Atomoxetine
Synonym :
Tomoxetine
Mechanism :
The precise mechanism by which atomoxetine produces its therapeutic effects in Attention-Deficit/Hyperactivity Disorder (ADHD) is unknown but is thought to be related to selective inhibition of the pre-synaptic norepinephrine transporter (Norepinephrine reuptake inhibitor).
Indication :
Contraindications :
Contraindicated in patients known to be hypersensitive to atomoxetine or other constituents of the product.
Should not be taken with an MAOI, or within 2 weeks after discontinuing an MAOI. Treatment with an MAOI should not be initiated within 2 weeks after discontinuing atomoxetine. Its use was associated with an increased risk of mydriasis and therefore its use is not recommended in patients with narrow angle glaucoma.
Dosing :
Initial 0.5 mg/kg/day orally, increase every 3rd day to a target total daily dose of approximately 1.2 mg/kg/day as a single daily dose or as evenly divided doses every 12 hourly. Max: 1.4 mg/kg or 100 mg.
Adverse Effect :
Aggression, irritability, somnolence, vomiting, dyspepsia, fatigue, decreased appetite, dizziness, xerostomia, cough and mood swings.
Interaction :
Albuterol: Should be administered with caution to patients being treated with systemically-administered (oral or intravenous) albuterol (or other beta2 agonists) because the action of albuterol on the cardiovascular system can be potentiated resulting in increases in heart rate and blood pressure.
CYP2D6 inhibitors: Atomoxetine is primarily metabolized by the CYP2D6 pathway to 4-hydroxyatomoxetine. Dosage adjustment may be necessary when coadministered with CYP2D6 inhibitors, e.g., paroxetine, fluoxetine, and quinidine.
Monoamine Oxidase Inhibitors: Should not be taken with an MAOI, or within 2 weeks after discontinuing an MAOI. Treatment with an MAOI should not be initiated within 2 weeks after discontinuing atomoxetine.
Pressor Agents: Because of possible effects on blood pressure, should be used cautiously with pressor agents.
Hepatic Dose :
Moderate hepatic impairment: Reduce initial and target dosage by 50%.
Severe hepatic impairment: Reduce initial and target dosage by 75%.