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Variable Absorption (variable + absorption)
Selected AbstractsVariable absorption of clavulanic acid after an oral dose of 25 mg/kg of Clavubactin® and Synulox® in healthy dogsJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2003T. B. Vree The aims of this investigation were to calculate the pharmacokinetic parameters and to identify parameters, based on individual plasma concentration,time curves of amoxicillin and clavulanic acid in dogs, that may govern the observed differences in absorption of both drugs. The evaluation was based on the data from plasma concentration,time curves obtained following a single dose in an open, randomized, two-way crossover study involving 24 male Beagle dogs treated with two Amoxi,Clav formulations (A Clavubactin® and B Synulox®, each with 200/50 mg). Plasma amoxicillin and clavulanic acid concentrations were determined using validated bioassay methods. The half-life of elimination of amoxicillin was 1.5 h (t1/2 = 1.52 ± 0.19 h, Cmax = 11.4 ± 2.74 ,g/mL), and that of clavulanic acid 0.76 h (t1/2 = 0.71 ± 0.23 h, Cmax = 2.06 ± 1.05 ,g/mL). There was a fivefold variation in the AUCt of clavulanic acid for both formulations, while the AUCt of amoxicillin varied by a factor of 2. The mean ratio of the AUCt amoxicillin : clavulanic acid was 12.7 ± 3.65 for formulation A and 11.8 ± 5.22 for formulation B (P = 0.51). [source] Giant repeated ejections from GRS 1915+105MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2000R. P. Fender We report simultaneous millimetre and infrared observations of a sequence of very large amplitude quasi-periodic oscillations from the black hole X-ray binary GRS 1915+105. These oscillations are near the end of a sequence of over 700 repeated events as observed at 15 GHz, and are simultaneous at the mm and infrared wavelengths to within our time resolution (4 min), consistent with the respective emitting regions being physically close near the base of the outflow. One infrared event appears to have no mm counterpart, perhaps owing to highly variable absorption. The overall radio,mm,infrared spectrum around the time of the observations does suggest some absorption at lower frequencies. We calculate the energy and mass-flow into the outflow for a number of different assumptions, and find that the time-averaged power required to produce the observed synchrotron emission cannot be much lower than 3×1038 erg s,1, and is likely to be much larger. This minimum power requirement is found regardless of whether the observed emission arises in discrete ejections or in an internal shock in a quasi-continuous flow. Depending on the similarity of the physical conditions in the two types of ejection, GRS 1915+105 may be supplying more power (and mass, if both have the same baryonic component) to the jet during periods of repeated oscillations than during the more obvious larger events. [source] Improved CNS tolerability following conversion from immediate- to extended-release carbamazepineACTA NEUROLOGICA SCANDINAVICA, Issue 6 2004A. D. Miller Objectives , Tolerability of ,narrow therapeutic ratio' (NTR) antiepileptic drugs may improve with uniform drug delivery. We determined whether conversion from immediate-release carbamazepine (IR-CBZ) to extended-release carbamazepine (ER-CBZ) decreased the incidence of CNS side-effects associated with drug concentration oscillations. Methods , We compared CNS side effects and seizure frequency for patients with partial-onset seizures (n = 61) treated with IR-CBZ for ,1 year with conversion to ER-CBZ for ,1 year. We compared tolerability findings with absorption variability of the formulations. Results , Incidence of CNS side-effects decreased from 49% during IR-CBZ treatment to 20% following conversion to ER-CBZ. Patients also had improved tolerability of high doses (,1200 mg/day) during ER-CBZ treatment. Pharmacokinetic analysis showed absorption and drug concentration were much more variable for the immediate-release formulation. Conclusions , This study suggests that ER-CBZ formulations, with smoother drug delivery and less variable absorption, provide improved CNS tolerability compared with immediate-release formulations. [source] Pharmacokinetics and tolerability of intravenous busulfan in hematopoietic stem cell transplantationCLINICAL TRANSPLANTATION, Issue 3 2007Yo-Han Cho Abstract:, Intravenous (IV) busulfan has been developed to overcome variable absorption of oral busulfan and tested in several trials. We tested its pharmacological properties and tolerability in 16 Korean stem cell transplantation (SCT) patients. IV busulfan was administered at 0.8 mg/kg every six h for a total of 16 doses (days ,7 to ,4), which was followed by cyclophosphamide administration at 60 mg/kg every 24 h for two d (days ,3 and ,2). The median AUCinf values (at the first dose) and AUCss (at the steady state) were 1060.4 ,M·min (range: 511.1,1812.7) and 1092.5 ,M·min (range: 539.7,1560.8) respectively. All patients had an AUCinf of <1500 ,M·min at the first dose, and 13 of the 16 (81.3%) maintained AUCss levels between 800 and 1500 ,M·min. Thirteen of 16 patients showed successful engraftments but four patients (25%) developed hepatic VOD (two of which were fatal), three of whom had advanced disease at the time of SCT. Overall, pharmacokinetics of IV busulfan in our SCT patients appeared comparable with those observed in other study. However, hepatic VOD was a major morbidity in patients with advanced disease. [source] | ||||||||||