Guanfacine an Inattentive ADHD Treatment That is Not a Simulant

In November of this year the pharmaceutical company, Shire, released the first long acting alpha2 receptor specifically marketed to treat ADHD. The name they gave this medicine is Intuniv (Guanfacine, long acting).

Alpha2 receptor medications have been used in addition to the stimulants for a while. Tenex is the medicine most commonly used. Tenex (Guanfacine) is a blood pressure medicine that was coincidentally found to help patients with ADHD including patients with Inattentive ADHD. Tenex can be sedating and doctors have used it to help with the 'crash' experienced by some patients when stimulant medicines wear off.

The science of these medications is relativley new but some researchers believe that it is the alpha2 receptor drugs, and not the stimulants, that better target the symptoms of inattention, impulsivity, and working memory defecits. They believe that while the stimulants work they do not address the underlying problem at the Prefrontal Cortex.

The medicines act on the Prefrontal Cortex (PFC), the area of the brain that controls attention, impulsivity, hyperactivity, and working memory. Studies done on Monkeys showed that blockage of the alpha2 receptors in the monkey's PFC recreated the symptoms of ADHD, resulting in impaired working memory, increased impulsivity, and locomotor hyperactivity.

Alpha-2A adrenergic receptors also improve brain communication. These receptors are stimulated by guanfacine which strengthens the connectivity of PFC networks and improves working memory and reduces distractibility.

Unlike the stimulants, Guanfacine provides these benefits to the PFC even in the event of stress. Stress has been shown to temporarily disconnect networks which can make the symptoms of  Inattentive ADHD much worse.

Perhaps the most exiting findings with regards to treatment is the fact that it also helped patients with Inattentive ADHD.

Who knows?? Guanfacine may turn out to be the future 'gold standard' of treatment for the symptoms of  Inattentive ADHD. Time will tell.....

Behav Brain Funct. 2008 Feb 28;4:12.
Pharmacological and therapeutic directions in ADHD: Specificity in the PFC.
Levy F.
School of Psychiatry, University of New South Wales, Prince of Wales Hospital, Sydney, NSW 2031, Australia. f.levy@unsw.edu.au.

Ann N Y Acad Sci. 2008;1129:236-45.
Neuronal mechanisms underlying attention deficit hyperactivity disorder: the influence of arousal on prefrontal cortical function.
Brennan AR, Arnsten AF.
Department of Neurobiology, Yale University School of Medicine, New Haven, CT 06510, USA