Which non-stimulant ADHD medication is a selective alpha-2A agonist similar to clonidine?

• A. Atomoxetine
• B. Guanfacine
• C. Methylphenidate
• D. Amphetamine

Answer: (B)

Guanfacine is a non-stimulant ADHD medication that acts as a selective alpha-2A adrenergic receptor agonist, similar to clonidine. The alpha-2A receptors are found in the prefrontal cortex, a brain area crucial for attention, working memory, and impulse control. When these receptors are activated, they help strengthen the prefrontal circuits, improving executive function and reducing hyperactivity and impulsivity. Guanfacine’s selectivity for the alpha-2A subtype gives therapeutic benefits with fewer sedative effects compared to clonidine, and it is often formulated as an extended-release preparation for ADHD.

Atomoxetine works differently—it’s a norepinephrine reuptake inhibitor, which increases norepinephrine levels but does not stimulate alpha-2A receptors. Methylphenidate and amphetamine are stimulants that raise dopamine and norepinephrine through reuptake inhibition and release, not through alpha-2A receptor activation.