513 research outputs found
Reduction of Steady-State Valproate Levels by Other Antiepileptic Drugs
Steady-state plasma valproate (VPA) levels were analyzed in 37 children after 6 weeks of VPA therapy. Twenty-six patients were receiving other antiepileptic drugs in addition to VPA (experimental group). Eleven patients who received VPA alone served as controls. The mean VPA dose was not statistically different for the two groups (experimental group, 35.4 mg/kg/ day, 11.6 SD; control group, 31.1 mg/kg/day, SD 6.6) The mean plasma VPA level was significantly lower for the experimental group (63.0 Îg/m1, SD 21.8) than for the control (99.3 Îg/m1), SD 23.3) ( p < 0.01). VPA levelrdose ratio (LDR) was also reduced in the experimental group (1.92, SD 0.75) as compared to controls (3.26, SD 0.65) ( p < 0.01). Within the experimental group the VPA levels and VPA LDR were significantly reduced in patients receiving either phenytoin or phenobarbital. The data suggest that other antiepileptic drugs significantly alter the steady-state level to dose relationship for VPA. RĂSUMĂ Le taux plasmatique Ă l'Ăquilibre du valproate de sodium (VPA) a ĂtĂĂtudiĂ chez 37 enfants aprĂs 6 semaines de thĂrapeutique. Vingt six patients reĂoivent d'autres mĂdicaments antiĂpileptiques associĂs au VPA (groupe expĂrimental) alors que 11 sujets tĂmoins ne reĂoivent que le VPA seul. La posologie moyenne du VPA n'est pas significativement diffĂrente entre les deux groupes (35,4 mg/kg/jour ± 11,6 centre 31,1 mg/kg/jour ± 6,6). Le taux plasmatique de VPA est significativement plus bas dans le groupe experimental (63,0 Îg/ml ± 21,8) contre 99,3 Îg/ml ± 23,3 dans le groupe tĂmoin ( p < 0,01). Le rapport taux plasmatique/posologie (LDR) a ĂtĂ diminuĂ dans le groupe expĂrimental (1,92 ± 0,75) par rapport au groupe tĂmoin (3,26 ± 0,65), p < 0,01 en particulier chez les malades recevant de la phĂnytoĂne ou du phĂnobarbital. La posologie moyenne du VPA n'Ătant pas significativement diffĂrente dans les deux groupes, les faits observĂs suggĂrent que l'addition d'autres antiĂpileptiques est capable de modifier le taux Ă l'Ăquilibre du VPA plasmatique en fonction de la dose administrĂe. RESUMEN Se analizaron los niveles estables de valproato en plasma (VPA) en 37 niĂos despuĂs de 6 semanas de terapia con VPA. Ventiseis pacientes recibĂan otros fĂrmacos ademĂs de VPA (grupo experimental) y once sĂlo tomaban VPA y sirvieron como controles. La dosis media de VPA no fue significativamente distinta en los dos grupos (grupo experimental: 35,4 mg/kg/dĂa, DS 11,6; grupo control: 31.1 mg/kg/dĂa, DS 6,6). El nivel plasmĂtico medio de VPA fue significativamente inferior en el grupo experimental (63,0 Îg/ml, DS 21,8) que en el control (99,3 Îg/ml, DS 23,3), p < 0,01. La relaciĂn nivel de VPA: dosis (LDR) estaba tambiĂn reducida en el grupo experimental (1,92, DS 0,75) al compararla con los controles (3,26, DS 0,65), p < 0,01. Dentro del grupo experimental los niveles de VPA y la LDR estaban significativamente reducidos en pacientes que tomaban fenitoĂna o fenobarbital. La dosis media no fue diferente entre los grupos experimental y control. Estos datos sugieren que la ingestiĂn de otros fĂrmacos alteran de modo significativo los niveles estables de VPA en relaciĂn con la dosis. ZUSAMMENFASSUNG In steady-state befindliche Plasma Valproatspiegel (VPA) wurden bei 37 Kindern nach 6 wĂchiger VPA-Therapie analysiert. 26 Patienten erhielten zusĂtzlich zum VPA andere Antiepileptika (experimentelle Gruppe). 11 Patienten, die VPA alleine bekamen, dienten als Kontrollen. Die mittlere VPA-Dosis war in beiden Gruppen nicht signifikant Vunterschiedlich (experimentelle Gruppe 35,4 mg/kg pro Tag, 11,6 SD; Kontrollgruppe 31,1 mg/kg pro Tag, SD 6,6). Der mittlere Plasma VPA-Spiegel war signifikant niedriger in der experimentellen Gruppe (63,0 Îg/ml, SD 21,8) als in der Kontrollgruppe (99,3 Îg/m1, SD 23,3), p < 0.01. Das VerhĂltnis VPA-Spiegel: Dosis (LDR) war in der experimentellen Gruppe ebenfalls reduziert (1,92, SD 0,75) gegenuber der Kontrollgruppe (3,26, SD 0,65), p < 0.01. Innerhalb der experimentellen Gruppe waren die VPA-Spiegel und die VPA/LDR bei Patienten, die entweder Phenytoin oder Phenobarbital bekamen, signifikant erniedrigt. Die mittlere VPA-Dosis war nicht signifikant unterschiedlich in der experimentellen und in der Kontrollgruppe. Diese Daten lassen vermuten, daĂ andere Antiepileptika signifikanterweise den Steady-state-Spiegel im Hinblick auf die verabfolgte Dosis VPA Ăndern.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66058/1/j.1528-1157.1981.tb06154.x.pd
Collusion through Joint R&D: An Empirical Assessment
This paper tests whether upstream R&D cooperation leads to downstream collusion. We consider an oligopolistic setting where firms enter in research joint ventures (RJVs) to lower production costs or coordinate on collusion in the product market. We show that a sufficient condition for identifying collusive behavior is a decline in the market share of RJV-participating firms, which is also necessary and sufficient for a decrease in consumer welfare. Using information from the US National Cooperation Research Act, we estimate a market share equation correcting for the endogeneity of RJV participation and R&D expenditures. We find robust evidence that large networks between direct competitors â created through firms being members in several RJVs at the same time â are conducive to collusive outcomes in the product market which reduce consumer welfare. By contrast, RJVs among non-competitors are efficiency enhancing
Pharmacokinetic parameters estimated from intravenous data by uniform methods and some of their uses
This article summarizes phamacokinetic parameters of 20 different drugs. The parameters were estimated by uniform methods for an n- compartment open mammillary model in which elimination was assumed to occur only from the central compartment. For various reasons, some of the reported parameters differ appreciably from those reported in the original articles. Some uses of the parameters are discussed .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45070/1/10928_2005_Article_BF01066219.pd
The Evolution of Income Inequality in Germany and Switzerland Since the Turn of the Millennium
Effect of different stress conditions on the stability of quercetin-loaded lipid microparticles produced with babacu ( Orbignya speciosa ) oil: evaluation of their potential use in food applications
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