Escitalopram is a weak inhibitor of the CYP2D6-catalyzed O-demethylation of (+)-tramadol but does not reduce the hypoalgesic effect in experimental pain.
Clin Pharmacol Ther
; 86(6): 626-33, 2009 Dec.
Article
in En
| MEDLINE
| ID: mdl-19710642
ABSTRACT
Tramadol is O-demethylated to the active metabolite (+)-O-desmethyltramadol ((+)-M1) via CYP2D6, an enzyme that is weakly inhibited by escitalopram. We investigated the possibility of a pharmacokinetic (PK) and pharmacodynamic (PD) effect of escitalopram on tramadol metabolism. Fifteen healthy subjects completed this randomized, double-blind, three-phase, crossover trial. Combinations of escitalopram 20 mg/day or placebo together with tramadol 150 mg or placebo were used. Blood samples for pharmacokinetics were drawn at 0-24 h after medication. The analgesic effect of (+)-M was assessed by the cold pressor test (CPT) (area under effect curve, 1-12 h after medication (AUEC(1-12))). The median area under plasma concentration-time curve extrapolated to infinity (AUC(0-infinity)) of (+)-M1 was 2.75 micromol/l.h after placebo pretreatment compared with 1.95 micromol/l.h after escitalopram (P = 0.0027). The mean AUEC(1-12) of CPT were 4,140 and 4,388 cm.s after placebo and escitalopram, respectively (P = 0.71). Although escitalopram is a weak inhibitor of CYP2D6, it does not impair the analgesic effect of tramadol.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pain
/
Tramadol
/
Citalopram
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Selective Serotonin Reuptake Inhibitors
/
Enzyme Inhibitors
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Cytochrome P-450 CYP2D6 Inhibitors
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Analgesics, Opioid
Type of study:
Clinical_trials
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
En
Journal:
Clin Pharmacol Ther
Year:
2009
Document type:
Article
Affiliation country: