guanfacin

Guanfacine, sometimes spelled guanfacine, is a prescription medication that acts as an alpha-2A adrenergic receptor agonist. It is available in immediate-release and extended-release formulations and is sold under brand names including Tenex (immediate-release) and Intuniv (extended-release). The drug is used to treat hypertension and, in its extended-release form, attention-deficit/hyperactivity disorder (ADHD) in children and adolescents. It is sometimes used off-label for other conditions, but its primary approved indications are blood pressure reduction and ADHD symptom management.

In hypertension, guanfacine lowers blood pressure by decreasing sympathetic nerve activity, which reduces peripheral vascular resistance. In ADHD, the extended-release formulation is believed to improve prefrontal cortex function and executive control through selective alpha-2A receptor stimulation, contributing to improved attention and reduces hyperactive-impulsive behavior. Response in ADHD typically requires several weeks of consistent dosing.

Administration and dosing are individualized. Extended-release guanfacine is taken once daily, swallowed whole, and dosing is titrated based on response and tolerability. Immediate-release guanfacine is taken in divided doses. It is important to avoid abrupt discontinuation, as stopping guanfacine suddenly can cause rebound hypertension and other withdrawal symptoms.

Common side effects include drowsiness, fatigue, dizziness, and low blood pressure. Less frequent effects may include dry mouth, constipation, or mood changes. Caution is advised when combining with other central nervous system depressants, alcohol, or other antihypertensives. Possible interactions with certain antidepressants and MAO inhibitors should be discussed with a healthcare provider.