What is the mechanism of action of guanfacine?

Guanfacine's mechanism of action is primarily linked to its ability to stimulate postsynaptic α2-adrenergic receptors in the central nervous system (CNS). By activating these receptors, guanfacine results in decreased sympathetic outflow from the CNS, leading to a reduction in heart rate and blood pressure. This mechanism is particularly useful in treating conditions like hypertension and attention-deficit hyperactivity disorder (ADHD) by modulating the activity of noradrenergic pathways.

The stimulation of postsynaptic α2-adrenergic receptors also plays a role in enhancing prefrontal cortex function, which can be beneficial in the management of ADHD symptoms. Thus, the correct answer accurately reflects how guanfacine acts within the body to exert its therapeutic effects, focusing on adrenergic receptor interactions rather than neurotransmitter reuptake or inhibition.