Home About us Contact
|
Home About us Contact | ||
|
|
||
Three-way Crossover Study (three-way + crossover_study)
Selected AbstractsA 75% insulin lispro/25% NPL mixture provides a longer duration of insulin activity compared with insulin lispro alone in patients with Type 1 diabetesDIABETIC MEDICINE, Issue 11 2003P. Roach Abstract Aims To compare a new insulin formulation, high mix (HM) [75% lispro (LP) and 25% neutral protamine lispro (NPL)], to regular human insulin (HR) and LP with respect to glucose response and pharmacokinetics following a test meal in patients with Type 1 diabetes. Methods After fasting overnight, patients received an intravenous insulin infusion to standardize blood glucose (BG) to 7.5 mmol/l (135 mg/dl). In a randomised, three-way crossover study, HR was injected 30 min before, and LP or HM was injected immediately before the test meal on three separate occasions. For each patient, LP and HR were administered at identical doses; the HM dose was one and one third times that of HR and LP to maintain the same dose of short or rapid-acting insulin. The insulin infusion was stopped 15 min after the insulin injection. Free insulin and BG concentrations were measured frequently for 7 h following the test meal. Results HM and LP resulted in better glycaemic control than HR during the observation period. BG concentrations during the first 4,5 h did not differ between HM and LP. However, HM exhibited prolonged insulin activity relative to LP beyond 5 h, extending the duration of action by approximately 1 h, and resulting in lower overall BG concentrations when the 0,6- and 0,7-h intervals were considered. Conclusions Compared with LP, HM provided similar glycaemic control for up to 5 h and superior glycaemic control from 5 to 7 h following a standard test meal [source] B-domain deleted recombinant factor VIII preparations are bioequivalent to a monoclonal antibody purified plasma-derived factor VIII concentrate: a randomized, three-way crossover studyHAEMOPHILIA, Issue 2 2005C. M. Kessler Summary., Background:, Deletion of the B-domain of recombinant blood coagulation factor VIII (BDDrFVIII) increases the manufacturing yield of the product but does not impair in vitro or in vivo functionality. BDDrFVIII (ReFacto®) has been developed with the additional benefit of being formulated without human albumin. Objective:, The primary objective of this three-way crossover-design study was to compare the pharmacokinetic (PK) parameters of two BDDrFVIII formulations (one reconstituted with 5 mL of sterile water, the other reconstituted with 4 mL sodium chloride 0.9% USP) with those of a plasma-derived, full-length FVIII preparation (Hemofil® M) in patients with haemophilia A to determine bioequivalence. Methods:, A series of blood samples were collected over a period of 48 h after i.v. administration of each of the FVIII preparations. Plasma FVIII activity was determined using a validated chromogenic substrate assay. Plasma FVIII activity vs. time curves was characterized for a standard set of PK parameter estimates. Two parameter estimates, the maximum plasma concentration (Cmax) and the area under plasma concentration vs. time curves (AUCs), were used to evaluate bioequivalence. The two preparations were considered bioequivalent if the 90% confidence intervals for the ratio of geometric means for Cmax and AUCs fell within the bioequivalence window of 80% to 125%. Results/Conclusion:, Results show that each BDDrFVIII formulation is bioequivalent to Hemofil M and the two formulations of BDDrFVIII are bioequivalent to each other. [source] Lack of effects between rupatadine 10,mg and placebo on actual driving performance of healthy volunteersHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2007Eric Vuurman Abstract Introduction Rupatadine fumarate is a potent, selective, histamine H1 -receptor antagonist and PAF inhibitor with demonstrated efficacy for the relief of allergic rhinitis. Rupatadine does not easily cross the blood,brain barrier and is believed to be non-sedating at therapeutic doses. Consequently, rupatadine should show no impairment on car driving. Objective This study compared the acute effects of rupatadine, relative to placebo and hydroxyzine (as an active control), on healthy subjects' driving performance. Methods Twenty subjects received a single dose of rupatadine 10,mg, hydroxyzine 50,mg, or placebo in each period of this randomized, double-blind, three-way crossover study. Two hours postdosing, subjects operated a specially instrumented vehicle in tests designed to measure their driving ability. Before and after the driving tests ratings of sedation were recorded. Results There was no significant difference between rupatadine and placebo in the primary outcome variable: standard deviation of lateral position (SDLP); however, hydroxyzine treatment significantly increased SDLP (p,<,0.001 for both comparisons). Objective (Stanford sleepiness scale) and subjective sedation ratings (Visual Analogue Scales) showed similar results: subjects reported negative effects after hydroxyzine but not after rupatadine. Conclusion Rupatadine 10,mg is not sedating and does not impair driving performance. Copyright © 2007 John Wiley & Sons, Ltd. [source] Mirtazapine and paroxetine: a drug-drug interaction study in healthy subjectsHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 6 2001F. J. L. Ruwe Abstract Paroxetine inhibits cytochrome P450 2D6, which is involved in the metabolism of mirtazapine. The possible drug-drug interaction between two pharmacologically distinct antidepressants, mirtazapine and paroxetine, has been investigated in a randomized, three-way crossover study in 24 healthy male and female subjects. After a titration phase of 3 days, each subject received single daily doses of 30,mg mirtazapine, 40,mg paroxetine or the combination for 6 days. Assessments included serial blood sampling for pharmacokinetics at steady state, cognitive testing using the test battery of CDR Ltd, a visual analogue mood rating scale (Bond and Lader) and the Leeds Sleep Evaluation Questionnaire. Paroxetine inhibits the metabolism of mirtazapine, as shown by increases of approximately 17% and 25% of the 24,h AUC's of mirtazapine and its demethyl metabolite, respectively. Mirtazapine did not alter the pharmacokinetics of paroxetine. The combined administration of mirtazapine and paroxetine probably does not alter cognitive functioning or result in major changes on the visual analogue mood rating scale and Sleep Evaluation Questionnaire, compared with the administration of either drug alone. The incidence of adverse events was lower during combined administration of mirtazapine and paroxetine than during administration of either drug alone. Fatigue, dizziness, headache, nausea, anxiety and somnolence were the most common adverse events during combined administration. These data suggest that the combination of mirtazapine and paroxetine is unlikely to lead to clinically relevant drug-drug interactions and can be used without dose adjustment of either drug. The combination may even be better tolerated than either drug alone. Copyright © 2001 John Wiley & Sons, Ltd. [source] Comparison of the effects of fasting morning, fasting evening and fed bedtime administration of tenatoprazole on intragastric pH in healthy volunteers: a randomized three-way crossover studyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2006A. B. R. THOMSON Background, The effectiveness of proton pump inhibitors is influenced by meals and administration time. Aim, To compare the effects on intragastric acidity of times of dosing of tenatoprazole, a novel imidazopyridine-based proton pump inhibitor with a prolonged plasma half-life. Methods, This randomized three-period crossover study included 12 Helicobacter pylori -negative healthy subjects, who received tenatoprazole 40 mg either fasting at 7.00 am, fasting at 7.00 pm or fed at 9.30 pm for 7 days, with a 2-week washout between periods. Twenty-four hour intragastric pH was monitored on day 7 of each period. Results, On day 7, median 24-h pH was 4.7, 5.1 and 4.7 after breakfast, dinner and bedtime dosing, respectively (P = 0.11), whereas night-time pH was 4.2, 5.0 and 4.4 (P = 0.13). The mean 24-h percentage of time over pH 4 was 62, 72 and 64 after breakfast, dinner and bedtime dosing, respectively (N.S.), and 54, 68 and 56 during night-time (P = 0.06). Nocturnal acid breakthrough incidence decreased from 100% at baseline to 83%, 55% and 75% after 7.00 am, 7.00 pm and 9.30 pm dosing, respectively (P = 0.18), and its mean duration dropped from 6.2 to 2.8, 1.0 and 2.2 h, respectively (P < 0.05). Conclusion, Seven-day administration of tenatoprazole provides a prolonged duration of acid suppression, especially during the night-time, with little effect of food or time of dosing. [source] Effect of low-dose rabeprazole and omeprazole on gastric acidity: results of a double blind, randomized, placebo-controlled, three-way crossover study in healthy subjectsALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2004S. Bruley des Varannes Summary Background :,The treatment of acid-related symptoms requires rapid and consistent acid suppression, especially with on-demand regimens. Aim :,To compare the antisecretory activity of low-dose rabeprazole and omeprazole in healthy, Helicobacter pylori -negative subjects. Methods :,In this randomized, double-blind, placebo-controlled, three-way crossover study, 27 volunteers were given rabeprazole 10 mg, omeprazole 10 mg, or placebo once daily for 7 days with a 10,14-day washout between treatments. Intragastric pH was monitored for 24-h on days 1 and 7 of each treatment. Results :,Median gastric pH was significantly higher with rabeprazole than with omeprazole or placebo: day 1: 2.3, 1.4 and 1.3, respectively (P = 0.0056, rabeprazole vs. omeprazole; P < 0.0001, rabeprazole vs. placebo); day 7: 3.7, 2.2 and 1.3, respectively (P = 0.0016 rabeprazole vs. omeprazole; P < 0.0001, rabeprazole vs. placebo). Time with gastric pH above 4 was significantly higher with rabeprazole than with omeprazole: day 1, 5.8 h vs. 3.7 h, respectively (P < 0.02); day 7, 10.5 h vs. 4.6 h, respectively (P = 0.0008). Conclusions :,Rabeprazole 10 mg provides more rapid acid inhibition compared with omeprazole 10 mg. After 7 days, the time with pH above 4 is more than doubled with rabeprazole 10 mg vs. omeprazole 10 mg. [source] The assessment of human regional drug absorption of free acid and sodium salt forms of Acipimox, in healthy volunteers, to direct modified release formulation strategyBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 9 2009Rajeev Menon Abstract Acipimox is an analog of nicotinic acid and is indicated for the treatment of dyslipidemia. It is also believed to improve glucose control by enhancing insulin sensitivity. The purpose of this study was to direct modified release (MR) formulation strategy by comparing the bioavailability of two forms of acipimox (free acid and sodium salt) from the distal small bowel (DSB) and colon with an immediate release formulation. Two parallel groups of healthy volunteers completed an open label, non-randomized, three-way crossover study. The rate and extent of acipimox absorption was highest following administration of the immediate release capsules, and was not influenced by the form of the drug administered. Following administration to the DSB, the relative bioavailability was approximately 52% and 30% for the salt form and free acid form, respectively. Following administration to the colon, the extent of absorption was further reduced. The data indicate that bioavailability from the DSB was limited by the solubility of the drug coupled with an absorption window, whilst absorption from the colon was limited by permeability. The study provided detailed information to support and guide the formulation strategy for a MR form of acipimox, which may improve the treatment of adult patients with type II diabetes and dyslipidemia. Copyright © 2009 John Wiley & Sons, Ltd. [source] 2323: Role of nitric oxide in optic nerve head blood flow regulation during isometric exercise in healthy humansACTA OPHTHALMOLOGICA, Issue 2010D SCHMIDL Purpose Nitric oxide (NO) is an important regulator of optic nerve head (ONH) blood flow in humans. We have previously shown that NO is also involved in choroidal blood flow regulation during isometric exercise. Inhibition of NO synthase (NOS) has been reported to shift choroidal pressure,flow curves during squatting to the right. The hypothesis for the present study was that inhibition of NOS may also influence ONH blood flow during isometric exercise. Methods To test this hypothesis, a randomized, double-masked, placebo-controlled, three-way crossover study was performed in 18 healthy volunteers. Subjects received on different study days intravenous infusions of NG-monomethyl- L-arginine (L-NMMA), phenylephrine, or placebo. During these infusion periods, subjects were asked to squat for 6 minutes. ONH blood flow was assessed with laser Doppler flowmetry, and ocular perfusion pressure (OPP) was calculated from mean arterial pressure and intraocular pressure. Results L-NMMA and phenylephrine increased resting OPP (p < 0.001 versus baseline), but only L-NMMA reduced resting ONH blood flow (p = 0.02 versus baseline). The relative increase in OPP during isometric exercise was comparable with all drugs administered (p = 0.69). In addition, the change of ONH blood flow was comparable with all administered drugs (p = 0.43). Conclusion These data indicate that NO plays an important role in the regulation of ONH blood flow at baseline, but does not change the response of ONH blood flow during isometric exercise. [source] | ||||||||||