Atomoxetine (Straterra)

Antidepressant structure (norepinephrine reuptake inhibitor)

Dosing

Adults: 40-100mg/d. Start 40mg 1 qd x7days then 2 qd (take after dinner to reduce nausea). Improvement in ADHD is gradual over 2-3 weeks.

Children: <70 kg: Start 0.5 mg/kg QAM for three days, ↑ to 1.2 mg/kg QAM; may ↑ to max 1.4 mg/kg/day or 100 mg/day (whichever is less) after two to four weeks if needed; may divide doses >0.5 mg/kg.

QD and BID dosing are equally effective, but BID dosing has better GI tolerability.

INTERACTIONS: Levels are 10-fold higher with strong CYP2D6 inhibitors and poor metabolizers (caution with asenapine, bupropion, cannabidiol, duloxetine, and non-pram SSRIs: fluoxetine, paroxetine, sertraline ≥ 150 mg/day)

Management

Developed as a noradrenergic antidepressant but did not work in depression, although does help ADHD with anxiety. About half as effective as stimulants and slightly less effective than viloxazine (Qelbree), although viloxazine actually works in depression. Avoid in bipolar.

Benefits build up gradually over 4 weeks.

Like stimulants, has cardiotoxic effects so avoid combining with them (better to combine with alpha-agonists that do the opposite to the heart). Levels get extremely high in slow CYP 2D6 metabolizers and those taking CYP 2D6 inhibitors (like many antidepressants), causing extreme fatigue and possibly QTc prolongation.

TOLERABILITY: Headache, abdominal pain, decreased appetite, fatigue, nausea, erectile dysfunction, fatigue, insomnia.

RISKS: Hypertension, tachycardia, QTc prolongation, hepatitis, urinary hesitation.

EMR Text