Potential interactions of methylphenidate and atomoxetine with dextromethorphan.

Objective: To examine the potential for drug-drug interactions to influence drug metabolism between the attention-deficit/hyperactivity disorder (ADHD) dl-methylphenidate and atomoxetine with dextromethorphan, a probe for interactions involving cytochrome P450 (CYP) 2D6 isoenzyme.

Design: In vitro and ex vivo analysis of changes in metabolism of study drugs.

Setting: Laboratory.