Local view for "https://dbmi-icode-01.dbmi.pitt.edu/dikb/resource/Evidence/1160"
| Predicate | Value (sorted: default) |
|---|---|
| rdfs:label | |
| rdf:type | |
| ?:Evidence_enzyme_system | |
| ?:Evidence_type | |
| ?:content |
"Metabolism Following oral dosing, theophylline does not undergo any measurable first-pass elimination. In adults and children beyond one year of age, approximately 90%of the dose is metabolized in the liver. Biotransformation takes place through demethylation to 1-methylxanthine and 3-methylxanthine and hydroxylation to 1,3-dimethyluric acid. 1-methylxanthine is further hydroxylated, by xanthine oxidase, to 1-methyluric acid. About 6%of a theophylline dose is N-methylated to caffeine. Theophylline demethylation to 3-methylxanthine is catalyzed by cytochrome P-450 1A2, while cytochromes P-450 2E1 and P-450 3A3 catalyze the hydroxylation to 1,3-dimethyluric acid. Demethylation to 1-methylxanthine appears to be catalyzed either by cytochrome P-450 1A2 or a closely related cytochrome. In neonates, the N-demethylation pathway is absent while the function of the hydroxylation pathway is markedly deficient. The activity of these pathways slowly increases to maximal levels by one year of age."
|
| dc:creator | |
| dc:date |
"09/24/2009 14:43:07"
|
| rdfs:seeAlso |
All properties reside in the graph file:///home/swish/src/ClioPatria/guidelines/dikb.ttl
The resource appears as object in one triple:
{ 1-methylxanthine_has_metabolite_1-methyluric-acid, <http://purl.org/swan/1.2/swan-commons#citesAsSupportingEvidence>, evidence_1016 }