American Board of Psychiatry and Neurology (ABPN) Practice Exam 2025 – Comprehensive All-in-One Guide to Exam Success!

Bupropion is indeed not primarily metabolized by the CYP2D6 enzyme. Instead, it is mainly metabolized by CYP2B6. This distinction is crucial because the metabolic pathway affects how the drug is processed in the body, which can influence efficacy and the risk of side effects. While bupropion can inhibit CYP2D6, it does not rely on this enzyme for its own metabolism, making it unique among the options listed.

In contrast, the other substances mentioned are significantly metabolized by CYP2D6. For instance, aripiprazole, codeine, and duloxetine are all known to rely on the CYP2D6 pathway for their metabolism. Understanding which drugs are metabolized by specific enzymes is essential in clinical practice, especially when considering potential drug interactions and variations in patient responses due to genetic polymorphisms affecting enzyme activity.