Enhanced myopathy following administration of hypolipidemic agents under urethane anesthesia

The enhanced effect of urethane anesthesia on the serum creatine kinase (CPK) level following administration of hypolipidemic agents was examined to develop a convenient experimental screening method for drug-induced myopathy. After oral administration of a hypolipidemic agent to rats, 25% urethane solution was infused intravenously at a very low rate using a microinfusion pump. Blood samples were collected 7 h after drug administration and the risk of myopathy was evaluated based on the CPK level. When bezafibrate (BF), simvastatin (SV), or pravastatin (PV) (50-500 mg/kg) was orally administered under urethane infusion, enhanced elevation of the serum CPK level was observed dose dependently for BF and SV, but not for PV. The elevation of serum CPK was much higher with BF than with SV or PV. In addition, when SV or PV (50-500 mg/kg) was coadministered with 50 mg/kg of BF, there was a striking increase in the serum CPK level as compared with the drug alone. Without urethane infusion, no significant elevation in serum CPK level was observed even at a high dose of these hypolipidemic agents. These phenomena suggest that the urethane anesthesia enhanced the elevation of the serum CPK level following administration of hypolipidemic agents. We propose that this method is a simple and speedy screening test for drug-induced myopathy.

Evaluation of the phototoxic properties of some hypolipidemics in vitro: fenofibrate exhibits a prominent phototoxic potential in the UVA and UVB region

As some fibric acid derivatives have been reported to exhibit photosensitizing effects in vivo, the antilipemic drugs fenofibrate, bezafibrate, clofibrate, and gemfibrozil were tested for their phototoxic potential in vitro by a photohemolysis test using human erythrocytes and different irradiation sources. In this system only fenofibrate revealed strong phototoxic properties, which were dependent both on the drug concentration and the irradiation doses. Above a surface dose of 40 J/cm2 UVA of an UVA (320-400 nm)-rich irradiation source or 1.6 J/cm2 UVB/0.8 J/cm2 UVA of an UVB (280-320 nm)-rich irradiation source human red blood cells were completely photohemolysed in the presence of fenofibrate. Bezafibrate- and gemfibrozil-induced photohemolysis remained beneath 10%, and clofibrate showed no phototoxicity at all. As the phototoxic potential of fenofibrate lies in the UVB and UVA range, this might be of relevance with regard to clinical photosensitivity.

Atherogenic risk reduction in patients with dyslipidaemia. comparison between bezafibrate and lovastatin

OBJECTIVE

To examine the atherogenic risk-reducing effect of bezafibrate and lovastatin.

DESIGN, SETTING, PATIENTS, INTERVENTIONS

Double-blind, randomized clinical trial of male and female patients with moderate hypercholesterolaemia with or without hypertriglyceridaemia. Two months dietary treatment followed by 400 mg sustained release bezafibrate every day or 20 mg lovastatin every day for 6 months. Patients recruited (n = 561) and treated (n = 524) by primary care physicians throughout Austria.

MAIN OUTCOME MEASURES

Multifactorial assessment of atherogenic risk profile.

RESULTS

Bezafibrate increased high density lipoprotein cholesterol by 16%, lovastatin by 10% (P < 0.05). Bezafibrate decreased low density lipoprotein cholesterol by 20%, lovastatin by 27% (P < 0.001). Bezafibrate decreased total cholesterol by 15%, lovastatin by 18% (P < 0.001). Bezafibrate reduced triglycerides by 29%, lovastatin by 13% (P < 0.001); and fibrinogen by 9.4% and 3.0%, respectively. Fibrinogen reduction as a result of bezafibrate administration was dependent on starting levels. The risk ratio cholesterol:high density lipoprotein cholesterol (baseline both 6.1) reduction was 27% in both groups. The low:high density lipoprotein ratio (baseline: 4.1/4.2) reduction reached 31% and 34% respectively. Coronary events' probability (calculated from multifactorial risk functions) were greatly reduced by both agents (41%/33%). Hypertriglyceridaemic patients had a higher initial global coronary risk and profited more from treatment. Bezafibrate was significantly better tolerated (P < 0.001) than lovastatin; most events were gastrointestinal (6 vs 14, ns) or as a result of creatine phosphokinase elevations (3 vs 12, P < 0.05).

CONCLUSIONS

Both treatments significantly reduced the risk parameters for developing coronary heart disease, and calculated multifactorial coronary risk was similarly decreased. When selecting a drug for moderate dyslipidaemia and if haemostatic regulation is disturbed, the additional effect of bezafibrate on elevated fibrinogen levels should be considered.

[Toxic myopathies related to the administration of hypolipidemic agents: are the drugs the only things responsible?]

The characteristics are reported of five myopathies initially considered toxic in nature caused by the administration of blood lipid lowering agents. In three cases the final diagnosis was hypothyroidism, thus demonstrating the need to rule out the potential causes of secondary dyslipidemia before initiating therapy. Likewise, and because of the rare true muscle involvement from blood lipid lowering agents, it is necessary to investigate those diseases or factors enhancing muscle toxicity when it appears.

Iatrogenic profound hypoalphalipoproteinaemia: an unrecognised cause of very low HDL cholesterol

A significant reduction in plasma high density lipoprotein (HDL) cholesterol is a recognised consequence of treatment with probucol. By contrast, fibrate therapy in general has the opposite effect. We report two cases where the combination of probucol and a fibrate led to profoundly reduced plasma levels of HDL cholesterol associated with very low levels of apolipoprotein A-I (apoA-I). In the first, bezafibrate was added to probucol, and in the second, probucol added to a combination of simvastatin and fenofibrate. In both cases, plasma levels of HDL and apoA-I returned towards normal after discontinuation of one or both drugs, indicating that the reduction was reversible.

High-dose fluvastatin and bezafibrate combination treatment for heterozygous familial hypercholesterolemia

This study assessed the long-term use of fluvastatin, alone or in combination with bezafibrate, in patients with severe familial hypercholesterolemia who, in a previous study, did not achieve target levels (European Atherosclerosis Society) of low density lipoprotein cholesterol (LDL-C) with fluvastatin at 60 mg/day plus bezafibrate 200 mg/day, with or without cholestyramine (CME) at 8 g/day. This open-label study comprised 3 periods: period I, 6 weeks of fluvastatin at 40 mg twice daily (at breakfast and at bedtime); period II, fluvastatin at 80 mg/day (40 mg at breakfast, 40 mg at bedtime), and bezafibrate at 200 mg/day (at lunchtime) for 6 weeks in patients not achieving LDL-C target levels; and period III, force-titration of fluvastatin to 800 mg/day (as in period II) and bezafibrate at 400 mg/day (slow release) in patients receiving combination treatment. Patients were excluded if, during the previous study, they had experienced a serious drug-related adverse event or deterioration in liver or kidney function (liver enzymes > 3 times upper limit of normal). The standard physical and laboratory evaluations were performed at regular intervals. Lipid profiles were determined from 12-hour fasting blood samples. All adverse events occurring or worsening during the study, whether spontaneously reported or elicited by questioning, and regardless of relationship to study medication, were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term safety of statin-fibrate combination treatment in the management of hypercholesterolaemia in patients with coronary artery disease

OBJECTIVE

To evaluate the long-term safety profile of treatment with a statin-fibrate combination in a cohort of patients with documented coronary artery disease.

DESIGN

Retrospective cohort analytical study.

SETTING

District general hospital.

PATIENTS

102 (81 male and 21 female) hypercholesterolaemic (total cholesterol concentration > 6.5 mmol/l) patients with documented coronary artery disease and who had been treated with a statin-fibrate combination for over 1 year. Coronary artery disease was confirmed by angiography in 93 patients and by a positive (Bruce protocol) exercise test in the remainder. Fifty eight patients had a history of previous coronary bypass graft surgery.

INTERVENTIONS

Twice daily lipid lowering treatment was given, with the fibrate administered in the morning (either bezafibrate 400 mg (n = 101) or fenofibrate 200 mg (n = 1)) and the statin in the evening (either simvastatin 10 mg (n = 23), 20 mg (n = 72), or 40 mg (n = 2) or pravastatin 10 mg (n = 1) or 20 mg (n = 4)). Treatment continued for 1 (n = 9), 2 (n = 58), or 3 (n = 35) years.

MAIN OUTCOME MEASURES

Selected laboratory variables (total cholesterol concentration and liver (aspartate transaminase (AST)) and muscle enzyme (creatine kinase (CK)) activities) and documented symptomatology.

RESULTS

A mean (SD) total cholesterol concentration of 5.2 (0.8) mmol/l was achieved after combined treatment for 1 year which was maintained at annual follow up. Over a maximum 3 year follow up no patient reported myalgic symptoms and none had a measured CK activity > 10 times above nomal. Four men on a simvastatin-bezafibrate combination had a CK activity rise to less than three times normal. Fourteen patients with a negative history of alcohol excess (consumption < 21 units/week) had borderline raised AST values.

CONCLUSIONS

Statin-fibrate combination treatment for up to 3 years in a cohort of patients with coronary artery disease was not associated with serious disturbances in biochemical markers of muscle or liver function.

Treatment of primary hypercholesterolemia: fluvastatin versus bezafibrate

The effects of fluvastatin and bezafibrate on lipids, lipoproteins, and apoproteins (apo) were investigated in a multicenter randomized, double-blind, parallel-group study. After 8 weeks of strictly controlled (computer-based assessment) dietary stabilization, patients with primary hypercholesterolemia (low-density lipoprotein cholesterol [LDL-C] > or = 160 mg/dL; triglycerides < or = 300 mg/dL) were enrolled into a 6-week placebo phase. Altogether, 131 patients were randomized to receive either fluvastatin at 40 mg once daily (n = 64; mean age 53 years) or bezafibrate at 400 mg once daily (n = 67; mean age 52 years) for 12 weeks. Compliance with the diet was monitored (3-day food records) after 6 and 12 weeks. Fluvastatin led to significant reductions in LDL-C (-23%), total cholesterol (-17%), LDL-C/high-density lipoprotein cholesterol (HDL-C) (-24%) and apo B (-19%). Fluvastatin significantly increased LpA-I (+8%) and apo E (+20%). Bezafibrate produced significant reductions in LDL-C (-17%), total cholesterol (-13%), LDL-C/HDL-C (-24%), triglycerides (-28%), apo B (-15%), and LpA-I (-10%) and significantly increased HDL-C (+12%), apo A-I (+9%), apo A-II (+30%), apo E (+14%), and Lp(a) (+3%). No clinically notable increases in levels of liver enzymes or creatine phosphokinase were observed with either treatment. Both treatments were well tolerated. There was a low incidence of adverse events that tended to be mild and included headache, muscular pain, angina, and dyspepsia. The frequency of adverse events was similar in both treatment groups, and no significant differences in dietary behavior were observed. In conclusion, fluvastatin is a well tolerated 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor for the treatment of primary hypercholesterolemia. Effects of fluvastatin on LpA-I occur irrespective of changes in HDL-C.

Treatment of severe, resistant familial combined hyperlipidemia with a bezafibrate-lovastatin combination

Familial combined hyperlipidemia (FCHL) is a common lipid disorder characterized by high levels of cholesterol, triglycerides, or both. The basic metabolic abnormality is overproduction of apolipoprotein B-100. High atherogenicity has been attributed to all forms of FCHL. We evaluated combined bezafibrate-lovastatin therapy in 10 patients (9 men and 1 woman) with FCHL and markedly high cholesterol and triglyceride levels who were at high risk of coronary artery disease and who had not responded to diet and bezafibrate treatment alone. Eight patients had coronary artery disease, 6 had hypertension, and 3 had noninsulin-dependent diabetes mellitus. Lovastatin 20 mg/day was added to the bezafibrate 600 mg/day regimen for 6 weeks; the lovastatin dosage was then doubled to 40 mg/day for an additional 6 weeks. The addition of 20 mg of lovastatin resulted in decreases of 15%, 20%, and 13% in total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels, respectively. Increasing the dose of lovastatin to 40 mg resulted in further moderate decreases of 4%, 3%, and 8% in total cholesterol, LDL cholesterol, and triglycerides, respectively, compared with the 20 mg/day dosage. Although previous reports have emphasized the potential side effects of combination treatment with lovastatin and fibric acid derivatives, our patients tolerated the regimen well, with no significant subjective complaints or laboratory abnormalities. The bezafibrate-lovastatin combination is a possible therapeutic option for severe, resistant FCHL, but close medical supervision is needed because of potential side effects.

Bezafibrate-induced myopathy: no evidence for defects in muscle metabolism

A 58-year-old man with chronic renal failure developed severe muscle pain and tenderness 1 week after starting bezafibrate 400 mg daily. Serum creatine kinase was 32,280 U/l. Muscle biopsy revealed scattered necrotic fibers and mild type 2b atrophy. Muscle total and free carnitine were at the upper limits of the normal range. Biochemical investigations of muscle homogenate showed normal carnitine pelmityl transferase (CPT) as well as normal individual glycolytic and mitochondrial enzyme activities. Withdrawal of the drug was followed by rapid clinical improvement. Our study casts doubt on the hypothesis that bezafibrate is able to affect muscle metabolic pathways. It is likely that the drug acts on cholesterol constituents of the muscle membrane, producing discontinuities of the sarcolemma and initiating cell necrosis.

Photosensitivity induced by fibric acid derivatives and its relation to photocontact dermatitis to ketoprofen

BACKGROUND

Photosensitivity reactions to fibric acid derivatives are not well understood and have been rarely reported.

OBJECTIVE

The aim of this study was to describe two cases of photosensitivity, one induced by fenofibrate and one by bezafibrate; to study the in vivo photosensitizing potential of these drugs; and to evaluate the possibility of cross-reactivity between fenofibrate and ketoprofen.

METHODS

Patch and photopatch tests with fibric acid derivatives and ketoprofen were performed in the patients, in 12 normal volunteers, and in 7 patients with photopatch-proven photocontact dermatitis to ketoprofen. Phototesting studies were performed both while the patients were taking the drugs and after withdrawal of them, as well as in a group of 18 hyperlipemic volunteers without history of photosensitivity who were taking therapeutic doses of fenofibrate or bezafibrate for 2 to 3 months.

RESULTS

Positive photopatch test responses to ketoprofen and to fenofibrate were obtained only in the first patient, who also had a weaker positive ordinary patch test response to the latter. Five patients photosensitized to ketoprofen also had a positive patch test to fenofibrate. Phototesting studies were abnormal in both patients but normal in all volunteers.

CONCLUSION

An association between systemic photosensitivity to fenofibrate and photocontact sensitivity to ketoprofen seems to exist. The structural similarities of these chemicals favor cross-reactivity.

[Bezafibrate myopathy in two patients with chronic renal failure]

Case 1, a 60-year-old man and case 2, a 70-year-old man had several year history of chronic renal failure with hypertension and hyperlipidemia due to diabetes mellitus. Treatment of hyperlipidemia was started by oral bezafibrate intake 1,200 mg per day in case 1 and 400 mg per day in case 2 respectively. Three to fourteen days later, both patients noticed symmetrical muscle pain and weakness. Then the symptoms worsened and they were hospitalized. At the time of admission, both patients revealed weakness in the proximal muscles of their upper and lower limbs and the serum creatine kinase and myoglobin levels were remarkably elevated. Myoglobinuria was also noted. Routine light microscopic examination of biopsied quadriceps femoris muscles of two patients showed scattered necrotic muscle fibers, some of which were under phagocytosis. The symptoms of the patients were immediately resolved after the drug was discontinued. Serum concentration of bezafibrate was remarkably elevated during treatment. Thus the diagnosis was established as having bezafibrate induced myopathy and, as far as we know, this is the first report of bezafibrate induced myopathy in Japan. On the basis of the above description, bezafibrate may induce muscle damage if dose is excess over the renal capacity. Extreme caution is warranted when the patient is placed on bezafibrate and has renal dysfunction. Strict dose adjustment is necessary in taking account of renal function to avoid muscle damage including rhabdomyolysis.

Effects of combined bezafibrate-simvastatin appraised in healthy subjects

The occurrence of clinical and biochemical side effects of bezafibrate (400 mg daily) or simvastatin (20 mg daily) alone or combined was appraised in 13 healthy male normolipidemic subjects according to a single blind design. Each period of 2 weeks of treatment with bezafibrate or simvastatin or bezafibrate plus simvastatin was followed by a period of placebo (1 week). No subjects experienced myalgia or muscle weakness. Plasma creatine kinase (CK) elevations, particularly skeletal muscle CK (CK-MM), were observed in 6 subjects: 11 times during different placebo periods, 5 times on bezafibrate, 4 times on simvastatin, and 4 times on combined bezafibrate-simvastatin, but never reached 1,600 IU/L. Only a trend to an increase of CK mean values on combined bezafibrate-simvastatin was shown. The hepatic transaminase and gamma-glutamyltransferase activities remained unmodified throughout the trial, unlike alkaline phosphatase activity, which fell on bezafibrate and on bezafibrate plus simvastatin. The low-density lipoprotein cholesterol level was more reduced with simvastatin than with bezafibrate. The addition of bezafibrate to simvastatin did not decrease it further. Lecithin:cholesterol acyltransferase activity expressed as fractional esterification rate was enhanced only on simvastatin and bezafibrate-simvastatin.