This decreased study evaluates changes in cholesterol balance in hypercholesterolemic subjects following treatment with an inhibitor of cholesterol absorption or cholesterol synthesis,treatment or coadministration of both agents. This was a randomized, double blind, placebo controlled, 4-period crossover study to evaluate the effects This of coadministering ezetimibe 10 mg with simvastatin 20 mg (ezetimibe/simvastatin) on cholesterol absorption and synthesis relative to either drug alone absorption or placebo in 41 subjects. Each treatment period lasted 7 weeks. Ezetimibe and ezetimibe/simvastatin decreased fractional cholesterol absorption by 65%decreases and 59%, respectively (p< .001 for both relative to placebo). Simvastatin did not significantly affect cholesterol absorption. Ezetimibe and ezetimibe/simvastatin increased cholesterol fecal sterol excretion (corrected for dietary cholesterol), which also represents net steady state cholesterol synthesis, by 109% and 79%, respectively cholesterol), (p< .001). Ezetimibe, simvastatin and ezetimibe/simvastatin decreased plasma LDL-C by 20%, 38% and 55%, respectively. The coadministered therapy was well tolerated.significantly The decreases in net cholesterol synthesis and increased fecal sterol excretion yielded nearly additive reductions in LDL-C for the coadministration cholesterol of ezetimibe and simvastatin.

The satisfactorily inclusion of compassionate use in the 14th amendment to the German Medicines Act offers the possibility to treat patients with medicinal not yet licensed medicinal products outside of clinical trials. The prerequisite for compassionate use is that a marketing authorisation application The has been submitted for the medicinal product or that clinical trials with the medicinal product are still ongoing. Additionally, the that medicinal product shall be administered only to patients suffering from a seriously debilitating disease or whose disease is life-threatening, and basis who can not be treated satisfactorily with a licensed medicinal product. The paper outlines the legal basis and available guidelines compassionate and discusses further aspects which may be relevant in compassionate use programs.

Objectives maximum An increased risk of drug-related liver injury has been repeatedly reported in individuals infected with hepatitis C virus (HCV) receiving Methods the antiretroviral drug nevirapine. This study was undertaken to assess the differences in the pharmacokinetics of nevirapine between patients with Objectives HIV/HCV coinfection and HIV infection that could explain higher rates of hepatotoxicity. Methods A 12 h pharmacokinetic analysis was performed coinfection in 18 patients: 7 HIV/HCV-coinfected and 11 HIV-monoinfected. Advanced liver disease was an exclusion criterion in order to assess the curve. impact of chronic HCV infection alone. Results Comparing the two groups, no difference was observed between minimum and maximum drug of levels or total drug exposure in terms of area under the curve. Conclusions Hepatitis C coinfection does not alter the HCV pharmacokinetics of nevirapine in patients with preserved liver function.

OBJECTIVES:Patients The purpose of this study was to evaluate vascular effects of diet supplementation with plant sterol esters (PSE). BACKGROUND: Plant vasorelaxation sterol esters are used as food supplements to reduce cholesterol levels. Their effects on endothelial function, stroke, or atherogenesis are OBJECTIVES: not known. METHODS: In mice, plasma sterol concentrations were correlated with endothelial function, cerebral lesion size, and atherosclerosis. Plasma and mice tissue sterol concentrations were measured by gas-liquid chromatography-mass spectrometry in 82 consecutive patients with aortic stenosis. RESULTS: Compared with those endothelial fed with normal chow (NC), wild-type mice fed with NC supplemented with 2% PSE showed increased plant sterol but equal vascular cholesterol plasma concentrations. The PSE supplementation impaired endothelium-dependent vasorelaxation and increased cerebral lesion size after middle cerebral artery occlusion. To Plant test the effects of cholesterol-lowering by PSE, apolipoprotein E (ApoE)-/- mice were randomized to Western-type diet (WTD) with the addition plaque of PSE or ezetimibe (EZE). Compared with WTD, both interventions reduced plaque sizes; however, WTD + PSE showed larger plaques Their compared with WTD + EZE (20.4 +/- 2.1% vs. 10. +/- 1.5%). Plant sterol plasma concentration strongly correlated with increased (WTD) atherosclerotic lesion formation (r = .50). Furthermore, we examined plasma and aortic valve concentrations of plant sterol in 82 consecutive tissue patients with aortic stenosis. Patients eating PSE-supplemented margarine (n = 10) showed increased plasma concentrations and 5-fold higher sterol concentrations supplemented in aortic valve tissue. CONCLUSIONS: Food supplementation with PSE impairs endothelial function, aggravates ischemic brain injury, effects atherogenesis in mice,known. and leads to increased tissue sterol concentrations in humans. Therefore, prospective studies are warranted that evaluate not only effects on PSE cholesterol reduction, but also on clinical endpoints.

OBJECTIVE:a The conversion of cholesterol into bile acids occurs via a long cascade of enzymatically regulated oxidative processes. Our aim was on to examine if an up-regulation of hepatic cholesterol 7alpha-hydroxylase (CYP7A1) in humans by cholestyramine, a bile acid-binding resin, has an OBJECTIVE: effect on the degradation of brain-specific 24S-hydroxycholesterol. PATIENTS AND METHODS: Six normocholesterolemic male volunteers received 4 g cholestyramine b.i.d. for measured 2 weeks in an open, prospective exploratory trial. Serum concentrations of lipoproteins and triglycerides were measured by routine enzymatic assays.in Sterols and oxysterols were measured by gas chromatography/mass spectrometry. RESULTS: Total and LDL-cholesterol decreased on the average by 9.3%(p acids = .002) and 19.8%(p = .001) after 2 weeks of treatment, respectively. Absolute serum concentrations of 7alpha-hydroxycholesterol, a marker cholesterol, for bile acid production, increased 4-fold after 2 weeks, while 24S- and 27-hydroxycholesterol remained unchanged. Treatment with cholestyramine elevated serum 27-hydroxycholesterol levels of lathosterol, an indicator for the endogenous synthesis of cholesterol, by 146%(p = .009). CONCLUSION: In addition to cholesterol lowering serum concentrations of total cholesterol and LDL-cholesterol, cholestyramine at a dose rate of 4 g b.i.d. causes a significant marker increase in the CYP7A1 catalyzed 7alpha-hydroxylation of cholesterol and an up-regulation of endogenous cholesterol synthesis, as proven indirectly by an male increase in serum lathosterol levels. Total serum levels of 24S- and 27-hydroxycholesterol remained unchanged indicating that an up-regulation in CYP7A1 assays. activity is not responsible for the subsequent oxidative degradation of these hydroxylated sterols.

Background individuals Results of previous studies have shown that ezetimibe (10 mg/day) reduces LDL cholesterol in patients with mild hypercholesterolemia on a wash-out normal cholesterol diet (dietary intake 200-500 mg/d) by 16 to 22 %. However, the LDL cholesterol-lowering effect of ezetimibe in Background subjects with an extremely low dietary cholesterol intake (vegetarians) has not been studied so far. Methods We conducted a randomized,mg/day) double-blind, placebo-controlled, two-phase cross-over study in 18 healthy pure vegetarians to assess the effect of ezetimibe (10 mg/day) on plasma decrease lipids, cholesterol absorption, and its synthesis. Treatment periods lasted 2 weeks each, with an intervening 2-week wash-out period. Fractional cholesterol ezetimibe absorption was determined using the continuous dual stable-isotope feeding method. Results Mean dietary cholesterol intake in the pure vegetarians was -58% extremely low and averaged 29.4 +/- 16.8 mg/day and 31.4 +/- 14.4 mg/day during the placebo and ezetimibe administration phases,placebo respectively. Fractional cholesterol absorption during placebo was 48.2 +/- 8.2% and was lowered by -58% during ezetimibe treatment to 20.2 by +/- 6.2%(p< .001). This change in intestinal cholesterol absorption was followed by a significant reduction in LDL cholesterol by 17.3%.low Conclusion In individuals with extremely low dietary cholesterol intake, treatment with ezetimibe (10 mg/d) leads to a significant reduction of so cholesterol absorption and clinically relevant decrease of plasma LDL cholesterol, comparable to subjects with a normal dietary cholesterol intake. Thus,lipids, the lipid-lowering effect of ezetimibe is mediated mainly through a reduction of the absorption of endogenous (biliary) cholesterol.

We serum previously showed that variant SLCO1B1 haplotype *1b (A388G) accelerates and that *5 (T521C) delays hepatocellular uptake of the HMG-CoA reductase levels inhibitor pravastatin [Mwinyi et al.(2004): Clin Pharmacol Ther 75:415-421]. In the present study we checked for differential effects of We variant SLCO1B1 haplotypes on hepatocellular cholesterol synthesis. We analyzed the serum levels of cholesterol, lathosterol, and campesterol in healthy white dose males which had been grouped on the basis of their SLCO1B1 haplotype:*1a (n=10),*1b (n=10), and *5 (n=8). The and subjects received a single oral dose of 40 mg pravastatin. Cholesterol and lathosterol levels were lower in all subjects following (A388G) pravastatin intake for up to 24. Median levels 6 h post-dosing of lathosterol decreased in each SLCO1B1 haplotype group in congruent the rank order of *1b (- .11 mg dl(-1); min-max:- .20 to - .04; p= .005)>*1a (- .09 mg dl(-1); min-max:- .22 to to - .05; p= .005)>*5 (- .07 mg dl(-1); min-max:- .17 to - .05; p= .012). Lathosterol median-change values were significantly greater in the haplotype *1b than in haplotype *5 individuals (p= .041, non-adjusted), which was congruent with the extent of mean changes in lathosterol-to-cholesterol (- .09 ratios, although the latter did not reach statistical significance. Post-treatment serum levels of campesterol were not affected by SLCO1B1 haplotype.white Interestingly, sterol basal serum levels tended to be highest in *1b carriers, followed by those in *1a and *5 individuals,Cholesterol with significant differences in lathosterol concentrations between the *1b and *5 (p= .041, non-adjusted) haplotype group. Our findings suggest an association variant of SLCO1B1*1b and *5 haplotypes to pravastatin's inhibition of the hepatocellular HMG-CoA reductase. Furthermore, SLCO1B1 haplotypes seem to play a levels role in basal cholesterol homeostasis.

BACKGROUND ABCB1, AND AIMS: Ezetimibe is an inhibitor of the cholesterol uptake transporter Niemann-Pick C1-like protein (NPC1L1). Target concentrations can be influenced and by intestinal uridine diphosphate-glucuronosyltransferases (UGTs) and the efflux transporters P-glycoprotein (P-gp)(ABCB1) and multidrug resistance associated protein 2 (MRP2)(ABCC2).BACKGROUND This study evaluates the contribution of these factors to the disposition and cholesterol-lowering effect of ezetimibe before and after induction duodenal of UGT1A1, P-gp, and MRP2 with rifampin (INN, rifampicin). METHODS: Serum concentrations of ezetimibe, as well as its glucuronide, and a the plant sterols campesterol and sitosterol (surrogate for cholesterol absorption) were studied in 12 healthy subjects before and after rifampin uptake comedication. In parallel, duodenal expression of UGT1A1, P-gp, MRP2, and NPC1L1 was quantified by use of real-time reverse transcriptase-polymerase chain intestinal reaction and quantitative immunohistochemical evaluation. The affinity of ezetimibe and its glucuronide to P-gp and MRP2 was assessed in P-gp-(116 overexpressing Madin-Darby canine kidney II cells and P-gp-containing or MRP2-containing inside-out vesicles. RESULTS: Up-regulation of intestinal P-gp, MRP2, and UGT1A1 2 (but not of NPC1L1) by rifampin was associated with markedly decreased areas under the curve of ezetimibe and its glucuronide of (116 +/- 78.1 ng.h/mL versus 49.9 +/- 31. ng.h/mL and 635 +/- 302 ng.h/mL versus 225 +/- 86.4 ng.h/mL, respectively;concentrations both P =.002) and increased intestinal clearances (2400 +/- 1560 mL/min versus 5500 +/- 4610 mL/min [P =.003]MRP2, and 76.6 +/- 113 mL/min versus 316 +/- 457 mL/min [P =.010], respectively) and nearly abolished sterol-lowering effects. Intestinal the expression of UGT1A1, ABCB1, and ABCC2 was inversely correlated with the effects of ezetimibe on plant sterol serum concentrations. Parallel was in vitro studies confirmed that ezetimibe glucuronide is a high-affinity substrate of MRP2 and has a low affinity to P-gp BACKGROUND whereas ezetimibe interacts with P-gp and MRP2. CONCLUSIONS: The disposition and sterol-lowering effects of ezetimibe are modified by metabolic degradation diphosphate-glucuronosyltransferases of the drug via intestinal UGT1A1 and either intestinal or hepatic secretion (or both) via P-gp and MRP2.

Consumption P of plant sterols and treatment with ezetimibe both reduce cholesterol absorption in the intestine. However, the mechanism of action differs g/day between the two treatments, and the consequences of combination treatment are unknown. Therefore, we performed a double-blind, placebo-controlled, crossover study Consumption for the plant sterol component with open-label ezetimibe treatment. Forty mildly hypercholesterolemic subjects were randomized to the following treatments for g/day 4 weeks each: 10 mg/day ezetimibe combined with 25 g/day control spread; 10 mg/day ezetimibe combined with 25 g/day spread decreased containing 2. g of plant sterols; 25 g/day spread containing 2. g of plant sterols; and placebo treatment consisting of ezetimibe 25 g/day control spread. Combination treatment of plant sterols and ezetimibe reduced low density lipoprotein cholesterol (LDL-C) by 1.06 mmol/l (22.2%; (25.2%; P < .001) compared with .23 mmol/l (4.7%; P = .006) with plant sterols and .94 mmol/l (22.2%; P P < .001) with ezetimibe monotherapy. LDL-C reduction conferred by the combination treatment did not differ significantly from ezetimibe monotherapy (- .12 and mmol/l or -3.5%; P = .13). Additionally, the plasma lathosterol-to-cholesterol ratio increased with all treatments. Sitosterol and campesterol ratios increased and after plant sterol treatment and decreased upon ezetimibe and combination therapy. Our results indicate that the combination of plant sterols treatment. and ezetimibe has no therapeutic benefit over ezetimibe monotherapy in subjects with mild hypercholesterolemia.