Biomedical subjects

Stephen E Maxwell

Publications and source records attributed to Stephen E Maxwell.

6 recordsLinked to original sources

PubMed2006

Interaction of single-dose ezetimibe and steady-state cyclosporine in renal transplant patients.

This open-label, single-period study evaluated the single-dose pharmacokinetics of ezetimibe (EZE) 10 mg in the setting of steady-state cyclosporine (CyA) dosing in renal transplant patients. A single 10-mg dose of EZE was coadministered with the morning dose of CyA (75-150 mg twice a day). Total EZE (sum of unconjugated, parent EZE and EZE-glucuronide; EZE-total) AUC(0-last) and Cmax were compared to values derived from a prespecified database of healthy volunteers. Geometric mean ratios (90% CIs) for (EZE + CyA)/EZE alone for EZE-total AUC((0-last)) and Cmax were 3.41 (2.55, 4.56) and 3.91 (3.13, 4.89), respectively. Compared to healthy controls, EZE-total AUC((0-last)) was 3.4-fold higher in transplant patients receiving CyA; similar exposure levels were seen in a prior multiple-dose study in which EZE 50 mg was administered to healthy volunteers without dose-related toxicity. Because the long-term safety implications of both higher EZE exposures and undetermined effect on CyA are not yet understood, the clinical significance of this interaction is unknown.

Adult↗

PubMed2004

Pharmacodynamic and pharmacokinetic interaction between fenofibrate and ezetimibe.

OBJECTIVE: The cholesterol absorption inhibitor, ezetimibe, significantly decreases low-density lipoprotein-cholesterol (LDL-C) levels in patients with primary hypercholesterolemia. The pharmacodynamic, pharmacokinetic, and safety profiles of ezetimibe and fenofibrate were evaluated alone and after co-administration in 32 subjects with primary hypercholesterolemia. RESEARCH DESIGN AND METHODS: This was a randomized, evaluator (single)-blind, placebo-controlled, parallel-group study. Subjects with untreated LDL-C > or = 130 mg/dL (3.37 mmol/L) were randomized to receive one of four oral treatments each morning for 14 days: fenofibrate 200 mg + ezetimibe 10 mg, fenofibrate 200 mg, ezetimibe 10 mg, or placebo. Serum lipids were assessed before drug administration on day 1, day 7, and day 14. Pharmacokinetic parameters were assessed on day 14. MAIN OUTCOME MEASURES: The primary pharmacodynamic parameter was percentage change from baseline in LDL-C concentration following co-administration of ezetimibe and fenofibrate vs either drug alone, or placebo. A secondary outcome was the potential for a pharmacokinetic interaction between ezetimibe and fenofibrate. RESULTS: Ezetimibe and fenofibrate co-administration was well tolerated and produced statistically significant mean percentage reductions from baseline in LDL-C (p < or = 0.05 vs either drug alone or placebo), total cholesterol and triglycerides (p < or = 0.05 vs either fenofibrate or placebo), apolipoprotein C-III (p < or = 0.05 vs placebo), and LDL-III (p < or = 0.05 vs either drug alone or placebo). Ezetimibe did not significantly affect the pharmacokinetics of fenofibrate. Concomitant fenofibrate administration significantly increased the mean C(max) and AUC of total ezetimibe approximately 64% and 48%, respectively. However, based on the established safety profile and flat dose-response of ezetimibe, this effect is not considered to be clinically significant. CONCLUSION: Co-administration of ezetimibe and fenofibrate produced significantly greater reductions in LDL-C than either drug alone and greater reductions in triglycerides than fenofibrate. These effects were accompanied by improvements in the lipid/lipoprotein profile, suggesting that co-administration therapy with ezetimibe and fenofibrate may be an effective therapeutic option for patients with mixed dyslipidemia.

Adult↗

PubMed2004

Effects of ezetimibe on the pharmacodynamics and pharmacokinetics of lovastatin.

BACKGROUND: Ezetimibe is a cholesterol absorption inhibitor which decreases low-density lipoprotein cholesterol (LDL-C) in patients with hypercholesterolemia. This study investigated the potential for pharmacodynamic and/or pharmacokinetic interactions between ezetimibe and lovastatin. METHODS: In a randomized, evaluator (single)-blind, placebo-controlled, parallel-group study, 48 healthy men with hypercholesterolemia (screening LDL-C >or= 130 mg/dL) who were stabilized and maintained on a National Cholesterol Education Program (NCEP) Step I diet were randomized to one of the following six oral treatments once daily for 14 days: lovastatin 20 mg; lovastatin 20 mg plus ezetimibe 5, 10, or 20 mg; lovastatin 40 mg plus ezetimibe 10mg; or placebo. RESULTS: Reported adverse events were generally mild, nonspecific, and similar among treatments. There were no significant changes in safety laboratory test results, including those for enzymes indicative of muscle or liver injury. Coadministration of ezetimibe and lovastatin did not increase the plasma concentrations of lovastatin or beta-hydroxylovastatin. In this parallel comparison study there was an apparent decrease in lovastatin exposure, however, the reduction in lovastatin or beta-hydroxylovastatin concentrations was not related to the ezetimibe dose and is not considered to be clinically important. Ezetimibe 5, 10, or 20 mg combined with lovastatin 20 mg caused a significantly (p < 0.01) greater reduction in LDL-C than lovastatin 20 mg alone, with no apparent effect on HDL-C or triglycerides. LDL-C was reduced by 51.0% with ezetimibe 10 mg plus lovastatin 20 mg, 56.0% with ezetimibe 10 mg plus lovastatin 40 mg, 33.2% with lovastatin alone, and 17.3% with placebo. CONCLUSIONS: The co-administration of ezetimibe and lovastatin was well tolerated and resulted in a significantly greater percentage reduction in serum LDL-C concentrations than with lovastatin alone, with an average incremental reduction of 16-18%. Ezetimibe 10mg appears to be the optimal dose when co-administered with lovastatin 20mg once daily. Further incremental reductions in LDL-C from the co-administration of ezetimibe and lovastatin are expected only when the dose of lovastatin is increased. The co-administration of ezetimibe and lovastatin has the potential to produce clinically significant reductions in LDL-C compared to either drug alone, with favorable safety and tolerability.

Adult↗

PubMed2004

Pharmacodynamic interaction between ezetimibe and rosuvastatin.

BACKGROUND: Ezetimibe is a lipid-lowering drug indicated for the treatment of hypercholesterolemia as co-administration with HMG-CoA reductase inhibitors (statins) or as monotherapy. The primary objectives of this study were to evaluate the pharmacodynamic effects and safety of the co-administration of ezetimibe and the new statin rosuvastatin. A secondary objective was to examine the potential for a pharmacokinetic interaction between ezetimibe and rosuvastatin. METHODS: This was a randomized, evaluator (single)-blind, placebo-controlled, parallel-group study in healthy hypercholesterolemic subjects (untreated low-density lipoprotein cholesterol [LDL-C] > or = 130 mg/dL [3.37 mmol/L]). After the outpatient screening and NCEP Step I diet stabilization periods, 40 subjects were randomized to one of the 4 following treatments: rosuvastatin 10 mg plus ezetimibe 10 mg (n = 12); rosuvastatin 10 mg plus placebo (matching ezetimibe 10 mg) (n = 12); ezetimibe 10 mg plus placebo (matching ezetimibe 10 mg) (n = 8); or placebo (2 tablets, matching ezetimibe 10 mg) (n = 8). All study treatments were administered once daily in the morning for 14 days as part of a 16-day inpatient confinement period. Fasting serum lipids were assessed pre-dose on days 1 (baseline), 7, and 14 by direct quantitative assay methods. Safety was evaluated by monitoring laboratory tests and recording adverse events. Blood samples were collected for ezetimibe and rosuvastatin pharmacokinetic evaluation prior to the first and last dose and at frequent intervals after the last dose (day 14) of study treatment. Plasma ezetimibe, total ezetimibe (ezetimibe plus ezetimibe-glucuronide) and rosuvastatin concentrations were determined by validated liquid chromatography with tandem mass spectrometric detection (LC-MS/MS) assay methods. RESULTS: All active treatments caused statistically significant (p < or = 0.02) decreases in LDL-C concentration versus placebo from baseline to day 14. The co-administration of ezetimibe and rosuvastatin caused a significantly (p < 0.01) greater reduction in LDL-C and total cholesterol than either drug alone. In this 2-week inpatient study with restricted physical activity there was no apparent effect of any treatment on high-density lipoprotein cholesterol (HDL-C) or triglycerides. The co-administration of ezetimibe and rosuvastatin caused a significantly (p < 0.01) greater percentage reduction in mean LDL-C (-61.4%) than rosuvastatin alone (-44.9%), with a mean incremental reduction of -16.4% (95%CI -26.3 to -6.53). Reported side effects were generally mild, nonspecific, and similar among treatment groups. There were no significant increases or changes in clinical laboratory tests, particularly those assessing muscle and liver function. There was no significant pharmacokinetic drug interaction between ezetimibe and rosuvastatin. CONCLUSIONS: Co-administration of ezetimibe 10 mg with rosuvastatin 10 mg daily caused a significant incremental reduction in LDL-C compared with rosuvastatin alone. Moreover, co-administering ezetimibe and rosuvastatin was well tolerated in patients with hypercholesterolemia.

Adult↗

PubMed2002

Pharmacodynamic interaction between the new selective cholesterol absorption inhibitor ezetimibe and simvastatin.

AIMS: The primary aims of these two single-centre, randomized, evaluator-blind, placebo/positive-controlled, parallel-group studies were to evaluate the potential for pharmacodynamic and pharmacokinetic interaction between ezetimibe 0.25, 1, or 10 mg and simvastatin 10 mg (Study 1), and a pharmacodynamic interaction between ezetimibe 10 mg and simvastatin 20 mg (Study 2). Evaluation of the tolerance of the coadministration of ezetimibe and simvastatin was a secondary objective. METHODS: Eighty-two healthy men with low-density lipoprotein cholesterol (LDL-C) >or=130 mg dl-1 received study drug once daily in the morning for 14 days. In Study 1 (n=58), five groups of 11-12 subjects received simvastatin 10 mg alone, or with ezetimibe 0.25, 1, or 10 mg or placebo. In Study 2 (n=24), three groups of eight subjects received simvastatin 20 mg alone, ezetimibe 10 mg alone, or the combination. Blood samples were collected to measure serum lipids in both studies. Steady-state pharmacokinetics of simvastatin and its beta-hydroxy metabolite were evaluated in Study 1 only. RESULTS: In both studies, reported side-effects were generally mild, nonspecific, and similar among treatment groups. In Study 1, there were no indications of pharmacokinetic interactions between simvastatin and ezetimibe. All active treatments caused statistically significant (P<0.01) decreases in LDL-C concentration vs placebo from baseline to day 14. The coadministration of ezetimibe and simvastatin caused a dose-dependent reduction in LDL-C and total cholesterol, with no apparent effect on high-density lipoprotein cholesterol (HDL-C) or triglycerides. The coadministration of ezetimibe 10 mg and simvastatin 10 mg or 20 mg caused a statistically (P<0.01) greater percentage reduction (mean -17%, 95% CI -27.7, -6.2, and -18%, -28.4, -7.4, respectively) in LDL-C than simvastatin alone. CONCLUSIONS: The coadministration of ezetimibe at doses up to 10 mg with simvastatin 10 or 20 mg daily was well tolerated and caused a significant additive reduction in LDL-C compared with simvastatin alone. Additional clinical studies to assess the efficacy and safety of coadministration of ezetimibe and simvastatin are warranted.

Administration, Oral↗

PubMed2002

Disposition of the selective cholesterol absorption inhibitor ezetimibe in healthy male subjects.

Ezetimibe [SCH 58235; 1-(4-fluorophenyl)-3(R)-[3-(4-fluorophenyl)-3(S)-hydroxypropyl]-4(S)-(4-hydroxyphenyl)-2-azetidinone], a selective cholesterol absorption inhibitor, is being developed for the treatment of primary hypercholesterolemia. The absorption, metabolism, and excretion of ezetimibe were characterized in eight healthy male volunteers in this single-center, single-dose, open-label study. Subjects received a single oral 20-mg dose of [14C]ezetimibe (approximately 100 microCi) with 200 ml of noncarbonated water after a 10-h fast. Concentrations of radioactivity and/or ezetimibe (conjugated and unconjugated) were determined in plasma, urine, and fecal samples. Ezetimibe was rapidly absorbed and extensively conjugated following oral administration. The main circulating metabolite in plasma was SCH 60663 [1-O-[4-[trans-(2S,3R)-1-(4-fluorophenyl)-4-oxo-3-[3(S)-hydroxy-3-(4-fluorophenyl)propyl]-2-azetidinyl]phenyl]-beta-D-glucuronic acid], the glucuronide conjugate of ezetimibe. Plasma concentration-time profiles of unconjugated and conjugated drug exhibited multiple peaks, indicating enterohepatic recycling. Approximately 78 and 11% of the administered [14C]ezetimibe dose were excreted in feces and urine, respectively, by 240 h after drug administration. Total recovery of radioactivity averaged 89% of the administered dose. The main excreted metabolite was the glucuronide conjugate of ezetimibe. The primary metabolite in urine (0- to72-h composite) was also the glucuronide conjugate (about 9% of the administered dose). Significant amounts (69% of the dose) of ezetimibe were present in the feces, presumably as a result of SCH 60663 hydrolysis and/or unabsorbed drug. No adverse events were reported in this study. A single 20-mg capsule of [(14)C]ezetimibe was safe and well tolerated after oral administration. The pharmacokinetics of ezetimibe are consistent with extensive glucuronidation and enterohepatic recirculation. The primary metabolic pathway for ezetimibe is by glucuronidation of the 4-hydroxyphenyl group.

Adult↗