Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-6-18
pubmed:abstractText
1: The pharmacokinetics and metabolism of 14C-levetiracetam, a new anti-epileptic agent, in mouse, rat, rabbit and dog after a single oral dose were investigated. Moreover, the in vitro hydrolysis of levetiracetam to its major carboxylic metabolite by rat tissue homogenates was investigated to identify tissues involved in the production of the metabolite. Data are also presented on the induction of the enzyme(s) involved in levetiracetam hydrolysis in the rat. 2: Levetiracetam was rapidly and almost completely absorbed. The unchanged drug accounted for a very high percentage of plasma radioactivity. Levetiracetam did not bind to plasma proteins. Although brain radioactivity concentrations were lower than those of whole blood at early time points, brain-to-blood ratios increased over time. The predominant route of elimination of total 14C was excretion via urine, accounting for about 81, 93, 87 and 89% of the dose in the mouse, rat, rabbit and dog, respectively. Consequently, levetiracetam was poorly metabolized. It was submitted in vivo to hydrolysis and/or oxidation. Hydrolysis of the amide function of levetiracetam produced the corresponding acid. However, levetiracetam could also be oxidized at positions 3 and 4 of the 2-oxopyrrolidine ring. Finally, the compound and the corresponding acid metabolite could be oxidized at position 5 of the 2-oxopyrrolidine ring and then hydrolysed with the opening of the ring. 3: All the investigated rat tissues (liver, kidney, lung, brain, small intestine mucosa) had the potential to produce the acid metabolite. By contrast, the acid was undetectable following incubation of levetiracetam with buffer alone or heat-denaturated liver fractions. 4: No marked species or sex differences were observed in the absorption, disposition and metabolism of levetiracetam. 5:The hydrolysis of levetiracetam is carried out by an enzymatic process characterized by a broad tissue distribution. In the rat, the enzyme system hydrolysing levetiracetam is not induced by phenobarbital, at least under the experimental conditions used herein, whereas the enzyme system(s) involved in the other metabolic pathways is induced.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0049-8254
pubmed:author
pubmed:copyrightInfo
Copyright 2004 Taylor and Francis Ltd.
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
281-300
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Comparative pharmacokinetics and metabolism of levetiracetam, a new anti-epileptic agent, in mouse, rat, rabbit and dog.
pubmed:affiliation
UCB S. A., Pharma Sector, Department of Global Product Safety and Metabolism, 21 rue de Neuilly, F-92003 Nanterre, France. margherita.strolin@ucb-group.com
pubmed:publicationType
Journal Article, Comparative Study, In Vitro