Complex sentence: In one study, reboxetine was shown to have no metabolic interactions with a drug that is a substrate for CYP2D6, in dextromethorphan, in contrast to paroxetine-which exhibited significant inhibition on CYP2D6, and thus significant metabolic variations in dextromethorphan processing.
Split into simpler sentences: In one study, reboxetine was shown to have no metabolic interactions with a drug that is a substrate for CYP2D6, in dextromethorphan. In contrast to paroxetine-which exhibited significant inhibition on CYP2D6, and thus significant metabolic variations in dextromethorphan processing.