Clofibrate as an Adjunct to Phototherapy for Unconjugated Hyperbilirubinemia in Term Neonates.

OBJECTIVE: To evaluate the efficacy of oral clofibrate as an adjunct to phototherapy for unconjugated hyperbilirubinemia in term neonates. METHODS: This randomized controlled trial was done in the level III neonatal intensive care unit (NICU) of a tertiary care hospital. Ninety term neonates with unconjugated hyperbilirubinemia with serum bilirubin 15-25 mg/dl were randomized to either intervention group (single dose of clofibrate in a dose of 50 mg/kg prior to starting phototherapy) or standard care group (only phototherapy). Primary outcome was absolute fall in bilirubin by 48 h. Secondary outcomes were duration of phototherapy, absolute fall in bilirubin levels at 12, 24, 36, 48 h, need for exchange transfusion and incidence of side-effects. RESULTS: After 48 h of intervention, significantly lower bilirubin levels were noted in the intervention group compared to standard care group with a mean difference of 7 mg/dl (95% CI 6.7 mg/dl to 7.2 mg/dl). Duration of phototherapy required was less in the intervention group compared to standard care group with mean difference of 23.82 h (95% CI 30.46 h to 17.18 h). Exchange transfusion was needed for 4 neonates in the standard care group and none in the intervention group. No side-effects were noted with clofibrate. CONCLUSIONS: Single dose clofibrate prior to starting phototherapy in term neonates with uncomplicated unconjugated hyperbilirubinemia reduces the duration of phototherapy significantly.

Nonstatin therapies for management of dyslipidemia: a review.

PURPOSE: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the United States. Recently published cholesterol treatment guidelines emphasize the use of statins as the preferred treatment strategy for both primary and secondary prevention of CVD. However, the optimal treatment strategy for patients who cannot tolerate statin therapy or those who need additional lipid-lowering therapy is unclear in light of recent evidence that demonstrates a lack of improved cardiovascular outcomes with combination therapy. The purpose of this review is to summarize and interpret evidence that evaluates nonstatin drug classes in reducing cardiovascular outcomes, to provide recommendations for use of nonstatin therapies in clinical practice, and to review emerging nonstatin therapies for management of dyslipidemia. METHODS: Relevant articles were identified through searches of PubMed, International Pharmaceutical Abstracts, and the Cochrane Database of Systematic Reviews by using the terms niacin, omega-3 fatty acids (FAs), clofibrate, fibrate, fenofibrate, fenofibric acid, gemfibrozil, cholestyramine, colestipol, colesevelam, ezetimibe, proprotein convertase subtilisin/kexin 9 (PCSK9), cholesteryl ester transfer protein (CETP), and cardiovascular outcomes. Only English language, human clinical trials, meta-analyses, and systematic reviews were included. Additional references were identified from citations of published articles. FINDINGS: Niacin may reduce cardiovascular events as monotherapy; however, recent trials in combination with statins have failed to show a benefit. Trials with omega-3 FAs have failed to demonstrate significant reductions in cardiovascular outcomes. Fibrates may improve cardiovascular outcomes as monotherapy; however, trials in combination with statins have failed to show a benefit, except in those with elevated triglycerides (>200 mg/dL) or low HDL-C (<40 mg/dL). There is a lack of data that evaluates bile acid sequestrant in combination with statin therapy on reducing cardiovascular events. Ezetimibe-statin combination therapy can reduce cardiovascular outcomes in those with chronic kidney disease and following vascular surgery or acute coronary syndrome. Long-term effects of emerging nonstatin therapies (CETP and PCSK9 inhibitors) are currently being evaluated in ongoing Phase III trials. IMPLICATIONS: Nonstatin therapies have a limited role in reducing cardiovascular events in those maintained on guideline-directed statin therapy. In certain clinical situations, such as patients who are unable to tolerate statin therapy or recommended intensities of statin therapy, those with persistent severe elevations in triglycerides, or patients with high cardiovascular risk, some nonstatin therapies may be useful in reducing cardiovascular events. Future research is needed to evaluate the role of nonstatin therapies in those who are unable to tolerate guideline-directed statin doses.

Clofibrate in combination with phototherapy for unconjugated neonatal hyperbilirubinaemia.

BACKGROUND: There are many pathological conditions leading to an elevated unconjugated bilirubin level (hyperbilirubinaemia) in neonates. Currently the standard therapies for unconjugated hyperbilirubinaemia include phototherapy and exchange transfusion. In addition to phototherapy, clofibrate has been studied as a treatment for hyperbilirubinaemia in several countries. OBJECTIVES: To determine the efficacy and safety of clofibrate in combination with phototherapy versus phototherapy alone in unconjugated neonatal hyperbilirubinaemia. SEARCH METHODS: Randomised controlled trials were identified by searching MEDLINE (1950 to April 2012) before being translated for use in The Cochrane Library, EMBASE 1980 to April 2012 and CINAHL databases. All searches were re-run on 2 April 2012. SELECTION CRITERIA: We included trials where neonates with hyperbilirubinaemia received either clofibrate in combination with phototherapy or phototherapy alone or placebo in combination with phototherapy. DATA COLLECTION AND ANALYSIS: Data were extracted and analysed independently by two review authors (MG and HM). Treatment effects on the following outcomes were determined: mean change in bilirubin levels, mean duration of treatment with phototherapy, number of exchange transfusions needed, adverse effects of clofibrate, bilirubin encephalopathy and neonatal mortality. Study authors were contacted for additional information. Studies were analysed for methodological quality in a 'Risk of bias' table. MAIN RESULTS: Fifteen studies (two including preterm neonates and 13 including term neonates) were included in this review. All but one of the included studies were conducted in Iran. For preterm neonates, there was a significantly lower bilirubin level in the 100 mg/kg clofibrate group compared to the control group with a mean difference of -1.37 mg/dL (95% CI -2.19 mg/dL to -0.55 mg/dL) (-23 µmol/L; 95% CI -36 µmol/L to -9 µmol/L) after 48 hours. For the term neonates, there were significantly lower bilirubin levels in the clofibrate group compared to the control group after both 24 and 48 hours of treatment with a weighted mean difference of -2.14 mg/dL (95% CI -2.53 mg/dL to -1.75 mg/dL) (-37 µmol/L; 95% CI -43 µmol/L to -30 µmol/L] and -1.82 mg/dL (95% CI -2.25 mg/dL to -1.38 mg/dL) (-31 µmol/L; 95% CI -38 µmol/L to -24 µmol/L), respectively.There was a significantly lower duration of phototherapy in the clofibrate group compared to the control group for both preterm and term neonates with a weighted mean difference of -23.82 hours (95% CI -30.46 hours to -17.18 hours) and -25.40 hours (95% CI -28.94 hours to -21.86 hours), respectively.None of the studies reported on bilirubin encephalopathy rates, neonatal mortality rates, or the levels of parental or staff satisfactions with the interventions. AUTHORS' CONCLUSIONS: There are insufficient data from different countries on the use of clofibrate in combination with phototherapy for hyperbilirubinaemia to make recommendations for practice. There is a need for larger trials to determine how effective clofibrate is in reducing the need for, and duration of, phototherapy in term and preterm infants with hyperbilirubinaemia.

Novel use of a lipid-lowering fibrate medication to prevent nicotine reward and relapse: preclinical findings.

Experimental drugs that activate α-type peroxisome proliferator-activated receptors (PPARα) have recently been shown to reduce the rewarding effects of nicotine in animals, but these drugs have not been approved for human use. The fibrates are a class of PPARα-activating medications that are widely prescribed to improve lipid profiles and prevent cardiovascular disease, but these drugs have not been tested in animal models of nicotine reward. Here, we examine the effects of clofibrate, a representative of the fibrate class, on reward-related behavioral, electrophysiological, and neurochemical effects of nicotine in rats and squirrel monkeys. Clofibrate prevented the acquisition of nicotine-taking behavior in naive animals, substantially decreased nicotine taking in experienced animals, and counteracted the relapse-inducing effects of re-exposure to nicotine or nicotine-associated cues after a period of abstinence. In the central nervous system, clofibrate blocked nicotine's effects on neuronal firing in the ventral tegmental area and on dopamine release in the nucleus accumbens shell. All of these results suggest that fibrate medications might promote smoking cessation. The fact that fibrates are already approved for human use could expedite clinical trials and subsequent implementation of fibrates as a treatment for tobacco dependence, especially in smokers with abnormal lipid profiles.

Clofibrate for unconjugated hyperbilirubinemia in neonates: a systematic review.

OBJECTIVE: To evaluate the effect of clofibrate for unconjugated hyperbilirubinemia in neonates. METHODS: A systematic review with meta-analysis of randomized controlled trials or quasi-randomized controlled trials was conducted to evaluate the clofibrate treatment in neonates with unconjugated hyperbilirubinemia. We followed the guidelines from the Cochrane review group and the PRISMA statement. RESULTS: Of 148 studies identified, a total of 13 studies on 867 infants were included. A single oral administration of clofibrate was associated with decreased need of phototherapy (RR:.38, 95% CI: 0.21 to 0.68), shortened duration of phototherapy (mean duration: 23.88 h, 95% CI: 33.03 to -14.72 h) and reduced peak total serum bilirubin (mean duration: -1.62 mg/dL, 95% CI: 2.13 to -1.11 mg/dL). These effects were especially obvious in term infants and infants without hemolytic diseases. Data regarding mortality or kernicterus were not available from included studies. CONCLUSIONS: Clofibrate may have short-term benefits for the infants with hyperbilirubinaemia, especially for population of term infants and infants without hemolytic diseases. Large RCTs with long-term followup are required to verify the safety of clofibrate and assess its long-term effects.

The effect of clofibrate on hyperbilirubinemia of term neonates.

Clofibrate is a glucuronosyl transferase inducer that has been proposed to increase the elimination of bilirubin in neonates with hyperbilirubinemia. This study was conducted to determine the therapeutic effect of clofibrate in term neonates with non-hemolytic jaundice. This study was conducted on 52 newborns with pathologic unconjugated jaundice in Qazvin children hospital. Newborns divided randomly in two groups. Case group treated with clofibrate and intensive phototherapy, while control group treated only with intensive phototherapy. Serum bilirubin level was measured before and 6, 12, 24 and 48 hours after treatment. Results were compared and analyzed. The mean serum level of bilirubin before treatment in the case and control groups were 20.78 ± 2.38 and 20.52 ± 2.44 mg/dl, respectively (P=0.69). The mean serum level of bilirubin in 6, 12, 24 and 48 hours after treatment in the case group were 18.20 ± 2.20, 14.70 ± 2.06, 10.72 ± 2.40 and 8.90 ± 0.83 mg/dl , respectively. These values in control group were 18.26 ± 2.42, 15.36 ± 2.59, 12.29 ± 2.28 and 10.23 ± 1.50 mg/dl, respectively. There was significant difference between two groups regarding mean serum level of bilirubin 24 hours (P=0.019) and 48 hours after treatment (P=0.005). In conclusion, clofibrate was effective in reducing neonatal jaundice and its effect appeared 24 hours after treatment.

Mitochondrial HMG-CoA synthase partially contributes to antioxidant protection in the kidney of stroke-prone spontaneously hypertensive rats.

OBJECTIVE: Increased oxidative stress plays an important role in cardiovascular diseases including hypertension and stroke. Evidence has indicated that ketone bodies could exert antioxidative effects. We explored the role of renal mitochondrial 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMGCS2) expression, a key control site of ketogenesis, in stroke-prone spontaneously hypertensive rats (SHRSPs) and their ancestral hypertensive but stroke-resistant spontaneously hypertensive rats (SHRs). METHODS: Two groups of SHRSPs were fed a standard chow or standard chow supplemented with clofibrate (an agonist of HMGCS2 promoter), respectively, and SHRs fed with a standard chow were used as controls. The renal levels of HMGCS2, Akt, and phosphorylated protein kinase B (Akt) were measured by western blotting. Malondialdehyde, catalase, superoxide dismutase, and glutathione peroxidase were detected by assay kits. RESULTS: Compared with SHRs, lower HMGCS2 protein expression, enhanced phosphorylated Akt signal, higher malondialdehyde levels, and higher catalase activity were observed in kidney tissues in SHRSPs (P < 0.05). No differences in superoxide dismutase and glutathione peroxidase activities were observed between SHRSPs and SHRs. Clofibrate treatment significantly upregulated renal HMGCS2 expressions, inhibited phosphorylation of Akt, and decreased malondialdehyde levels and catalase activities in SHRSP kidney tissues (P < 0.05). CONCLUSION: These results demonstrated the difference in HMGCS2 expression and oxidative stress in kidney tissues between SHRSPs and their SHR controls. The enhanced oxidative stress was partly due to the lower HMGCS2 expression regulated possibly by the Akt signaling pathway.

The effect of clofibrate with phototherapy in late pre-term newborns with non-hemolytic jaundice.

BACKGROUND: Despite an understanding of the enzymatic pathways leading to bilirubin production and degradation, very few pharmacologic interventions are utilized and the mainstay of treatment remains phototherapy. AIMS: To evaluate the efficacy of clofibrate in reducing total serum bilirubin levels in late pre-term neonates with non-hemolytic jaundice. DESIGN AND SETTING: Double-blind, placebo-controlled, randomized trial; tertiary level neonatal unit. MATERIALS AND METHODS: A randomized controlled study was carried out in the neonatal ward of Children's Hospital, Tabriz, Iran, over a 1-year period. Sixty-eight healthy late pre-term infants readmitted with non-hemolytic hyperbilirubinemia were randomized to receive phototherapy and clofibrate (n= 35) or phototherapy and placebo (n= 33). STATISTICAL ANALYSIS USED: Chi-square test and independent sample 't' test. RESULTS: There were no significant differences in the weight, gender, modes of delivery and age of neonates between the two groups. Similarly the mean total serum bilirubin (TSB) level at the time of admission was not significantly different between the two groups [mean+/- SD: 19.72 +/- 1.79 (95% confidence interval: 19.12-20.54 mg/dL) vs. 20.05 +/- 2.82 (95% confidence interval, 19.54-22.04 mg/dL), P= 0.57]. The mean TSB 48 hours after phototherapy [mean+/- SD: 8.06+/- 1.34 (95% confidence interval: 7.94-10.18 mg/dL) vs.10.94 +/- 2.87 (95% confidence interval: 9.92-12.16 mg/dL), P= 0.02] and the mean duration of phototherapy [mean+/- SD: 64.32 +/- 12.48 (95% confidence interval: 60-81.6 hours) vs. 87.84 +/- 29.76 (95% confidence interval: 79.2-108 hours), P< 0.001] were significantly lower in the clofibrate-treated group. CONCLUSIONS: Clofibrate is an effective adjunctive drug in neonatal hyperbilirubinemia, which results in decreased TSB level and reduced duration of phototherapy in late pre-term newborns.

Efficacy of clofibrate on severe neonatal jaundice associated with glucose-6-phosphate dehydrogenase deficiency (a randomized clinical trial).

Glucose-6-phosphate dehydrogenase (G6PD) deficiency may cause severe hyperbilirubinemia with bilirubin encephalopathy unless intervention is initiated. The aim of this study was to assess the efficacy of clofibrate in full term G6PD deficient neonates with jaundice. A randomized clinical trial study was performed in two groups of full-term G6PD deficient jaundiced neonates (clofibrate treated group, n = 21; control group, n = 19). Infants in the clofibrate group received a single oral dose of 100 mg/kg clofibrate, whereas control group received nothing. Both groups were treated with phototherapy. Serum total and direct bilirubin levels were measured at the onset of treatments, 16, 24 and 48 hours later. On enrollment, the mean total serum bilirubin (TSB) level in the clofibrate treated group was 18.40 +/- 2.41 and in the control group was 17.49 +/- 1.03 (p = 0.401). At 16, 24 and 48 hours of treatment, the mean TSB in the clofibrate group were 15.2 +/- 1.9, 12.6 +/- 2.4, and 10.1 +/- 2.4 and in the control group were 16.5 +/- 1.2, 13.3 +/- 2.2 and 11.4 +/- 2.4, respectively (p = 0.047). At 48 hours, 7 (33%) cases in the clofibrate group and one (5%) case in the control group were discharged with a TSB < 10 mg/dl (p = 0.031). No side effects were observed on serial examinations during hospitalization, or on the 1st and 7th days after discharge. The results show that clofibrate induces a faster decline in serum total bilirubin level, a shorter duration of phototherapy, and hospitalization with no side effects in full-term G6PD deficient neonates with jaundice.

Effect of clofibrate in non-hemolytic indirect hyperbiliru-binemia in full term neonates.

OBJECTIVE: Jaundice is a common clinical problem in neonatal period which may result in brain damage even in healthy full term newborns, when it is severe. The aim of this study was to characterize the therapeutic effect of clofibrate in full term neonates who present with nonhemolytic jaundice. METHODS: A clinical controlled study was performed on 60 full term neonates who presented with non- hemolytic jaundice. 30 neonates were treated with a single oral dose of clofibrate (100 mg/Kg) plus phototherapy (case group), while 30 neonates received only phototherapy (control group). Both groups were compared in regard to post therapeutic mean total and indirect plasma bilirubin levels, admission duration and the rate of exchange transfusion. RESULTS: The reduction rate of total and indirect plasma bilirubin levels were significantly higher in the clofibrate- treated group as compared with the control group (P< 0.05). The mean duration of admission was found to be reduced from 2.9 +/- 0.9 days in the control groupl to 2.2 +/- 0.6 days in clofibrate- treated group (P=0.002). The mean plasma total bilirubin level was lower in the clofibrate- treated group. No cases required phototherapy after 48 hour in clofibrate- treated group, while 9 neonates (30%) and 2 neonates (6.7%) required phototherapy after 72 hour and 96 hour respectively in the control group. There was no difference between both the groups for sex, the time of developing jaundice and the rate of exchange transfusion. CONCLUSION: A single dose of clofibrate (100 mg/Kg) along with phototherapy is more effective than phototherapy alone in treating non-hemolytic hyperbilirubinemia in term healthy newborn infants.

Effect of clofibrate in jaundiced full-term infants:a randomized clinical trial.

BACKGROUND: Hyperbilirubinemia is a common problem in newborn infants. It can progress to kernicterus in severe forms, unless an intervention is initiated. The objective of this study was to determine the therapeutic effect of clofibrate in full-term neonates with nonhemolytic jaundice. METHODS: A randomized clinical trial was performed on two groups of full-term jaundiced neonates: the clofibrate-treated group (n = 30) and the control group (n = 30). Infants in the clofibrate group received a single oral dose of 100 mg/kg clofibrate while the neonates in the control group received distilled water (same color and volume); both groups received phototherapy. Serum total and direct bilirubin levels were measured at the beginning, 16, 24, 48, and 74 hours, after the start of the trial. RESULTS: The mean+/-SD total serum bilirubin level of the control and clofibrate groups at enrollment was 17.5+/-2.3 and 18.2+/-1.9 mg/dL, respectively (P = 0.199). The mean+/-SD total serum bilirubin in the control and clofibrate groups after 48 hours was 11.4+/-2.4 and 10.1+/-2.4 mg/dL, respectively (P = 0.047). After 72 hours of intervention, 25 (83%) neonates of the clofibrate group and 16 (53%) of the control group were discharged with a total serum bilirubin of <10 mg/dL (P = 0.026). No side-effect was observed on serial examination during hospitalization, and on the first and seventh day after discharge. CONCLUSION: Clofibrate results in a faster decline in TSB, shorter duration of hospitalization and had no side effects in jaundiced full-term neonates.

Anticholesterolemic effect of 3,4-di(OH)-phenylpropionic amides in high-cholesterol fed rats.

Two amide synthetic derivatives of 3,4-di(OH)-hydrocinnamate (HC), 3,4-dihydroxyphenylpropionic (l-serine methyl ester) amide (E030) and 3,4-dihydroxyphenylpropionic (l-aspartic acid) amide (E076), were investigated to compare their lipid-lowering efficacy with HC. Male rats were fed a 1 g/100 g high-cholesterol diet for 6 weeks with supplements of either clofibrate (0.02%, w/w), HC (0.025%, w/w), E030 (0.039%, w/w) or E076 (0.041%, w/w). The clofibrate supplement was used as a positive control for the lipid-lowering efficacy. The food intakes and body weight gains were not significantly different among the groups. The plasma and hepatic cholesterol and triglyceride levels were lower in clofibrate, HC, E030, and E076-supplemented groups compared to the control group. The supplementation of HC and its amide derivatives was as effective as clofibrate in increasing the ratio of HDL-cholesterol to total plasma cholesterol and reducing the atherogenic index (AI). The hepatic cholesterol level in the HC and E076 groups was significantly lower than that in the clofibrate group. The hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA reductase) and acyl-CoA:cholesterol acyltransferase (ACAT) activities were significantly lower in the all test groups than in the control group. The excretion of neutral sterol was significantly higher in the HC, E030, and E076-supplemented groups compared to the control group. The plasma AST and ALT activities, indirect indexes of hepatic toxicity, were significantly lower in the HC, E030, and E076-supplemented groups than in the control group. Accordingly, the current results suggest that E030 and E076, two amide synthetic derivatives of HC, are effective in lowering lipid activity.

Effect of clofibrate in jaundiced term newborns.

OBJECTIVE: Clofibrate is a glucuronosyl transferase inducer that has been proposed to increase the elimination of bilirubin in neonates with hyperbilirubinemia. The aim of this study was to characterize the therapeutic effect of clofibrate in neonates born at full term and present with non-hemolytic jaundice. METHODS: A clinical controlled study was performed in two groups of healthy full term neonates. Thirty neonates were treated with a single oral dose of clofibrate (100 mg/kg) plus phototherapy (clofibrate-treated group) while another 30 neonates (control group) received only phototherapy. RESULT: The mean plasma total bilirubin levels of 12th, 24th and 48th hours were significantly lower in the clofibrate-treated group as compared with the control group (P < 0.0001, P < 0.0001 and P = 0.004, respectively). Treatment with clofibrate also resulted in a shorter duration of jaundice and a decreased use of phototherapy (P < 0.0001). No side effects were observed. CONCLUSION: Although other pharmacological agents such as metalloporphyrins and Sn-mesoporphyrin also seem to be effective in decreasing bilirubin production, these products are not available for routine use and cannot be used because the safety of these drugs has to be confirmed prior to their widespread use. Therefore, clofibrate is now the only available pharmacological treatment of neonatal jaundice.

Pharmacological interventions for the treatment of neonatal jaundice.

In the neonate, hyperbilirubinaemia is usually due to a combination of an increased bilirubin load and decreased bilirubin elimination. Despite an understanding of the enzymatic pathways leading to bilirubin production and elimination, very few pharmacological interventions to prevent hyperbilirubinaemia are utilized and the mainstay of treatment remains phototherapy. Previously studied pharmacological agents such as D-penicillamine, phenobarbital and clofibrate may yet prove useful. Recent clinical trials using metalloporphyrins to inhibit heme catabolism and bilirubin production provides a novel pharmacological intervention for the treatment of neonatal jaundice. The safety and efficacy of these therapies will need to be confirmed prior to widespread use.

Choosing the right lipid-regulating agent. A guide to selection.

If dietary therapy and other lifestyle changes do not adequately normalise blood lipid levels, lipid-regulating drugs, as single-drug or combination-drug therapy, may be prescribed to supplement lifestyle changes. Evaluation of the individual patient's health and risk status, determination of the dyslipidaemia, definition of treatment goals and a clear understanding of the mechanisms and effects of lipid-regulating agents are necessary for optimisation of treatment. Although all the available lipid-regulating agents lower low density lipoprotein (LDL) cholesterol, the agents with the greatest LDL cholesterol-lowering effect are the bile acid sequestrants, which up-regulate the LDL receptor by the decrease in intrahepatic cholesterol caused by the interruption of enterohepatic circulation of cholesterol-rich bile acids, and the HMG-CoA reductase inhibitors, which partially inhibit HMG-CoA reductase. The agents with the greatest triglyceride-lowering effect are nicotinic acid, which decreases the production of very low density lipoprotein (VLDL) cholesterol and reduces the availability of free fatty acids in the circulation, and the fibric acid derivatives, which increase lipoprotein lipase activity and may also decrease the release of free fatty acids. Although the safety profile of the available lipid-regulating drugs has been established, patients should be monitored for potential adverse effects and interactions with concomitantly administered agents. When used correctly, lipid-regulating drug therapy is highly effective in the treatment of a variety of dyslipidaemias.

Protection against acetaminophen hepatotoxicity by a single dose of clofibrate: effects on selective protein arylation and glutathione depletion.

Previous reports demonstrated that repeated administration of peroxisome proliferators protects against acetaminophen (APAP) hepatotoxicity in mice. This protection was associated with a decrease in APAP's selective protein arylation and glutathione depletion. This study was conducted to determine if a single dose of clofibrate (CFB), rather than repeated doses, would similarly prevent APAP toxicity. CD-1 male mice received a single dose of 500 mg CFB/kg and controls were given corn oil 24 hr prior to APAP challenge. After an 18-hr fast, mice were challenged with 800 mg APAP/kg (in 50% propylene glycol) and killed at 4 or 12 hr. Other mice similarly pretreated were killed without APAP challenge. The results showed that pretreatment with a single CFB dose significantly decreased APAP-induced hepatotoxicity. At 12 hr after APAP plasma sorbitol dehydrogenase activity and the severity of hepatocellular necrosis were decreased in CFB pretreated mice. Surprisingly, no differences in hepatic nonprotein sulfhydryl (NPSH) depletion or selective arylation of target proteins in cytosol were observed at 4 hr after APAP challenge. Neither did a single dose of CFB significantly alter hepatic NPSH content prior to APAP challenge. These results indicate that protection against APAP hepatotoxicity by CFB does not require repeated administration, and the absence of significant alterations in APAP's selective protein arylation or glutathione depletion suggests that the protection against APAP hepatotoxicity after a single treatment with CFB may differ mechanistically from the protection observed after repeated CFB dosing.

Treatment of primary mixed hyperlipidemia with etophylline clofibrate: effects on lipoprotein-modifying enzymes, postprandial lipoprotein metabolism, and lipoprotein distribution and composition.

In 17 patients with primary mixed hyperlipidemia we studied levels and composition of lipoproteins in fasting plasma, lipoprotein-modifying enzymes, and postprandial lipoprotein metabolism after an oral fat-tolerance test supplemented with vitamin A before, and 12 weeks after treatment with etophylline clofibrate. With treatment, fasting plasma cholesterol, triglycerides, and the levels of very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), and low density lipoproteins (LDL) decreased significantly; high density lipoprotein (HDL) cholesterol increased significantly. Treatment caused also an increase in the protein content of IDL, a decrease in the triglyceride content of LDL, and an increase in the size of LDL as assessed by gradient gel electrophoresis. Concentrations of triglycerides, chylomicrons, and chylomicron remnants after an oral fat load supplemented with vitamin A decreased by 33%, 30% and 6%, respectively (P < 0.005; P < 0.01; and P < 0.05). The activity of lipoprotein lipase and hepatic lipase in postheparin plasma increased by 51% and 45%, respectively (P < 0.01; P < 0.05). We found a decrease in the mass concentration of cholesteryl ester transfer protein (P < 0.05). Stepwise multiple regression analysis showed that the triglyceride content of LDL is determined primarily by fasting triglycerides (r = + 0.53, P < 0.05;baseline) and cholesteryl ester transfer protein (r = + 0.49, P < 0.05; 12 weeks); in contrast, the triglyceride content of HDL3 is determined exclusively by accumulation of postprandial triglycerides (r = + 0.67; P < 0.05; baseline) and postprandial chylomicrons (r = +0.87; P < 0.005; 12 weeks). We conclude that hypolipidemic treatment with etophylline clofibrate favorably affects the cardiovascular risk factor profile in primary mixed hyperlipidemia.