Effect of Dexamethasone on CYP Enzyme Activity in Healthy Male Subjects

Purpose: The purpose of this study is to understand how dexamethasone affects the activity of drug-metabolizing enzymes in the body and how this may influence interactions with other medicines, such as voriconazole. Background: Many medicines are broken down in the body by enzymes called cytochrome P450 (CYP) enzymes. Differences in CYP enzyme activity between individuals can lead to variability in drug response and drug-drug interactions. Dexamethasone is known to affect CYP enzyme activity, and voriconazole is a medication that is metabolized by these enzymes. Participants: This study will include a total of 12 healthy adult male volunteers. Participants will be grouped based on their metabolic status, including 6 normal metabolizers (NM) and 6 poor metabolizers (PM). Interventions: Participants will receive a combination of probe drugs known as a CYP probe cocktail to assess baseline CYP enzyme activity. Dexamethasone will be administered, and the CYP probe cocktail will be given again to evaluate changes in enzyme activity. Voriconazole will be used to assess the potential for drug-drug interactions related to changes in CYP enzyme activity. Blood samples will be collected during the study. Outcome Measures: The main outcomes of this study are changes in blood concentrations of the probe drugs, which reflect changes in CYP enzyme activity, and comparisons of these changes between normal metabolizers and poor metabolizers. Hypothesis: The study hypothesizes that dexamethasone alters CYP enzyme activity and that the magnitude of this effect differs between normal metabolizers and poor metabolizers, potentially affecting the metabolism of drugs such as voriconazole.