atomoxetine hydrochloride: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
atomoxetine hydrochloride: clinical details
Prescribing considerations
- Initiation should be by an ADHD specialist following diagnostic and functional assessment; adult symptoms originating in childhood should be verified.
- Obtain cardiovascular history and examination before treatment, with specialist cardiac assessment if findings suggest disease.
- Review hepatic impairment, seizure history, QT risk, urinary retention, psychiatric comorbidity and concomitant CYP2D6 inhibitors.
- CYP2D6 poor metabolisers have substantially greater exposure and may experience more adverse effects.
Contraindications and cautions
- Hypersensitivity to atomoxetine or an excipient
- Concomitant or insufficiently separated MAOI treatment
- Narrow-angle glaucoma
- Severe cardiovascular or cerebrovascular disorders
- Phaeochromocytoma or a history of phaeochromocytoma
Monitoring
- Record blood pressure and pulse before treatment, after treatment adjustments and at least every 6 months.
- Monitor height, weight and development in children and adolescents.
- Monitor for suicidality, aggression, emotional lability, psychotic or manic symptoms, depression, anxiety and tics.
- Investigate symptoms suggesting cardiac or hepatic injury promptly; do not restart after jaundice or laboratory-confirmed liver injury.
Clinical pharmacology
Atomoxetine is a selective presynaptic noradrenaline-transporter inhibitor. It is absorbed orally, highly protein bound and metabolised mainly through CYP2D6; reduced CYP2D6 activity markedly increases exposure and prolongs elimination.
Formulation and product differences
- Hard capsules must be swallowed whole and not opened because their contents are an ocular irritant.
- The oral solution uses an oral syringe and bottle adaptor and should not be mixed with food or water.
- The oral solution contains sorbitol and is unsuitable for hereditary fructose intolerance; it also contains sodium benzoate, propylene glycol and sodium.
- Discard the oral solution 45 days after first opening.
- Capsules and oral solution are bioequivalent.
atomoxetine hydrochloride preparations and strengths
Capsule
Route: Oral
Strengths: 10 mg, 18 mg, 25 mg, 40 mg, 60 mg, 80 mg, 100 mg
atomoxetine hydrochloride interactions
Check prescribed, over-the-counter and herbal products with a pharmacist or prescriber. Important interactions include:
Monoamine oxidase inhibitors (MAOIs)
Must not be combined with atomoxetine; a washout period is required when changing between them.
Strong CYP2D6 inhibitors, including fluoxetine, paroxetine, quinidine and terbinafine
Can substantially increase atomoxetine exposure, requiring reassessment of response and tolerability.
Serotonergic medicines, including SSRIs, SNRIs, some opioids and tricyclic antidepressants
May increase the risk of serotonin syndrome.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.