MDMA (ecstasy) inhibits two key liver enzymes, CYP2D6 and CYP3A4, that metabolize the antidepressant mirtazapine (MRZ). In an isolated perfused rat liver model, animals given MDMA before MRZ showed 80% higher parent drug concentrations and 50% lower concentrations of both major metabolites (8-hydroxymirtazapine and N-desmethylmirtazapine) compared to controls. The area under the curve for the parent drug increased by 50%, while those for the metabolites decreased by 70% and 60%, respectively. Hepatic clearance dropped by 20% and intrinsic clearance by 60%. These findings indicate that ecstasy consumption can substantially alter MRZ metabolism, potentially affecting its efficacy and safety.
A single dose of MDMA (ecstasy) inhibits the liver enzyme CYP2D6, but the duration of inhibition depends on the concentration of the probe drug used to measure enzyme activity. Using a therapeutic concentration of dextromethorphan (2 µM), enzyme activity was significantly reduced only at 1 hour after MDMA, with recovery by 1 week. Using a saturated concentration (300 µM), activity was reduced at 1 hour, 1 week, and 1 month. The results suggest that the apparent recovery time of CYP2D6 after MDMA exposure varies with probe concentration, likely due to differences in metabolic pathways at different substrate levels.