title: Effect of age and postoperative time on cytochrome p450 enzyme activity following liver transplantation.
abstract: This study evaluates the changes in cytochrome P450 (CYP) enzyme activity in orthotopic liver transplant (OLTx) patients in relation to recipient age and postoperative time. Thirty-eight stable OLTx patients, separated into younger and older age groups, and 21 healthy subjects were given a 5-drug cocktail including chlorzoxazone (CYP2E1), caffeine (CYP1A2), dapsone (CYP3A4), mephenytoin (CYP2C19), and debrisoquin (CYP2D6). The phenotypic indexes were determined for each associated enzyme. Compared to young healthy subjects, the CYP2E1 capacity was significantly increased in younger and older OLTx patients (P < .001), while the CYP2C19 capacity was decreased significantly in younger and older OLTx patients within 30 days postoperatively (P < .01). The CYP2D6 capacity was significantly lower after 30 days postoperatively in older OLTx patients (P < .05). The authors conclude that within 30 days postoperatively, CYP2E1 capacity was markedly elevated in OLTx patients, while 2C19 function was significantly reduced. CYP2D6 capacity was impaired after 30 days postoperatively. Younger and older OLTx patients experienced similar changes in major CYP450 enzyme capacity following liver transplantation.
authors.affiliation: School of Pharmacy, University of Southern California, 1985 Zonal Ave, PSC 100, Los Angeles, CA 90033, USA.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Liu
authors.forename: Reginald F
authors.initials: RF
authors.lastname: Frye
authors.forename: Robert A
authors.initials: RA
authors.lastname: Branch
authors.forename: Raman
authors.initials: R
authors.lastname: Venkataramanan
authors.forename: John J
authors.initials: JJ
authors.lastname: Fung
authors.forename: Gilbert J
authors.initials: GJ
authors.lastname: Burckart
mesh_terms: D000368:Aged; D002986:Clinical Trials as Topic; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D005260:Female; D006801:Humans; D016031:Liver Transplantation / Q000502:physiology* / Q000706:statistics & numerical data; D008297:Male; D010641:Phenotype; D011184:Postoperative Period; D013997:Time Factors
chemical_list: D003577:Cytochrome P-450 Enzyme System