Guanfacine

Guanfacine

Clinical data
Trade names	Afken, Estulic, Intuniv, Tenex
AHFS/Drugs.com	Monograph
MedlinePlus	a601059
License data	US DailyMed: 9fc0bdc2-5ba2-48dd-aa87-7b0050a2d6ce
Pregnancy category	US: B (No risk in non-human studies)
Routes of administration	oral, intravenous
ATC code	C02AC02 (WHO)
Legal status
Legal status	US: ℞-only
Pharmacokinetic data
Bioavailability	80-100% (IR), 58% (XR)
Protein binding	70%
Metabolism	CYP3A4
Biological half-life	IR: 10-17 hours; XR: 17 hours (10-30) in adults & adolescents and 14 hours in Paediatrics
Excretion	renal (80%; 50% [range: 40-75%] as unchanged drug)
Identifiers
IUPAC name N-(diaminomethylidene)-2-(2,6-dichlorophenyl)acetamide
CAS Number	29110-47-2 Y
PubChem (CID)	3519
IUPHAR/BPS	522
DrugBank	DB01018 Y
ChemSpider	3399 Y
UNII	30OMY4G3MK Y
KEGG	D08031 N
ChEMBL	CHEMBL862 Y
ECHA InfoCard	100.044.933
Chemical and physical data
Formula	C9H9Cl2N3O
Molar mass	246.093 g/mol
3D model (Jmol)	Interactive image
SMILES Clc1cccc(Cl)c1CC(=O)\N=C(/N)N
InChI InChI=1S/C9H9Cl2N3O/c10-6-2-1-3-7(11)5(6)4-8(15)14-9(12)13/h1-3H,4H2,(H4,12,13,14,15) Y Key:INJOMKTZOLKMBF-UHFFFAOYSA-N Y
NY (what is this?)

Guanfacine (brand name Estulic, Tenex and the extended release Intuniv) is a sympatholytic drug used in the treatment of attention deficit hyperactivity disorder (ADHD), anxiety and hypertension (not to be confused with guaifenesin, an expectorant). It is a selective α_2A receptor agonist. These receptors are concentrated heavily in the prefrontal cortex and the locus coeruleus, with the potential to improve attention resulting from interaction with receptors in the former. Guanfacine lowers both systolic and diastolic blood pressure by activating the central nervous system α_2A norepinephrine autoreceptors, which results in reduced peripheral sympathetic outflow and thus a reduction in peripheral sympathetic tone.

Guanfacine is currently approved and marketed in the United States and Europe as Intuniv for the treatment of ADHD in children and adolescents aged 6–18 years.

It has been shown to reduce hypertension not just in the short-term, but also in long-term studies to be able to achieve normalization in the blood pressure of 54% of patients treated over a year and 66% over two years. The average reduction in mean arterial pressure of all patients was 16% at the end of the first year and 17% at the end of the second year.

Guanfacine is used alone or with stimulants to treat children and teenagers with attention deficit hyperactivity disorder. Its effectiveness in this condition is likely due to its ability to strengthen prefrontal cortical regulation of attention and behavior.