RT Journal Article
SR Electronic
T1 Evaluation of Clopidogrel Conjugation Metabolism: PK Studies in Man and Mice of Clopidogrel Acyl Glucuronide
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 1490
OP 1497
DO 10.1124/dmd.116.071092
VO 44
IS 9
A1 Simona Nicoleta Savu
A1 Luigi Silvestro
A1 Mariana Surmeian
A1 Lina Remis
A1 Yuksel Rasit
A1 Simona Rizea Savu
A1 Constantin Mircioiu
YR 2016
UL http://dmd.aspetjournals.org/content/44/9/1490.abstract
AB The existence of a glucuronide conjugate of the major circulating clopidogrel metabolites, called clopidogrel acyl glucuronide (CAG), is already known. However, information regarding its pharmacokinetics (PK), metabolism, and clearance are modest. We investigated in vivo the potential CAG trans-esterification to clopidogrel (reaction occurring in vitro in particular conditions) by administering the metabolite to mice. Experiments were then carried out on men, clopidogrel administered alone or followed by activated charcoal intake (intestinal reabsorption blockade). Study objectives included: PK comparison of CAG, clopidogrel carboxylic acid (CCA), and clopidogrel in plasma, determination of their elimination patterns in urine and feces, and tracking of charcoal-induced changes in PK and/or urinary excretion that would indicate relevant enterohepatic recycling of CAG. In mice, CAG was rapidly hydrolyzed to CCA after oral administration, whereas by intravenous route metabolic conversion to CCA was delayed. No levels of clopidogrel were detected in mice plasma, excluding any potential trans-esterification or other form of back-conversion in vivo. PK experiments in man showed that CAG is hydrolyzed in the gastrointestinal tract (very low concentrations in feces), but there is no evidence of enterohepatic recirculation. Quantitation of the three moieties in stool samples accounted for only 1.2% of an administered dose, suggesting that other yet unknown metabolites/degradation products formed through metabolic processes and/or the activity of local microflora are mainly excreted by this route. In man CAG was confirmed as one of the major terminal metabolites of clopidogrel, with a PK behavior similar to CCA.