CYP2D6 substrates Atomoxetine

Desipramine is extensively metabolised by CYP2D6, and can be used as a probe drug for assessment of the effect of drugs on this isoenzyme in extensive metabolisers (see Genetic factors , (p.4)). It was concluded that atomoxetine, even at the maximum recommended dose, does not cause clinically relevant inhibition of CYP2D6 in vivo, and so will not affect the pharmacokinetics of other CYP2D6 substrates. For a list of C YP2D6 substrates, see Table 1.3 , (p.6). 

Initiate therapy of these drugs, particularly those with a narrow therapeutic index, at the lowest effective dose. Interaction is likely to be important with substrates for which CYP2D6 is considered the only metabolic pathway (e.g. hydrocodone, oxycodone, desipramine, paroxetine, chlorpheniramine, mesoridazine, alprenolol, amphetamines, atomoxetine)... 

Atomoxetine did not aiter desipramine pharmacokinetics and wouid therefore not be expected to affect other substrates of CYP2D6. Atomoxetine did not aiter midazolam pharmacokinetics and wouid therefore not be expected to affect other substrates of CYP3A4. Antacids and omeprazole do not alter atomoxetine bioavaiiabiiity. 

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