Guanfacine

Not to be confused with Guanine, Guanosine, Guanidine, Guaifenesin, or Clonidine.

Guanfacine
Clinical data
Trade namesEstulic, Intuniv, Tenex, others
AHFS/Drugs.comMonograph
MedlinePlusa601059
License data
Routes of
administration		By mouth
Drug classCentrally acting α2A- adrenergic receptor agonist
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability80–100% (IR), 58% (XR)[5][6]
Protein binding70%[5][6]
MetabolismCYP3A4[5][6]
Elimination half-lifeIR: 10–17 hours; XR: 17 hours (10–30) in adults & adolescents and 14 hours in children[5][6][7][8]
ExcretionKidney (80%; 50% [range: 40–75%] as unchanged drug)[5][6]
Identifiers
  • N-(Diaminomethylidene)-2-(2,6-dichlorophenyl)acetamide
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.044.933 Edit this at Wikidata
Chemical and physical data
FormulaC9H9Cl2N3O
Molar mass246.09 g·mol−1
3D model (JSmol)
  • Clc1cccc(Cl)c1CC(=O)\N=C(/N)N
  • 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) checkY
  • Key:INJOMKTZOLKMBF-UHFFFAOYSA-N checkY
 ☒NcheckY (what is this?)  (verify)

Guanfacine, sold under the brand name Tenex (immediate-release) and Intuniv (extended-release) among others, is an oral alpha-2a agonist medication used to treat attention deficit hyperactivity disorder (ADHD) and high blood pressure.[3][9] Guanfacine is FDA-approved for monotherapy treatment of ADHD,[3] as well as being used for augmentation of other treatments, such as stimulants.[9] Guanfacine is also used off-label to treat tic disorders, anxiety disorders, and post-traumatic stress disorder (PTSD).[10]

Common side effects include sleepiness, constipation, and dry mouth.[9] Other side effects may include low blood pressure and urinary problems.[11] The FDA has categorized Guanfacine as "Category B" in pregnancy, which means animal-reproduction studies have not demonstrated a fetal risk or an adverse effect during pregnancy or breastfeeding.[12][11] It appears to work by activating α2A-adrenergic receptors in the brain, thereby decreasing sympathetic nervous system activity.[9]

Guanfacine was first described by 1974[13] and was approved for medical use in the United States in 1986.[9] It is available as a generic medication.[9] In 2021, it was the 231st most commonly prescribed medication in the United States, with more than 1 million prescriptions.[14][15]

  1. ^ "Prescription medicines: registration of new chemical entities in Australia, 2017". Therapeutic Goods Administration (TGA). 21 June 2022. Retrieved 9 April 2023.
  2. ^ "Prescription medicines and biologicals: TGA annual summary 2017". Therapeutic Goods Administration (TGA). 21 June 2022. Retrieved 31 March 2024.
  3. ^ a b c "Intuniv- guanfacine tablet, extended release Intuniv- guanfacine kit". DailyMed. 26 January 2021. Archived from the original on 6 August 2022. Retrieved 6 August 2022.
  4. ^ "Intuniv EPAR". European Medicines Agency. 17 September 2015. Retrieved 13 June 2024.
  5. ^ a b c d e "Guanfacine (guanfacine) Tablet [Genpharm Inc.]". DailyMed. Genpharm Inc. March 2007. Archived from the original on 26 June 2022. Retrieved 9 November 2013.
  6. ^ a b c d e "guanfacine (Rx) - Intuniv, Tenex". Medscape Reference. WebMD. Archived from the original on 18 May 2019. Retrieved 9 November 2013.
  7. ^ Hofer KN, Buck ML (2008). "New Treatment Options for Attention-Deficit/Hyperactivity Disorder (ADHD): Part II. Guanfacine". Pediatric Pharmacotherapy (14): 4. Archived from the original on 31 October 2015. Retrieved 30 July 2014.
  8. ^ Cruz MP (August 2010). "Guanfacine Extended-Release Tablets (Intuniv), a Nonstimulant Selective Alpha(2A)-Adrenergic Receptor Agonist For Attention-Deficit/Hyperactivity Disorder". P & T. 35 (8): 448–451. PMC 2935643. PMID 20844694.
  9. ^ a b c d e f "Guanfacine Monograph for Professionals". Drugs.com. American Society of Health-System Pharmacists. Archived from the original on 15 January 2018. Retrieved 18 March 2019.
  10. ^ Boland RJ, Verduin ML, Sadock BJ (2023). Ruiz P (ed.). Kaplan & Sadock's Concise Textbook of Clinical Psychiatry (5th ed.). Philadelphia: Wolters Kluwer. pp. 1811–1812. ISBN 978-1-9751-6748-6. OCLC 1264172789. Archived from the original on 8 February 2023. Retrieved 12 January 2023.
  11. ^ a b British national formulary: BNF 76 (76 ed.). Pharmaceutical Press. 2018. pp. 349–350. ISBN 978-0-85711-338-2.
  12. ^ "Patient Information. INTUNIV (in-TOO-niv) (guanfacine). Extended-Release Tablets" (PDF). FDA.gov. Archived (PDF) from the original on 13 October 2022. Retrieved 12 October 2022.
  13. ^ Cite error: The named reference Turner1974 was invoked but never defined (see the help page).
  14. ^ "The Top 300 of 2021". ClinCalc. Archived from the original on 15 January 2024. Retrieved 14 January 2024.
  15. ^ "Guanfacine - Drug Usage Statistics". ClinCalc. Retrieved 14 January 2024.