Guanfacine

Guanfacine (brand name Estulic, Tenex and the extended release Intuniv) is a sympatholytic drug used in the treatment of attention deficit hyperactivity disorder (ADHD) and hypertension (not to be confused with guaifenesin, an expectorant). It is a selective α_2A receptor agonist. These receptors are concentrated heavily in the prefrontal cortex and the locus coeruleus, with the potential to improve attention resulting from interaction with receptors in the former. Guanfacine lowers both systolic and diastolic blood pressure by activating the central nervous system α_2A norepinephrine autoreceptors, which results in reduced peripheral sympathetic outflow and thus a reduction in peripheral sympathetic tone.

Guanfacine is currently approved and marketed in the United States and Europe as Intuniv for the treatment of ADHD in children and adolescents aged 6–18 years.

Medical uses

Hypertension

It has been shown to reduce hypertension not just in the short-term, but also in long-term studies to be able to achieve normalization in the blood pressure of 54% of patients treated over a year and 66% over two years. The average reduction in mean arterial pressure of all patients was 16% at the end of the first year and 17% at the end of the second year.