Guanfacine Hcl Er (guanfacine HCl)

Guanfacine is a phenylacetyl-guanidine derivative hypotensive agent; the drug is a selective alpha2-adrenergic agonist.

Guanfacine appears to stimulate alpha2-adrenergic receptors in the CNS, causing inhibition of sympathetic vasomotor centers; this contributes predominantly to the hypotensive effects of the drug. Central effects of the drug result in reduced peripheral sympathetic nerve impulses from the vasomotor center to the heart and blood vessels, resulting in a decrease in peripheral vascular resistance and a reduction in heart rate. Under conditions of rest or exercise, cardiac output is not altered.

Guanfacine reduces blood pressure in both supine and standing positions; hypotensive effects may be somewhat greater in the standing position. Peripheral effects (stimulation of peripheral alpha2-adrenergic receptors) also may contribute to the drug's hypotensive effects.

Guanfacine lowers elevated plasma renin activity and plasma catecholamine concentrations in patients with hypertension, although these effects do not correlate with individual hypotensive responses.

Acute administration of guanfacine stimulates release of growth hormone, but the drug does not produce sustained elevation of growth hormone during chronic administration. Guanfacine does not affect plasma aldosterone, mean body weight, or electrolytes; a slight but insignificant increase in plasma volume is observed after 1 month of therapy. The drug reduces serum prolactin concentrations in hypertensive patients with elevated serum prolactin concentrations.

Guanfacine enhances neurologic activity in the prefrontal cortex, an area of the brain involved in planning, impulse control, and organization. The drug has been shown in nonhuman primates to improve prefrontal cortical function through direct action on postsynaptic alpha2A-adrenergic receptors located in the prefrontal cortex. Sedative effects, which are less severe than those seen with clonidine, are the result of inhibitory effects on noradrenergic locus ceruleus neurons and direct effects on the thalamus.

USES: This medication is used to treat attention deficit hyperactivity disorder (ADHD), as part of a total treatment plan including psychological, educational, and social measures. Unlike other drugs used to treat ADHD, guanfacine is not a stimulant. The exact way that guanfacine works to treat ADHD is unknown.

Guanfacine is thought to affect receptors in the parts of the brain that lead to strengthening working memory, reducing distraction, and improving attention and impulse control. Guanfacine may help lessen ADHD symptoms such as being disruptive, inattentive, hyperactive, impulsive, and arguing with adults or losing one's temper.

Generic name: guanfacine HCl
Pronunciation: (GWAN-fuh-seen)

The following indications are listed for Guanfacine Hcl Er:

• Attention-Deficit Hyperactivity Disorder

Also known as: Add With Hyperactivity.

No ICD codes are available for this drug.