CYP2D6 inhibitors Atomoxetine

Concomitant use In children up to 70 kg body weight administered strong CYP2D6 inhibitors, initiate atomoxetine at 0.5 mg/kg/day and only increase to the usual target dose of 1.2 mg/kg/day if symptoms fail to improve after 4 weeks and the initial dose is well-tolerated. 

Drugs that may interact with atomoxetine include albuterol, CYP2D6 inhibitors, MAOIs, and pressor agents. 

In EMs, inhibitors of CYP2D6 increase atomoxetine steady-state plasma concentrations to exposures similar to those observed in PMs. Dosage adjustment of STRATTERA in EMs may be necessary when coadministered with CYP2D6 inhibitors, e.g., paroxetine, fluoxetine, and quinidine (see Dmg Interactions and PRECAUTIONS). In vitro studies suggest that coadministration of cytochrome P450 inhibitors to PMs will not increase the plasma concentrations of atomoxetine. 

Paroxetine markedly increases atomoxetine levels in extensive metabolisers of CYP2D6. Fluoxetine also raises atomoxetine levels. There is a possibility that this may increase adverse effects, and a slower titration of atomoxetine dose is su ested for patients taking paroxetine and other CYP2D6 inhibitors. 

SSRIs ATOMOXETINE t plasma concentrations and risk of adverse effects (abdominal pain, vomiting, nausea, fatigue, irritability) Atomoxetine is a selective norepinephrine reuptake inhibitor, t plasma concentrations due to inhibition of CYP2D6 by fluoxetine and paroxetine (potent), fluvoxamine and sertraline (less potent) and escitalopram and citalopram (weak) Avoid concurrent use. The interaction is usually severe with fluoxetine and paroxetine... 

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