What effect does fluconazole have when given to someone on methadone?

Fluconazole can lead to increased methadone levels in individuals due to its role as a potent inhibitor of the cytochrome P450 enzyme CYP3A4. Methadone is metabolized primarily through this enzyme, and when fluconazole is administered, it interferes with the metabolism of methadone. This inhibition means that the body is less able to break down methadone, leading to an accumulation of the drug in the bloodstream and potentially increasing its effects and side effects.

Understanding the mechanism is vital in clinical practice, especially in managing patients who are on methadone maintenance therapy. The combination of fluconazole and methadone requires careful monitoring for potential overdose or increased adverse effects due to elevated methadone levels. This interaction highlights the importance of considering drug interactions and the metabolic pathways involved in medication management for patients with substance use disorders.