RT Journal Article SR Electronic T1 In Vitro and In Vivo Mechanistic Studies toward Understanding the Role of 1-Aminobenzotriazole in Rat Drug-Drug Interactions JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 1960 OP 1965 DO 10.1124/dmd.115.066357 VO 43 IS 12 A1 Marc-Olivier Boily A1 Nathalie Chauret A1 Julie Laterreur A1 François A. Leblond A1 Chantal Boudreau A1 Marie-Claude Duquet A1 Jean-François Lévesque A1 Line Ste-Marie A1 Vincent Pichette YR 2015 UL http://dmd.aspetjournals.org/content/43/12/1960.abstract AB 1-Aminobenzotriazole (ABT) is regularly used in vivo as a nonspecific and irreversible cytochrome P450 inhibitor to elucidate the role of metabolism on the pharmacokinetic profile of xenobiotics. However, few reports have considered the recent findings that ABT can alter drug absorption or have investigated the possible differential inhibition of ABT on intestinal and hepatic metabolism. To address these uncertainties, pharmacokinetic studies under well controlled and defined ABT pretreatment conditions (50 mg/kg, 1 hour ABT i.v. and 16 hours ABT p.o.) were conducted prior to the oral administration of metoprolol, a permeable P450 probe that undergoes extensive intestinal and hepatic metabolism. The pharmacokinetic profile of metoprolol was affected differently by the two ABT pretreatments. An increase in area under the curve of 16-fold with ABT p.o. and 6.5-fold with ABT i.v. was observed compared with control. Based on in vitro studies, this difference could not be attributed to a differential inhibition of intestinal and hepatic metabolism. In the ABT i.v. pretreatment group, the increase in area under the curve was also associated with a prolonged time at maximal concentration (24-fold versus control), suggesting a delay in absorption. This was further confirmed by the administration of a charcoal meal, which resulted in a 7-fold increase in stomach weights in the 1-hour ABT pretreated groups compared with the untreated or 16-hour ABT pretreated rats. Based on these results, we recommend pretreating rats with ABT p.o. 16 hours before the administration of a test compound to preserve the inhibitory effect on intestinal and hepatic metabolism and avoid the confounding effect on drug absorption.