Atomoxetine

The most frequently reported side effect, particularly in children. Usually improves over the first few weeks. Taking with food may help. Can be dose-limiting in some patients.

Clinically significant appetite suppression occurs but is generally milder than with stimulants. Monitor weight in children and adolescents.

Some patients experience activation and insomnia; others experience drowsiness. Dosing time can be adjusted accordingly (morning if sedating, evening if activating, though morning dosing is standard).

Noradrenergic effect. Usually mild and tolerable.

Noradrenergic effect on bladder sphincter tone. May be more clinically significant in adults with prostatic hypertrophy.

Expected pharmacological effect of increased noradrenergic tone. Usually clinically insignificant at standard doses. Screen for cardiac risk factors before starting.

Some patients report emotional lability, irritability, or mood swings. Monitor, particularly in children and adolescents.

Statistically small increased risk in pediatric clinical trials. Monitor closely during the first few months and with dose changes. Communicate the warning to families. The risk is real but the absolute incidence is low.

Postmarketing reports of serious liver injury. Discontinue immediately if signs of hepatic dysfunction develop (jaundice, dark urine, pruritus, RUQ pain, flu-like symptoms with hepatic tenderness). Do not rechallenge after hepatotoxicity. Routine liver function monitoring is not required in the absence of symptoms, but clinical vigilance is necessary.

Decreased libido, erectile dysfunction, and ejaculatory difficulties have been reported, likely related to noradrenergic effects. Less well-studied than SSRI-related sexual dysfunction.