Screening of 16 major drug glucuronides for time-dependent inhibition of nine drug-metabolizing CYP enzymes - detailed studies on CYP3A inhibitors

Helinä Kahma; Marie-Noëlle Paludetto; Mikko Neuvonen; Mika Kurkela; Anne M Filppula; Mikko Niemi; Janne T Backman

doi:10.1016/j.ejps.2024.106735

Screening of 16 major drug glucuronides for time-dependent inhibition of nine drug-metabolizing CYP enzymes - detailed studies on CYP3A inhibitors

Eur J Pharm Sci. 2024 Feb 27:106735. doi: 10.1016/j.ejps.2024.106735. Online ahead of print.

Authors

Helinä Kahma¹, Marie-Noëlle Paludetto¹, Mikko Neuvonen¹, Mika Kurkela¹, Anne M Filppula², Mikko Niemi³, Janne T Backman⁴

Affiliations

¹ Department of Clinical Pharmacology, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
² Department of Clinical Pharmacology, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
³ Department of Clinical Pharmacology, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Department of Clinical Pharmacology, HUS Diagnostic Center, Helsinki University Hospital, Helsinki, Finland.
⁴ Department of Clinical Pharmacology, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Department of Clinical Pharmacology, HUS Diagnostic Center, Helsinki University Hospital, Helsinki, Finland. Electronic address: janne.backman@helsinki.fi.

PMID: 38423227
DOI: 10.1016/j.ejps.2024.106735

Abstract

Time-dependent inhibition of cytochrome P450 (CYP) enzymes has been observed for a few glucuronide metabolites of clinically used drugs. Here, we investigated the inhibitory potential of 16 glucuronide metabolites towards nine major CYP enzymes in vitro. Automated substrate cocktail methods were used to screen time-dependent inhibition of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2J2 and 3A in human liver microsomes. Seven glucuronides (carvedilol β-D-glucuronide, diclofenac acyl-β-D-glucuronide, 4-hydroxyduloxetine β-D-glucuronide, ezetimibe phenoxy-β-D-glucuronide, raloxifene 4'-glucuronide, repaglinide acyl-β-D-glucuronide and valproic acid β-D-glucuronide) caused NADPH- and time-dependent inhibition of at least one of the CYPs investigated, including CYP2A6, CYP2C19 and CYP3A. In more detailed experiments, we focused on the glucuronides of carvedilol and diclofenac, which inhibited CYP3A. Carvedilol β-D-glucuronide showed weak time-dependent inhibition of CYP3A, but the parent drug carvedilol was found to be a more potent inhibitor of CYP3A, with the half-maximal inhibitor concentration (IC₅₀) decreasing from 7.0 to 1.1 µM after a 30-minute preincubation with NADPH. The maximal inactivation constant (k_inact) and the inhibitor concentration causing half of k_inact (K_I) for CYP3A inactivation by carvedilol were 0.051 1/min and 1.8 µM, respectively. Diclofenac acyl-β-D-glucuronide caused time-dependent inactivation of CYP3A at high concentrations, with a 4-fold IC₅₀ shift (from 400 to 98 µM after a 30-minute preincubation with NADPH), and K_I and k_inact values of >2000 µM and >0.16 1/min. In static predictions, carvedilol caused significant (>1.25-fold) increase in the exposure of the CYP3A substrates midazolam and simvastatin. In conclusion, we identified several glucuronide metabolites with CYP inhibitory properties. Based on detailed experiments, the inactivation of CYP3A by carvedilol may cause clinically significant drug-drug interactions.

Keywords: CYP3A; Cytochrome P450; glucuronide metabolites; in vitro-in vivo predictions; metabolic drug-drug interactions; substrate cocktail; time-dependent inhibition.