Treatment of ADHD

Introduction to Treatment

The American Academy of Pediatrics recommends initiating treatment with a stimulant medication, specifically either methylphenidate or amphetamine, after a failed trial of atomoxetine, due to their higher efficacy rates and first-line treatment status for ADHD 1
Atomoxetine is a recommended treatment for ADHD, with a target dose of 1.2 mg/kg/day (maximum 1.4 mg/kg/day or 100 mg/day, whichever is lower) for optimal efficacy, as recommended by the American Academy of Pediatrics 1

Before proceeding to the next treatment option, it is crucial to confirm that the treatment trial was adequate, including ensuring proper dosing and adequate trial duration, as atomoxetine has a delayed onset of full therapeutic effect 1
Inadequate dosing, failing to reach the target dose of 1.2 mg/kg/day, may result in suboptimal efficacy, as recommended by the American Academy of Pediatrics 1

Methylphenidate or amphetamine formulations should be tried next, as they have larger effect sizes compared to non-stimulants 1
Patients with ADHD may respond to either amphetamine or methylphenidate with an overall very high response rate when both psychostimulants are tried 1
Atomoxetine has comparable efficacy to immediate-release methylphenidate, but is less effective than extended-release methylphenidate formulations and extended-release mixed amphetamine salts, as reported by the American Academy of Pediatrics 2

Alpha-2 adrenergic agonists (guanfacine or clonidine) can be considered when stimulants are contraindicated or not preferred, as they have a faster onset of action and may be helpful for patients with comorbid sleep disturbances 1
These medications can be used as adjunctive therapy to stimulant medications, increasing treatment effects and/or decreasing adverse effects of stimulants 1

For patients with tic disorders or Tourette's syndrome, alpha-2 agonists may be beneficial 1
For substance use disorders, non-stimulants remain preferred over stimulants 1
For anxiety disorders, consider alternative non-stimulants or careful stimulant trial 1
Atomoxetine may be preferred for patients with comorbid anxiety or tics, as recommended by the American Academy of Pediatrics 2

When switching to stimulants, monitor for cardiovascular effects, appetite changes, weight, sleep disturbances, emergence of tics, or worsening of anxiety 1
Pharmacological treatment should always be part of a comprehensive treatment plan that includes psychoeducation and psychosocial interventions, considering comorbid conditions that might affect treatment choice 1
Patients should be monitored closely for suicidal ideation, especially during the first few months of treatment, as well as for clinical worsening or unusual changes in behavior, as recommended by the American Academy of Pediatrics 1, 2
Monitoring for increased heart rate and blood pressure, as well as tracking height and weight in pediatric patients, is also recommended, as atomoxetine has been linked to growth delays in the first 1-2 years of treatment 2

Common adverse effects of atomoxetine include nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence, with most side effects being mild to moderate in severity 1, 2
Adverse effects may be more pronounced if dosage is increased too rapidly, and most side effects are mild to moderate and often transient, as recommended by the American Academy of Pediatrics 2
Patients with cardiac risk factors should be monitored closely, and an ECG and possible referral to a pediatric cardiologist should be considered before initiating treatment, as recommended by the American Academy of Pediatrics 2
Approximately 7% of the population are poor metabolizers of atomoxetine due to CYP2D6, which may lead to higher plasma levels and more side effects, and co-administration with CYP2D6 inhibitors should be avoided 1

The initial dose of atomoxetine should be 0.5 mg/kg/day, with a target dose of 1.2 mg/kg/day, and a maximum dose of 1.4 mg/kg/day or 100 mg/day, whichever is lower, as recommended by the American Academy of Pediatrics 1
The dose should be administered either as a single daily dose in the morning or divided into two evenly spaced doses (morning and late afternoon) 1
For patients with hepatic impairment, the dose should be reduced by 50%, and for CYP2D6 poor metabolizers or patients taking strong CYP2D6 inhibitors, slower titration and lower target dose may be required, as recommended by the American Academy of Pediatrics 1

Unlike guanfacine and clonidine, atomoxetine does not require tapering when discontinuing, and discontinuation is not associated with symptom rebound, as recommended by the American Academy of Pediatrics 2
A cross-tapering approach is recommended when switching from Adderall to atomoxetine to minimize withdrawal symptoms and maintain symptom control during the transition period, with a target dose of 1.2 mg/kg/day and a maximum dose of 1.4 mg/kg/day or 100 mg/day, whichever is lower, as recommended by the American Academy of Child and Adolescent Psychiatry 1