Lipid lowering treatment with bezafibrate in patients on chronic haemodialysis: pharmacokinetics and effects

Choosing the right chronic medication for hemodialysis patients. A short ABC for the dialysis nephrologist

BACKGROUND

Adapting drug treatments for patients on hemodialysis with multiple chronic pathologies is a complex affair. When prescribing a medication, the risk-benefit analysis usually focuses primarily on the indication of the drug class prescribed. However, the pharmacokinetics of the chosen drug should also be taken into account. The purpose of our review was to identify the drugs to be favored in each therapeutic class, according to their safety and pharmacokinetic profiles, for the most common chronic diseases in patients on chronic hemodialysis.

METHODS

We conducted a narrative review of the literature using Medline and Web of Science databases, targeting studies on the most commonly-prescribed drugs for non-communicable diseases in patients on chronic hemodialysis.

RESULTS

The search identified 1224 articles, 95 of which were further analyzed. The main classes of drugs included concern the cardiovascular system (anti-hypertensives, anti-arrhythmics, anti-thrombotics, hypocholesterolemics), the endocrine and metabolic pathways (anti-diabetics, gastric anti-secretory, anticoagulant, thyroid hormones, anti-gout) and psychiatric and neurological disorders (antidepressants, anxiolytics, antipsychotics and anti-epileptics).

CONCLUSION

We report on the most often prescribed drugs for chronic pathologies in patients on chronic hemodialysis. Most of them require adaptation, and in some cases one better alternative stands out among the drug class. More pharmacokinetic data are needed to define the pharmacokinetics in the various dialysis techniques.

Treatment of fibrate-induced rhabdomyolysis with plasma exchange in ESRD

Hypertriglyceridemia is a common metabolic disorder in patients with chronic renal failure. Fibrate derivatives are often used for lipid lowering in this population with adjusted dosage. However, fibrate-related adverse reaction still occasionally occurs. The authors report a case of end-stage renal disease in a patient who underwent hemodialysis regularly, taking a reduced dosage of bezafibrate (200 mg/d) for refractory hypertriglyceridemia. She did not take any statins, cyclosporine, monoamine oxidase inhibitors, or warfarin concurrently. Rhabdomyolysis was complicated along with an increased serum bezafibrate level. Plasma exchange was performed, which dramatically decreased the level of bezafibrate, and rhabdomyolysis resolved rapidly thereafter. A lower dose of bezafibrate, 200 mg every third day, was prescribed with cautious monitoring of symptoms and laboratory parameters, and better triglyceride control was achieved uneventfully. This is the first report using plasma exchange to remove excessive bezafibrate, a highly protein-bound molecule that is unlikely to be cleared by hemodialysis in an end-stage renal disease patient with serious adverse reaction caused by accumulation of bezafibrate. In contrast to a traditional wait-and-see strategy, plasma exchange seems to be a safe and effective treatment in addition to supportive care for rhabdomyolysis in such clinical scenarios.

Lipid abnormalities in chronic uremic patients. Response to treatment with gemfibrozil

Seventy-four patients with end stage renal failure were studied. Forty-six of them were on hemodialysis (HD) while 28 were on continuous ambulatory peritoneal dialysis (CAPD). In addition 56 nondialysis chronic renal failure (NDCRF) patients with various degree of renal failure were also studied. In all groups serum triglyceride concentrations were significantly higher and HDL cholesterol concentrations were significantly lower compared to age- and sex-matched controls. Total and LDL cholesterol were significantly higher in the NDCRF and CAPD patients compared to controls. In 55 patients (20 on HD, 13 on CAPD and 22 NDCRF) with severe hypertriglyceridemia or diminished HDL cholesterol gemfibrozil 300 mg b.i.d. per os was given for 6 months. Drug treatment reduced significantly serum triglycerides in all groups of patients and increased the levels of HDL cholesterol in CAPD patients. Moreover, a statistically significant decrease of the levels of total and LDL cholesterol was noticed in HD and NDCRF patients. During treatment no significant side effects were observed and liver and muscle enzymes remained within normal values.

Cardiovascular risk factors in chronic renal failure and hemodialysis populations

Cardiovascular disease is the leading cause of death in patients with end-stage renal disease (ESRD). Risk factors for cardiovascular disease, including hypertension, lipid abnormalities, left ventricular hypertrophy (LVH), and glucose intolerance, are present more frequently in patients with chronic renal failure than in the general population, even before the onset of replacement therapy. The prevalence, pathogenesis, and significance of these factors in the uremic population are examined, and the potential roles of intervention are reviewed. Evidence suggests, but is not conclusive, that these factors are of predictive value for cardiovascular complications in patients with chronic renal failure. The effect of modification of these factors on cardiovascular morbidity and mortality in this population, especially in the early stages of renal failure, is an important area for further study.

Effects of HMG-CoA reductase inhibitors in hypercholesterolemic patients on hemodialysis

The efficacy of lovastatin and simvastatin, competitive inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase, was investigated in 40 hemodialysis (HD) patients displaying hypercholesterolemia and moderate hypertriglyceridemia (selection of 40 patients required screening of 700 hemodialysis patients). After a four-week placebo period, lovastatin or simvastatin was administered to two groups of 20 patients in increasing doses over a period of three months. Thirty-six patients completed the study. Lovastatin (1st month 20 mg; 2nd and 3rd months 40 mg day-1) and simvastatin (1st month 10 mg, 2nd month 20 mg and 3rd month 40 mg day-1) reduced total serum cholesterol from 280.3 +/- 9.4 to 213.0 +/- 6.7 (-24%) and 295.0 +/- 12.2 to 202.3 +/- 8.9 mg/dl (-31.4%), LDL cholesterol from 161.9 +/- 10.7 to 112.1 +/- 7.9 (-30.8%) and 181.8 +/- 14.7 to 107.4 +/- 8.1 mg/dl (-40.9%), as well as apolipoprotein B (apo B) from 116.0 +/- 6.6 to 83.3 +/- 3.7 (-28.2%) and 134.4 +/- 8.2 to 84.1 +/- 5.3 mg/dl (-37.4%), respectively. Furthermore, the ratio of LDL apo B/LDL cholesterol increased significantly (0.63 +/- 0.02 vs. 0.71 +/- 0.05 and 0.63 +/- 0.02 vs. 0.66 +/- 0.02, respectively). Another remarkable effect was the reduction of cholesterol concentration in VLDL (72.4 +/- 8.9 vs. 47.3 +/- 6.8 [lovastatin] and 78.3 +/- 11.1 vs. 50.7 +/- 8.8 mg/dl [simvastatin], respectively). Therefore, the ratio of triglycerides/cholesterol in VLDL increased (3.2 +/- 0.2 vs. 3.8 +/- 0.3 and 3.2 +/- 0.2 vs. 4.0 +/- 0.2, respectively), indicating VLDL formation poor in cholesterol and rich in triglycerides.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of gemfibrozil and other fibric acid derivatives on blood lipids and lipoproteins

Fibric acid derivatives (FADs) are a class of drugs that have been shown to reduce the production of very low-density lipoprotein (VLDL) while enhancing VLDL clearance due to the stimulation of lipoprotein lipase activity. The drugs can reduce plasma triglyceride levels while raising high-density lipoprotein (HDL) cholesterol levels. Their effects on low-density lipoprotein (LDL) cholesterol levels are less marked and more variable. There is evidence that oral gemfibrozil (Lopid, Parke-Davis, Morris Plains, NJ) can reduce the risk of serious coronary events, specifically in those patients who had elevations of both LDL cholesterol levels and total plasma triglyceride levels with lower HDL cholesterol levels. Newer FADs (bezafibrate, ciprofibrate, fenofibrate) have been shown to have greater efficacy in reducing LDL cholesterol than gemfibrozil but, in general, these drugs are not as effective as the other primary drugs used to lower LDL levels. The FADs are also used to treat adult patients with very high levels of triglycerides who have pancreatitis and whose disease cannot be managed with dietary therapy. The FADs are well tolerated, with dyspepsia and abdominal pain the most common adverse effects. A small risk of cholelithiasis exists with these drugs, and caution should be used when combining these drugs with HMG-CoA reductase inhibitors because the combination increases the incidence of hyperlipidemic myositis and rhabdomyolysis.

Inhibition of fatty acid biosynthesis by bezafibrate in different rat cells

Bezafibrate is one of the main drugs used in the treatment of human hyperlipemic diseases. Its action on the biosynthesis of fatty acids has been studied and the following conclusions have been drawn: (1) Lipogenesis from glucose is inhibited in hepatocytes and adipocytes isolated from "refed" rats previously treated with bezafibrate. (2) Lipogenesis from glucose is inhibited by bezafibrate in hepatocytes and adipocytes isolated from "refed" rats. (3) Lipogenesis from glucose is also inhibited by bezafibrate in acini isolated from lactating rats. These results show that bezafibrate is an inhibitor of fatty acid synthesis.

Magnesium pyridoxal 5-phosphate glutamate reduces hyperlipidaemia in patients with chronic renal insufficiency

Chronic renal insufficiency is often accompanied by hyperlipidaemia and subsequent coronary heart disease. Two groups of 15 patients with serum creatinine greater than 2 mg/100 ml and serum cholesterol less than 250 mg/100 ml were given 3 x 50 mg magnesium pyridoxal 5-phosphate glutamate (MPPG) or placebo for 12 weeks in a double-blind, randomised study. Total cholesterol in the MPPG group (282.4 mg.100 ml-1) was lower than in the placebo group (354.3 mg.100 ml-1) after 12 weeks of treatment. Triglycerides in the MPPG group were 265.1 mg.100 ml-1 compared to 361.9 mg.100 ml-1. After 12 weeks on MPPG the LDL/HDL ratio of 3.56 was lower than in the placebo group-6.83. Side effects in the MPPG group were similar to those in the placebo group. Thus, MPPG was an effective antihyperlipidaemic agent in patients with renal insufficiency.