Generic Name and Formulations:
Guanfacine (as HCl) 1mg, 2mg, 3mg, 4mg; ext-rel tabs.
Shire US, Inc.
Attention deficit hyperactivity disorder (ADHD), as monotherapy or as an adjunct to stimulant medications.
≥18yrs: not established.
Swallow whole with water, milk, or other liquid. Do not give with high-fat meals. <6yrs: not established. 6–17yrs: Initially 1mg once daily; adjust in increments of no more than 1mg/week; usual range: 1–4mg once daily. Doses >4mg/day: not studied. Mono- and adjunctive therapy: improvements seen at doses of 0.05–0.08mg/kg once daily; doses up to 0.12mg/kg once daily may provide additional benefit. Reevaluate periodically. Withdraw gradually (by 1mg every 3–7 days).
Central alpha-2A agonist.
Concomitant use with other forms of guanfacine.
Do not substitute with other forms of guanfacine on a mg-mg basis. Concomitant antihypertensives, other risks for hypotension, syncope, bradycardia, cardiovascular disease. Monitor heart rate, BP. Dehydration. Elevated temperature. Renal or hepatic impairment. Pregnancy (Cat.B). Nursing mothers.
Avoid with alcohol. May be potentiated by CYP3A4/5 inhibitors (eg, ketoconazole). May be antagonized by CYP3A4 inducers (eg, rifampin). May potentiate valproic acid. Additive effects with other antihypertensives, CNS depressants (eg, benzodiazepines, antipsychotics, barbiturates).
Somnolence, sedation, fatigue, nausea, lethargy, hypotension, insomnia, dizziness, abdominal pain, dry mouth, constipation; bradycardia.