Cetirizine

Cetirizine, sold under the brand name Zyrtec and others, is an antihistamine medication used to treat allergies. It is taken by mouth. It starts working within an hour and it lasts for about a day.[5] It works as well as other antihistamines like diphenhydramine.[6]

Cetirizine
Systematic (IUPAC) name
(±)-[2-[4-[(4-Chlorophenyl)phenylmethyl]-1-piperazinyl]ethoxy]acetic acid
Identifiers
CAS number 83881-51-0
ATC code R06AE07 S01GX12
PubChem 2678
DrugBank DB00341
ChemSpider 2577
Chemical data
Formula C21H25Template:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxClTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxN2Template:OrganicBoxO3Template:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBoxTemplate:OrganicBox 
Mol. mass ?
Pharmacokinetic data
Bioavailability Well-absorbed (>70%)[1]
Protein binding 88–96%[1]
Metabolism Minimal (non-cytochrome P450-mediated)[2][3]
Half life Mean: 8.3 hours[2][3]
Range: 6.5–10 hours[4]
Excretion Urine: 70–85%[2]
Feces: 10–13%[2]
Therapeutic considerations
Licence data

US Daily Med:link

Pregnancy cat.

B2(AU)

Legal status

Unscheduled(AU) ?(CA) GSL(UK) OTC(US) OTC

Routes By mouth

Common side effects are sleepiness, dry mouth, headache, and a abdominal pain.[6] There is less sleepiness than in first generation antihistamines.[5] Pregnant women can use it, but not women who are breastfeeding.[7] It works by blocking histamine at H1 receptors, mostly outside of the brain.[6]

It was patented in 1981, and was first used in 1987.[8][9] It is on the World Health Organization's List of Essential Medicines.[10] It is available as a generic medication.[5] It was the 67th most commonly prescribed medication in the United States in 2019, with over 11 million prescriptions.[11][12]

Cetirizine Media

References

  1. 1.0 1.1 Chen C (2008). "Physicochemical, pharmacological and pharmacokinetic properties of the zwitterionic antihistamines cetirizine and levocetirizine". Curr. Med. Chem. 15 (21): 2173–91. doi:10.2174/092986708785747625. PMID 18781943.
  2. 2.0 2.1 2.2 2.3 Portnoy JM, Dinakar C (2004). "Review of cetirizine hydrochloride for the treatment of allergic disorders". Expert Opin Pharmacother. 5 (1): 125–35. doi:10.1517/14656566.5.1.125. PMID 14680442. S2CID 28946859.
  3. 3.0 3.1 Simons FE, Simons KJ (1999). "Clinical pharmacology of new histamine H1 receptor antagonists". Clin Pharmacokinet. 36 (5): 329–52. doi:10.2165/00003088-199936050-00003. PMID 10384858. S2CID 21360079.
  4. Simons FE (2002). "Comparative pharmacology of H1 antihistamines: clinical relevance". Am. J. Med. 113 Suppl 9A (9): 38S–46S. doi:10.1016/s0002-9343(02)01436-5. PMID 12517581.
  5. 5.0 5.1 5.2 British national formulary : BNF 76 (76 ed.). Pharmaceutical Press. 2018. p. 279. ISBN 9780857113382.
  6. 6.0 6.1 6.2 "Cetirizine Hydrochloride Monograph for Professionals". Drugs.com. American Society of Health-System Pharmacists. Retrieved 3 March 2019.
  7. "Cetirizine Pregnancy and Breastfeeding Warnings". Drugs.com. Retrieved 3 March 2019.
  8. Fischer, Jnos; Ganellin, C. Robin (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 549. ISBN 9783527607495.
  9. Baltes E, De Lannoy J, Rodriguez L, "2-[4-(Diphenylmethyl)-1-piperazinyl]-acetic acids and their amides", US patent 4525358, issued 25 June 1985
  10. World Health Organization (2021). World Health Organization model list of essential medicines: 22nd list (2021). Geneva: World Health Organization. hdl:10665/345533. WHO/MHP/HPS/EML/2021.02.
  11. "The Top 300 of 2019". ClinCalc. Retrieved 16 October 2021.
  12. "Cetirizine - Drug Usage Statistics". ClinCalc. Retrieved 16 October 2021.