What happens to atomoxetine levels in a 2D6 poor metabolizer?

In individuals who are poor metabolizers of CYP2D6, the metabolism of atomoxetine is significantly impaired. CYP2D6 is responsible for the biotransformation of atomoxetine, and when this enzyme is less effective or absent, the drug cannot be metabolized at its usual rate. This results in higher plasma concentrations of atomoxetine because the drug remains in the system longer due to decreased clearance.

Consequently, for those designated as 2D6 poor metabolizers, atomoxetine reaches peak concentrations that are higher than what would be observed in individuals with normal CYP2D6 function. The therapeutic implications of this are essential; healthcare providers need to monitor dosing and potential side effects closely in these individuals since elevated levels could lead to increased adverse effects or toxicity. This understanding reinforces the importance of pharmacogenomics in guiding treatment decisions and customizing therapy for individuals based on their metabolic profiles.