Propofol metabolism is enhanced after repetitive ketamine administration in rats: the role of cytochrome P-450 2B induction.
Br J Anaesth
; 97(3): 351-8, 2006 Sep.
Article
in En
| MEDLINE
| ID: mdl-16845130
ABSTRACT
BACKGROUND:
In a series of ex vivo and in vivo studies we investigated the ability of repetitive ketamine administration to alter the metabolism and anaesthetic effect of propofol and the role of ketamine-mediated P-450 2B induction in rats.METHODS:
Male Wistar rats were pretreated with 80 mg kg(-1) ketamine i.p. twice daily for 4 days. Pentoxyresorufin O-dealkylation (PROD), P-450 2B protein and mRNA were determined. Residual propofol concentration was measured after incubating hepatic microsomes with 100 muM propofol. Sleeping times induced by i.p. 80 mg kg(-1) propofol were determined. Orphenadrine, a P-450 2B inhibitor, was added in both ex vivo and in vivo studies. Finally, serial whole blood propofol concentrations were determined after i.v. infusion of 15 mg kg(-1) propofol.RESULTS:
Ketamine pretreatment produced 5.4-, 3.4- and 1.7-fold increases in hepatic PROD activity, P-450 2B protein and mRNA, respectively. Residual propofol concentration was 46% lower after incubation with microsomes from ketamine-pretreated rats than in the control group. The addition of orphenadrine to ketamine-pretreated microsomes produced an increase in residual propofol concentration in a concentration-dependent manner. Ketamine pretreatment reduced propofol sleeping time to 12% of the control, which was reversed by orphenadrine. The whole blood propofol concentration in ketamine-pretreated rats was significantly lower than that of control rats at 1, 2, 4 and 8 min after cessation of propofol infusion.CONCLUSIONS:
Repetitive ketamine administration enhances propofol metabolism and reduces propofol sleeping time in rats. We suggest that P-450 2B induction may produce ketamine-propofol interaction in anaesthetic practice.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Steroid Hydroxylases
/
Aryl Hydrocarbon Hydroxylases
/
Propofol
/
Anesthetics, Intravenous
/
Cytochrome P-450 CYP2B1
/
Ketamine
Limits:
Animals
Language:
En
Journal:
Br J Anaesth
Year:
2006
Document type:
Article
Affiliation country:
Taiwán