event. These data confirm the marked efficacy and safety of atorvastatin in type 2 diabetic patients with hyperlipidemia and the efficacy of atorvastatin 10 mg in helping patients attain their LDL-C goal.

Comparative tolerability of the HMG-CoA reductase inhibitors

The availability of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has revolutionised the treatment of lipid abnormalities in patients at risk for the development of coronary atherosclerosis. The relatively widespread experience with HMG-CoA therapy has allowed a clear picture to emerge concerning the relative tolerability of these agents. While HMG-CoA reductase inhibitors have been shown to decrease complications from atherosclerosis and to improve total mortality, concern has been raised as to the long term safety of these agents. They came under close scrutiny in early trials because ocular complications had been seen with older inhibitors of cholesterol synthesis. However, extensive evaluation demonstrated no significant adverse alteration of ophthalmological function by the HMG-CoA reductase inhibitors. Extensive experience with the potential adverse effect of the HMG-CoA reductase inhibitors on hepatic function has accumulated. The effect on hepatic function for the various HMG-CoA reductase inhibitors is roughly dose-related and 1 to 3% of patients experience an increase in hepatic enzyme levels. The majority of liver abnormalities occur within the first 3 months of therapy and require monitoring. Rhabdomyolysis is an uncommon syndrome and occurs in approximately 0.1% of patients who receive HMG-CoA reductase inhibitor monotherapy. However, the incidence is increased when HMG-CoA reductase inhibitors are used in combination with agents that share a common metabolic path. The role of the cytochrome P450 (CYP) enzyme system in drug-drug interactions involving HMG-CoA reductase inhibitors has been extensively studied. Atorvastatin, cerivastatin, lovastatin and simvastatin are predominantly metabolised by the CYP3A4 isozyme. Fluvastatin has several metabolic pathways which involve the CYP enzyme system. Pravastatin is not significantly metabolised by this enzyme and thus has theoretical advantage in combination therapy. The major interactions with HMG-CoA reductase inhibitors in combination therapy involving rhabdomyolysis include fibric acid derivatives, erythromycin, cyclosporin and fluconazole. Additional concern has been raised relative to overzealous lowering of cholesterol which could occur due to the potency of therapy with these agents. Currently, there is no evidence from clinical trials of an increase in cardiovascular or total mortality associated with potent low density lipoprotein reduction. However, a threshold effect had been inferred by retrospective analysis of the Cholesterol and Recurrent Events study utilising pravastatin and the role of aggressive lipid therapy is currently being addressed in several large scale trials.

Efficacy of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors in the treatment of patients with hypercholesterolemia: a meta-analysis of clinical trials

Recent studies have documented the long-term impact of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors on mortality and morbidity related to coronary heart disease, establishing the link between lowering cholesterol levels and reducing cardiac events. Our study was a comparative literature review and meta-analysis of the efficacy of four HMG-CoA reductase inhibitors-fluvastatin, lovastatin, pravastatin, and simvastatin-used in the treatment of patients with hypercholesterolemia. The data sources for our meta-analysis of the efficacy of these cholesterol-lowering agents were 52 randomized, double-masked clinical trials with at least 25 patients per treatment arm. The results showed all four agents to be effective in reducing blood cholesterol levels. We computed summary efficacy estimates for all published dose strengths for the four agents. Fluvastatin 20 mg/d reduced low-density lipoprotein cholesterol (LDL-C) levels by 21.0% and total cholesterol (total-C) levels by 16.4%; fluvastatin 40 mg/d reduced these levels by 23.1% and 17.7%, respectively. Lovastatin 20 mg/d reduced LDL-C levels by 24.9% and total-C levels by 17.7%; lovastatin 80 mg/d reduced these levels by 39.8% and 29.2%, respectively. Pravastatin 10 mg/d reduced LDL-C levels by 19.3% and total-C levels by 14.0%; pravastatin 80 mg/d reduced these levels by 37.7% and 28.7%, respectively. Simvastatin 2.5 mg/d reduced LDL-C levels by 22.9% and total-C levels by 15.7%; simvastatin 40 mg/d reduced these levels by 40.7% and 29.7%, respectively. The results of our meta-analysis can be used in conjunction with treatment objectives and comparative cost-effectiveness data for these agents to decide appropriate therapeutic alternatives for individual patients.

Pravastatin. A reappraisal of its pharmacological properties and clinical effectiveness in the management of coronary heart disease

Pravastatin is an HMG-CoA reductase inhibitor which lowers plasma cholesterol levels by inhibiting de novo cholesterol synthesis. Pravastatin produces consistent dose-dependent reductions in both total and low density lipoprotein (LDL)-cholesterol levels in patients with primary hypercholesterolaemia. Favourable changes in other parameters such as total triglyceride and high density lipoprotein (HDL)-cholesterol levels are generally modest. Combination therapy with other antihyperlipidaemic agents such as cholestyramine further enhances the efficacy of pravastatin in patients with severe dyslipidaemias. Available data suggest that pravastatin is effective in elderly patients and in patients with hypercholesterolaemia secondary to diabetes mellitus or renal disease. The benefit of cholesterol-lowering in terms of patient outcomes is currently an area of considerable interest. Recently completed regression studies (PLAC I, PLAC II, KAPS and REGRESS) show that pravastatin slows progression of atherosclerosis and lowers the incidence of coronary events in patients with mild to moderately severe hypercholesterolaemia and known coronary heart disease. Large scale primary (WOSCOPS) and secondary (CARE) prevention studies, moreover, demonstrate that pravastatin has beneficial effects on coronary morbidity and mortality. In WOSCOPS, all-cause mortality was reduced by 22%. Pravastatin is generally well tolerated by most patients (including the elderly), as evidenced by data from studies of up to 5 years in duration. As with other HMG-CoA reductase inhibitors, myopathy occurs rarely (< 0.1% of patients treated with pravastatin): approximately 1 to 2% of patients may present with raised serum levels of hepatic transaminases. Thus, with its favourable effects on cardiovascular morbidity/mortality and total mortality, pravastatin should be considered a first-line agent in patients with elevated cholesterol levels, multiple risk factors or coronary heart disease who are at high risk of cardiovascular morbidity.