Guanfacine and Clonidine for ADHD in Children: Key Considerations

Clinical Efficacy and Dosing

The American Academy of Child and Adolescent Psychiatry recommends guanfacine as a viable treatment option for ADHD symptoms, with clonidine typically requiring divided dosing, in a study published in the Journal of the American Academy of Child and Adolescent Psychiatry in 2014 1
Clonidine may be considered when guanfacine has failed or caused intolerable side effects, and more immediate behavioral control is needed, with dosing recommendations including starting with 0.1 mg at bedtime and titrating to a maximum of 0.4 mg/day, as per the Journal of the American Academy of Child and Adolescent Psychiatry in 2014 1

The American Academy of Child and Adolescent Psychiatry notes that clonidine causes hypotension and drowsiness as primary side effects, with guanfacine having a more favorable side effect profile, as reported in the Journal of the American Academy of Child and Adolescent Psychiatry in 2014 1

The American Academy of Child and Adolescent Psychiatry suggests choosing guanfacine as first-line alpha-2 agonist when sedation is a concern, once-daily dosing is preferred, and patient has cardiovascular risk factors, as per the Journal of the American Academy of Child and Adolescent Psychiatry in 2014 1

Guanfacine has higher specificity for alpha-2A receptors compared to clonidine, which explains its different adverse effect profile (less sedation) 2, 3
Guanfacine is approximately ten times less potent than clonidine but has greater selectivity for alpha-2A receptors 2
The drug is primarily metabolized via CYP3A4 and excreted predominantly through renal pathways 2

The therapeutic effects of guanfacine in ADHD are not immediate and typically take 2-4 weeks to become apparent, unlike stimulants which have a more rapid onset 4
Guanfacine provides "around-the-clock" effects compared to stimulant medications 4
Guanfacine has been shown to improve functional impairment and quality of life in ADHD patients 4

Guanfacine is available in tablet form with doses of 1, 2, 3, and 4 mg, with dosing typically adjusted to body weight (0.1 mg/kg as a rule of thumb) 2, 5
Warnings exist regarding hypotension/bradycardia, somnolence/sedation, discontinuation effects, and cardiac conduction abnormalities 2, 3
The medication should be tapered rather than suddenly discontinued to avoid withdrawal effects 3, 5