A centrally acting antihypertensive agent. The drug lowers both systolic and diastolic blood pressure by activating the central nervous system alpha-2 adrenoreceptors, which results in reduced sympathetic outflow leading to reduced vascular tone. Its adverse reactions include dry mouth, sedation, and constipation. [PubChem]
Indication
For use alone or in combination with other classes of antihypertensive agents in the management of hypertension. Has also been used for the treatment of attention deficit hyperactivity disorder (ADHD) in pediatric patients.
Pharmacology
Guanfacine is a phenylacetyl-guanidine derivative hypotensive and a centrally-acting, alpha(2)-adrenergic receptor agonist used alone or in combination with other drugs for the treatment of hypertension.
Toxicity
Symptoms of overdose include drowsiness, lethargy, bradycardia and hypotension. LD50=165mg/kg (orally in mice)
Affected Organisms
Humans and other mammals
Biotransformation
Hepatic
Absorption
Rapid and complete, with an oral bioavailability of approximately 80%.
Half Life
17 hours (range 10-30 hours)
Protein Binding
Approximately 70% bound to plasma proteins, independent of drug concentration.
Elimination
In individuals with normal renal function, guanfacine and its metabolites are excreted primarily in the urine.
