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Dose Study (dose + study)
Selected AbstractsAn Open-Label, Multicenter, Flexible Dose Study to Evaluate the Efficacy and Safety of Viagra® (Sildenafil Citrate) in Korean Men with Erectile Dysfunction and Arterial Hypertension who are Taking Antihypertensive AgentsTHE JOURNAL OF SEXUAL MEDICINE, Issue 10 2008Hyun Jun Park MD ABSTRACT Introduction., Erectile dysfunction (ED) is common among men taking antihypertensive agents to control blood pressure. Aim., We evaluated the efficacy and safety of sildenafil citrate in men with ED taking antihypertensive agents. Methods., A total of 198 male subjects, aged 20 years and older were enrolled. This study was conducted for 10 weeks as an open-label, multicenter and flexible dose trial with a 2-week screening period and an 8-week treatment phase. Main Outcome Measures., Subjects were asked to complete Event Log Worksheets, as well as the International Index of Erectile Function (IIEF) and the Global Efficacy Assessment Questions (GEAQ) questionnaires during the study period. Results., The average age among the 167 subjects who completed the study was 55.8 (31.7 to 77.1). The scores for questions 3 and 4 of IIEF improved from 2.3 and 1.8 at baseline to 3.7 and 3.4 at week 4 and 3.8 and 3.4 at week 8, respectively. There were 86.3% of the patients reported improved erectile function at week 8; 88.3% of the patients reported improved ability to achieve sexual intercourse at week 8. There were no significant differences observed in the responses to questions 3 and 4 of IIEF and GEAQ by the number of antihypertensive agents taken. The adverse events were facial flushing (20.1%), headache (11.7%), palpitation (5.0%), rhinitis (2.8%), URI (2.8%), dizziness (2.2%), dyspnea (2.2%), and nausea (1.7%). Conclusions., Sildenafil citrate is an effective treatment for ED; it is safe and well tolerated by patients with ED taking multiple antihypertensive agents for arterial hypertension. Park HJ, Park NC, Shim HB, Park JK, Lee SW, Park K, Kim SW, Moon KH, Lee DH, and Yoon SJ. An open-label, multicenter, flexible dose study to evaluate the efficacy and safety of Viagra® (sildenafil citrate) in Korean men with erectile dysfunction and arterial hypertension who are taking antihypertensive agents. J Sex Med 2008;5:2405,2413. [source] Safety, Tolerability and Pharmacokinetics of TAS-108, a Novel Anti-Oestrogen, in Healthy Post-Menopausal Japanese Women: A Phase I Single Oral Dose StudyBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 5 2009Yuji Kumagai The present study was conducted to investigate the safety, tolerability and pharmacokinetics of TAS-108 following the administration at a single oral dose of 40 mg to up to 120 mg in 12 post-menopausal women and the effect of food on the pharmacokinetics of the drug. All adverse events were mild and involved transient symptoms that resolved without therapeutic intervention. TAS-108 was readily absorbed and plasma levels of TAS-108 steadily declined, apparently in a multi-exponential manner. Cmax and AUC0-12 were proportionally increased with increasing dose of TAS-108. The Cmax and AUC0-t of TAS-108 and its metabolite, deEt-TAS-108, were significantly increased to approximately 150% when TAS-108 was administered after a meal. Food did not affect the elimination half-life of TAS-108 or its metabolites. In this escalating dose-study of TAS-108, the drug was well tolerated by healthy post-menopausal Japanese women. The pharmacokinetics of TAS-108 indicated dose proportionality, and its bioavailability was significantly increased by food intake. [source] Improvement in social competence in patients with schizophrenia: a pilot study using a performance-based measure using virtual reality,HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 8 2009Kyung-Min Park Abstract Objective The objective of this study was to explore the possibility of the use of Virtual Reality Functional Skills Assessment (VRFSA) in a future regular clinical trial, as well as to report a preliminary result about effectiveness of atypical antipsychotics to social competence in schizophrenia. Methods We developed the VRFSA that measured subjects' performances automatically and used analogue scale rather than Likert scale. Twenty-four female patients with paranoid schizophrenia and 15 healthy females were recruited. This was a 6-week, randomized, open-label, and flexible dose study, and 2 treatments (baseline versus post-treatment),×,2 skills phases (receptive versus expressive),×,2 patient groups (aripiprazole versus risperidone) analysis of variance was used in the final analysis. Results There was a significant difference in the VRFAS between the patients and the healthy subjects (p,<,0.05). Eighteen patients were included in the final analysis. We found larger treatment effect than those found in previous studies, and significant treatment,×,skills phase,×,group interaction effect on the VRFAS. Conclusions Our results suggest that the VRFAS is strongly sensitive to changes in social competence and thus especially beneficial in short-term clinical trials. In addition, atypical antipsychotics can improve social competence and differentially improve receptive skills and expressive skills in schizophrenia. Copyright © 2009 John Wiley & Sons, Ltd. [source] Pharmacokinetics and pharmacodynamics of prasugrel in subjects with moderate liver diseaseJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 5 2009D. S. Small PhD Summary Background and Objective:, Prasugrel is a thienopyridine antiplatelet agent under investigation for the prevention of atherothrombotic events in patients with acute coronary syndrome who undergo percutaneous coronary intervention. Patients with chronic liver disease are among those in the target population for prasugrel. As hepatic enzymes play a key role in formation of prasugrel's active metabolite, hepatic impairment could affect the safety and/or efficacy of prasugrel in such patients. Methods:, This was a parallel-design, open-label, multiple dose study of 30 subjects, 10 with moderate hepatic impairment (Child-Pugh Class B) and 20 with normal hepatic function. Prasugrel was administered orally as a 60-mg loading dose (LD) and daily 10-mg maintenance doses (MDs) for 5 days. Pharmacokinetic parameters (AUC0,t, Cmax and tmax) and maximal platelet aggregation (MPA) by light transmission aggregometry were assessed after the LD and final MD. Results and Discussion:, Exposure to prasugrel's active metabolite was comparable between healthy subjects and those with moderate hepatic impairment. Point estimates for the ratios of geometric least square means for AUC0,t and Cmax after the LD and last MD ranged from 0·91 to 1·14. MPA to 20 ,m ADP was similar between subjects with moderate hepatic impairment and healthy subjects for both the LD and MD. Prasugrel was well tolerated by all subjects, and adverse events were mild in severity. Conclusion:, Moderate hepatic impairment appears to have no effect on exposure to prasugrel's active metabolite. Furthermore, MPA results suggest that moderate hepatic impairment has little or no effect on platelet aggregation relative to healthy controls. Overall, these results suggest that a dose adjustment would not be required in moderately hepatically impaired patients taking prasugrel. [source] Scintigraphic study to investigate the effect of food on a HPMC modified release formulation of UK-294,315JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2009J. Davis Abstract The objective of the study was to use the combined approach of gamma scintigraphy and pharmacokinetics, in order to understand the mechanisms explaining the pharmacokinetic differences observed for a modified release (MR) formulation, when administered either in the fed or fasted state. Ten healthy subjects were recruited into a randomized three period single dose study, each subject receiving UK-294,315 40 mg IR (fasted), 100 mg MR (fasted) or 100 mg MR (after a high fat meal). Cmax values were markedly higher for the MR tablet in the fed state versus fasted and mean residence time was about 3 h longer for fasted versus fed; there was little difference in apparent oral clearance. In the fasted state, average gastric emptying of the intact tablet occurred at 1.2 h postdose, with gastric emptying of intact tablet observed in all subjects. In the fed state, rapid disintegration of the MR tablet was observed by scintigraphy, with 7/9 subjects showing complete disintegration in the stomach. Complete disintegration occurred 10.1 h postdose in the fasted state versus 5.9 h after a high fat meal. The study showed that in the fed state, the MR tablet eroded more rapidly than in the fasted state, leading to an overall increase in the rate of absorption. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1568,1576, 2009 [source] The pharmacokinetics and pharmacodynamics of alfaxalone in cats after single and multiple intravenous administration of Alfaxan® at clinical and supraclinical dosesJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2008T. WHITTEM This study aimed to determine the pharmacokinetic parameters and pharmacodynamics of alfaxalone in a 2-hydroxypropyl-,-cyclodextrin alfaxalone formulation (Alfaxan®, Jurox Pty Ltd, Rutherford, NSW, Australia) in cats after single administration at clinical and supraclinical dose rates and as multiple maintenance doses. First, a prospective two-period cross-over study was conducted at single clinical and supraclinical doses. Second, a single group multiple dose study evaluated the effect of maintenance doses. Eight (five female and three male) domestic cats completed the cross-over experiment and six female cats completed the multiple dose study. In the first experiment, alfaxalone was administered intravenously (IV) at 5 or 25 mg/kg with a washout period of 14 days. In the second experiment, alfaxalone was administered IV at 5 mg/kg followed by four doses each of 2 mg/kg, administered at onset of responsiveness to a noxious stimulus. Blood was collected at prescribed intervals and analysed by LCMS for plasma alfaxalone concentration. Noncompartmental pharmacokinetics were used to analyse the plasma alfaxalone data. The plasma clearance of alfaxalone at 5 and 25 mg/kg differed statistically at 25.1 and 14.8 mL/kg/min respectively. The elimination half lives were 45.2 and 76.6 min respectively. Alfaxalone has nonlinear pharmacokinetics in the cat. Nevertheless, for cats dosed with sequential maintenance doses, a regression line through their peak plasma concentrations indicated that there was no clinically relevant pharmacokinetic accumulation. The duration of nonresponsiveness after each maintenance dose was similar at approximately 6 min, indicating a lack of accumulation of pharmacodynamic effect. The cardiovascular and respiratory parameters measured in cats after administration of the labelled doses of Alfaxan® were stable. In conclusion, the pharmacokinetics of alfaxalone in cats are nonlinear. At clinical dose rates, however, neither alfaxalone nor its effects accumulated to a clinically relevant extent. Further, in the un-premedicated cat the induction and maintenance of surgical anaesthesia was free of untoward events after a dose of 5 mg alfaxalone/kg body weight followed by four sequential doses of 2 mg/kg as needed (i.e., approximately 7 to 8 mg/kg/h). [source] Modelling covariance structure in ascending dose studies of isolated tissues and organsPHARMACEUTICAL STATISTICS: THE JOURNAL OF APPLIED STATISTICS IN THE PHARMACEUTICAL INDUSTRY, Issue 2 2003Richard John Brammer This paper describes the analysis of two pharmacology assays: the guinea pig papillary muscle assay (an example of an isolated tissue assay) and an assay looking at pressure changes in isolated rat lungs. Both assays use an ascending dose design to minimize carryover effects. This is often necessary in these studies, due to the limited life span of the tissues. Various mixed models, with different covariance structures, are fitted to find the most appropriate model. These are then compared to two other possible methods of analysis: paired t-tests and two-way analysis of variance. For both assays, the mixed model was found to be the best approach. These examples illustrate the importance of modelling covariance structure correctly in any ascending dose study, whether in isolated organs/tissues, in animals or phase I volunteers. Copyright © 2003 John Wiley & Sons, Ltd. [source] An Open-Label, Multicenter, Flexible Dose Study to Evaluate the Efficacy and Safety of Viagra® (Sildenafil Citrate) in Korean Men with Erectile Dysfunction and Arterial Hypertension who are Taking Antihypertensive AgentsTHE JOURNAL OF SEXUAL MEDICINE, Issue 10 2008Hyun Jun Park MD ABSTRACT Introduction., Erectile dysfunction (ED) is common among men taking antihypertensive agents to control blood pressure. Aim., We evaluated the efficacy and safety of sildenafil citrate in men with ED taking antihypertensive agents. Methods., A total of 198 male subjects, aged 20 years and older were enrolled. This study was conducted for 10 weeks as an open-label, multicenter and flexible dose trial with a 2-week screening period and an 8-week treatment phase. Main Outcome Measures., Subjects were asked to complete Event Log Worksheets, as well as the International Index of Erectile Function (IIEF) and the Global Efficacy Assessment Questions (GEAQ) questionnaires during the study period. Results., The average age among the 167 subjects who completed the study was 55.8 (31.7 to 77.1). The scores for questions 3 and 4 of IIEF improved from 2.3 and 1.8 at baseline to 3.7 and 3.4 at week 4 and 3.8 and 3.4 at week 8, respectively. There were 86.3% of the patients reported improved erectile function at week 8; 88.3% of the patients reported improved ability to achieve sexual intercourse at week 8. There were no significant differences observed in the responses to questions 3 and 4 of IIEF and GEAQ by the number of antihypertensive agents taken. The adverse events were facial flushing (20.1%), headache (11.7%), palpitation (5.0%), rhinitis (2.8%), URI (2.8%), dizziness (2.2%), dyspnea (2.2%), and nausea (1.7%). Conclusions., Sildenafil citrate is an effective treatment for ED; it is safe and well tolerated by patients with ED taking multiple antihypertensive agents for arterial hypertension. Park HJ, Park NC, Shim HB, Park JK, Lee SW, Park K, Kim SW, Moon KH, Lee DH, and Yoon SJ. An open-label, multicenter, flexible dose study to evaluate the efficacy and safety of Viagra® (sildenafil citrate) in Korean men with erectile dysfunction and arterial hypertension who are taking antihypertensive agents. J Sex Med 2008;5:2405,2413. [source] Tissue distribution of the novel DPP-4 inhibitor BI 1356 is dominated by saturable binding to its target in ratsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 5 2009Holger Fuchs Abstract BI 1356 (INN: linagliptin) is an inhibitor of dipeptidyl peptidase-4 (DPP-4). This study investigated whether saturable binding of BI 1356 to its target DPP-4 occurs in tissues and whether drug accumulation occurs at these sites in vivo. In order to test these hypotheses, the tissue distribution of BI 1356 was determined in wild-type and DPP-4 deficient rats at different dose levels by means of whole body autoradiography and measurement of tissue radioactivity concentrations after single i.v. dosing of [14C]-radio labeled BI 1356. The accumulation behavior of drug-related radioactivity in tissues was further explored in an oral repeat dose study. Tissue levels of [14C]BI 1356 related radioactivity were markedly lower in all investigated tissues of the DPP-4 deficient rats and the difference of the dose-dependent increase of radioactivity tissue levels between both rat strains indicates that tissue distribution at low doses of BI 1356 is dominated by binding of BI 1356 to DPP-4 in tissues. As the binding to DPP-4 is strong but reversible, the tissue binding results in a long terminal half-life in several tissues including plasma. The binding capacity to DPP-4 is, however, limited. In the rat, saturation of DPP-4 binding is suggested at an intravenous dose above 0.01,0.1,mg/kg [14C]BI 1356. As the DPP-4 binding capacity is saturated already at low doses, accumulation of BI 1356 in tissues is unlikely, despite the long persistence of low amounts in the body. Copyright © 2009 John Wiley & Sons, Ltd. [source] The effects of ritonavir and lopinavir/ritonavir on the pharmacokinetics of a novel CCR5 antagonist, aplaviroc, in healthy subjectsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 3 2006Kimberly K. Adkison Aims This study assessed the effects of the CYP3A inhibitors lopinavir/ritonavir (LPV/r) on the steady-state pharmacokinetics (PK) of aplaviroc (APL), a CYP3A4 substrate, in healthy subjects. Methods In Part 1, APL PK was determined in eight subjects who received a single oral 50-mg APL test dose with/without a single dose of 100 mg ritonavir (RTV). Part 2 was conducted as an open-label, single-sequence, three-period repeat dose study in a cohort of 24 subjects. Subjects received APL 400 mg every 12 h (b.i.d.) for 7 days (Period 1), LPV/r 400/100 mg b.i.d. for 14 days (Period 2) and APL 400 mg +,LPV/r 400/100 mg b.i.d. for 7 days (Period 3). All doses were administered with a moderate fat meal. PK sampling occurred on day 7 of Periods 1 and 3 and day 14 of Period 2. Results In Part 1, a single RTV dose increased the APL AUC0,, by 2.1-fold [90% confidence interval (CI) 1.9, 2.4]. Repeat dose coadministration of APL with LPV/r increased APL exposures to a greater extent with the geometric least squares mean ratios (90% CI) being 7.7 (6.4, 9.3), 6.2 (4.8, 8.1) and 7.1 (5.6, 9.0) for the APL AUC, Cmax, and Cmin, respectively. No change in LPV AUC or Cmax and a small increase in RTV AUC and Cmax (28% and 32%) were observed. The combination of APL and LPV/r was well tolerated and adverse events were mild in severity with self-limiting gastrointestinal complaints most commonly reported. Conclusions Coadministration of APL and LPV/r was well tolerated and resulted in significantly increased APL plasma concentrations. [source] | ||||||||||