Cetirizine: Difference between revisions

(494 intermediate revisions by more than 100 users not shown)

Line 1:

{{Drugbox

| verifiedrevid = 443512033

| IUPAC_name = (±)-[2-[4-[(4-chlorophenyl)phenylmethyl]-1- piperazinyl]ethoxy]acetic acid

{{Infobox drug

| image = Cetirizine structure.svg

| Watchedfields = changed

| imagename = Cetirizine

| verifiedrevid = 460026203

| drug_name = Cetirizine

| image = Cetirizine structure.svg

| width = 250

| tradename = Zyrtec

| image2 = Cetirizine-ball-and-stick.png

| Drugs.com = {{drugs.com|monograph|cetirizine-hydrochloride}}

| width2 = 250

| MedlinePlus = a698026

| caption =

| licence_EU =

| licence_US = Cetirizine

| pregnancy_US = B

| legal_UK = GSL

| legal_US = OTC

| legal_status = OTC in Canada

| routes_of_administration = Oral

| pronounce = {{IPAc-en|s|ɛ|ˈ|t|ɪr|ᵻ|z|iː|n}}

| bioavailability = well absorbed

| tradename = Allacan, Piriteze, Zyrtec, others

| protein_bound = ~93%

| Drugs.com = {{drugs.com|monograph|cetirizine-hydrochloride}}

| metabolism = Excreted mainly unchanged

| MedlinePlus = a698026

| elimination_half-life = 8.3 Hours

| DailyMedID = Cetirizine

| excretion = Urine (mainly), hepatic or excrement (Small amounts)

| pregnancy_AU = B2

| pregnancy_AU_comment =

| pregnancy_category =

| routes_of_administration = [[Oral administration|By mouth]]

| class =

| ATCvet =

| ATC_prefix = R06

| ATC_suffix = AE07

| ATC_supplemental = {{ATC|S01|GX12}}

| legal_AU = Unscheduled

| CASNo_Ref = {{cascite|correct|CAS}}

| legal_AU_comment =

| CAS_number = 83881-51-0

| legal_BR =

| ATC_prefix = R06

| legal_BR_comment =

| ATC_suffix = AE07

| legal_CA = OTC

| PubChem = 2678

| legal_CA_comment =

| IUPHAR_ligand = 1222

| legal_DE =

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| legal_DE_comment =

| DrugBank = DB00341

| legal_NZ = OTC

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| legal_NZ_comment =

| ChemSpiderID = 2577

| legal_UK = GSL

| UNII_Ref = {{fdacite|correct|FDA}}

| legal_UK_comment = / P

| UNII = YO7261ME24

| legal_US = OTC

| KEGG_Ref = {{keggcite|correct|kegg}}

| legal_US_comment = / Rx-only

| KEGG = D07662

| legal_EU =

| ChEBI_Ref = {{ebicite|correct|EBI}}

| legal_EU_comment =

| ChEBI = 3561

| legal_UN =

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| legal_UN_comment =

| ChEMBL = 1000

| legal_status = OTC / Rx-only

| bioavailability = Well-absorbed (>70%)<ref name="pmid18781943">{{cite journal | vauthors = Chen C | title = Physicochemical, pharmacological and pharmacokinetic properties of the zwitterionic antihistamines cetirizine and levocetirizine | journal = Current Medicinal Chemistry | volume = 15 | issue = 21 | pages = 2173–2191 | year = 2008 | pmid = 18781943 | doi = 10.2174/092986708785747625 }}</ref>

| C=21 | H=25 | Cl=1 | N=2 | O=3

| protein_bound = 88–96%<ref name="pmid18781943" />

| molecular_weight = 388.89

| metabolism = Minimal (non-[[cytochrome P450]]-mediated)<ref name="pmid14680442" /><ref name="pmid10384858" />

| smiles = Clc1ccc(cc1)C(c2ccccc2)N3CCN(CC3)CCOCC(=O)O

| metabolites =

| InChI = 1/C21H25ClN2O3/c22-19-8-6-18(7-9-19)21(17-4-2-1-3-5-17)24-12-10-23(11-13-24)14-15-27-16-20(25)26/h1-9,21H,10-16H2,(H,25,26)

| onset = 20–42 minutes<ref name="pmid10384858" />

| InChIKey = ZKLPARSLTMPFCP-UHFFFAOYAC

| elimination_half-life = Mean: 8.3 hours<ref name="pmid14680442" /><ref name="pmid10384858" /> Range: 6.5–10 hours<ref name="pmid12517581">{{cite journal | vauthors = Simons FE | title = Comparative pharmacology of H1 antihistamines: clinical relevance | journal = The American Journal of Medicine | volume = 113 | issue = Suppl 9A | pages = 38S–46S | date = December 2002 | pmid = 12517581 | doi = 10.1016/s0002-9343(02)01436-5 }}</ref>

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| duration_of_action = ≥24 hours<ref name="pmid12517581" />

| StdInChI = 1S/C21H25ClN2O3/c22-19-8-6-18(7-9-19)21(17-4-2-1-3-5-17)24-12-10-23(11-13-24)14-15-27-16-20(25)26/h1-9,21H,10-16H2,(H,25,26)

| excretion = [[Urine]]: 70–85%<ref name="pmid14680442" /> [[Feces]]: 10–13%<ref name="pmid14680442" />

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = ZKLPARSLTMPFCP-UHFFFAOYSA-N

| synonyms = Alatrol, Alzene, Cetirizina, Cetirin, Cetzine, Cetirizin, Cezin, Humex, Letizen, Razene, Reactine, Zyrtec, Zirtec, Zodac, Zirtek, Zynor, Zyrlek, Zyllergy

| CAS_number_Ref = {{cascite|correct|??}}

| CAS_number = 83881-51-0

| CAS_supplemental =

| PubChem = 2678

| IUPHAR_ligand = 1222

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| DrugBank = DB00341

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 2577

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = YO7261ME24

| KEGG_Ref = {{keggcite|correct|kegg}}

| KEGG = D07662

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 3561

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 1000

| NIAID_ChemDB =

| PDB_ligand =

| synonyms =

| IUPAC_name = (±)-[2-[4-[(4-Chlorophenyl)phenylmethyl]-1-piperazinyl]ethoxy]acetic acid

| C = 21

| H = 25

| Cl = 1

| N = 2

| O = 3

| SMILES = Clc1ccc(cc1)C(c2ccccc2)N3CCN(CC3)CCOCC(=O)O

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C21H25ClN2O3/c22-19-8-6-18(7-9-19)21(17-4-2-1-3-5-17)24-12-10-23(11-13-24)14-15-27-16-20(25)26/h1-9,21H,10-16H2,(H,25,26)

| StdInChI_comment =

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = ZKLPARSLTMPFCP-UHFFFAOYSA-N

| density =

| density_notes =

| melting_point =

| melting_high =

| melting_notes =

| boiling_point =

| boiling_notes =

| solubility =

| sol_units =

| specific_rotation =

}}

'''Cetirizine''' ({{IPAc-en|icon|s|ɛ|ˈ|t|ɪr|ɨ|z|iː|n}}), a second-generation [[antihistamine]], is a major [[metabolite]] of [[hydroxyzine]], and a [[racemic]] [[histamine H1 receptor|selective H1 receptor]] [[inverse agonist]] used in the treatment of [[allergies]], [[hay fever]], [[angioedema]], and [[urticaria]].

'''Cetirizine''' is a [[second-generation antihistamine]] used to treat [[allergic rhinitis]] (hay fever), [[dermatitis]], and [[urticaria]] (hives).<ref name="BNF76" /> It is taken by mouth.<ref name="AHFS2019" /> Effects generally begin within thirty minutes and last for about a day.<ref name="AHFS2019" /> The degree of benefit is similar to other antihistamines such as [[diphenhydramine]], which is a [[first-generation antihistamine]].<ref name="AHFS2019" />

==Availability==

Common side effects include sleepiness, dry mouth, headache, and abdominal pain.<ref name=AHFS2019/> The degree of sleepiness that occurs is generally less than with [[first-generation antihistamine]]s because second-generation antihistamines are more selective for the [[Histamine H1 receptor|H1 receptor]].<ref name=":3">{{cite journal | vauthors = Slater JW, Zechnich AD, Haxby DG | title = Second-generation antihistamines: a comparative review | journal = Drugs | volume = 57 | issue = 1 | pages = 31–47 | date = January 1999 | pmid = 9951950 | doi = 10.2165/00003495-199957010-00004 | s2cid = 46984477 }}</ref><ref name="BNF76" /> Compared to other second-generation anti-histamines, cetirizine can cause drowsiness.<ref name=":3" /> Among second-generation antihistamines, cetirizine is more likely than [[fexofenadine]] and [[loratadine]] to cause drowsiness.<ref name=PMID9951950/>

[[File:Cetirizine10.JPG|thumb|left|120px]]

Formerly prescription-only in the USA and Canada, cetirizine is now available [[Over-the-counter drug|over-the-counter]] in both countries as '''Zyrtec''' and '''Reactine''' respectively. Zyrtec was the highest-grossing new non-food product of 2008 in the US, generating sales of $315.9 million.<ref>{{cite news |first= Stuart|last= Elliott|coauthors= |title=A Strategy When Times Are Tough: "It's New!" |url= http://www.nytimes.com/2009/03/25/business/media/25adco.html |work= |page= |newspaper= [[The New York Times]]|date=24 March 2009 |accessdate=26 March 2009 |quote= }}</ref> It is also available as a [[generic drug]]. In Australia, Zyrtec is available over-the-counter in pharmacies and in the UK cetirizine can be sold in limited quantities off-the-shelf in any outlet and is often available in supermarkets. As of 2009, Germany made many generic drugs containing cetirizine available in pharmacies without prescription.<ref>{{cite web | title=Cetirizin | url=http://de.wikipedia.org/wiki/Cetirizin }}</ref> Norway, Sweden<ref>{{cite web | title=Cetirizin | url=http://receptfria.se/sandoz_camp/front/front/visa_underkategori?h_kategori_id=5&u_kategori_id=12 }}</ref> and Finland also recognize Cetirizine as an [[Over-the-counter drug|over-the-counter]] medicine. In India it is sold over-the-counter as brand-name 'Cetzine', even though it remains classified as a [[Schedule H]] (prescription) drug<ref>[http://www.drugscontrol.org/Schedule_H.pdf Drugs and Cosmetics (2nd amendment) rules, 2006]. item 104 in schedule H.</ref>

Use in [[pregnancy]] appears safe, but use during [[breastfeeding]] is not recommended.<ref name="Preg2019">{{cite web |title=Cetirizine Pregnancy and Breastfeeding Warnings |url=https://www.drugs.com/pregnancy/cetirizine.html |website=Drugs.com |access-date=3 March 2019 |language=en |archive-date=6 March 2019 |archive-url=https://web.archive.org/web/20190306044632/https://www.drugs.com/pregnancy/cetirizine.html |url-status=live }}</ref> The medication works by blocking [[histamine]] H1 receptors, mostly outside the [[brain]].<ref name="AHFS2019">{{cite web |title=Cetirizine Hydrochloride Monograph for Professionals |url=https://www.drugs.com/monograph/cetirizine-hydrochloride.html |website=Drugs.com |publisher=American Society of Health-System Pharmacists |access-date=3 March 2019 |archive-date=28 August 2021 |archive-url=https://web.archive.org/web/20210828025357/https://www.drugs.com/monograph/cetirizine.html |url-status=live }}</ref>

Cetirizine can be used for paediatric patients. The main side effect to be cautious about is [[somnolence]].<ref>{{cite journal | vauthors = Zhou P, Jia Q, Wang Z, Zhao R, Zhou W | title = Cetirizine for the treatment of allergic diseases in children: A systematic review and meta-analysis | journal = Frontiers in Pediatrics | volume = 10 | pages = 940213 | date = 25 August 2022 | pmid = 36090559 | pmc = 9452751 | doi = 10.3389/fped.2022.940213 | doi-access = free }}</ref>

It was patented in 1983<ref name=":0" /><ref>{{Cite patent|number=US4525358A|title=2-[4-(Diphenylmethyl)-1-piperazinyl]-acetic acids and their amides|gdate=1985-06-25|invent1=Baltes|invent2=Lannoy|invent3=Rodriguez|inventor1-first=Eugene|inventor2-first=Jean de|inventor3-first=Ludovic|url=https://patents.google.com/patent/US4525358A/en}}</ref> and came into medical use in 1987.<ref name=Fis2006>{{cite book | vauthors = Fischer J, Ganellin CR |title=Analogue-based Drug Discovery |date=2006 |publisher=John Wiley & Sons |isbn=9783527607495 |page=549 |url=https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA549 |language=en |access-date=19 September 2020 |archive-date=8 October 2022 |archive-url=https://web.archive.org/web/20221008080257/https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA549 |url-status=live }}</ref> It is on the [[WHO Model List of Essential Medicines|World Health Organization's List of Essential Medicines]].<ref name="WHO23rd">{{cite book | vauthors = ((World Health Organization)) | title = The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023) | year = 2023 | hdl = 10665/371090 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MHP/HPS/EML/2023.02 | hdl-access=free }}</ref> It is available as a [[generic medication]].<ref name=BNF76>{{cite book|title=British national formulary : BNF 76|date=2018|publisher=Pharmaceutical Press|isbn=9780857113382|pages=279|edition=76}}</ref> In 2022, it was the 43rd most commonly prescribed medication in the United States, with more than 13{{nbsp}}million prescriptions.<ref>{{cite web | title=The Top 300 of 2022 | url=https://clincalc.com/DrugStats/Top300Drugs.aspx | website=ClinCalc | access-date=30 August 2024 | archive-date=30 August 2024 | archive-url=https://web.archive.org/web/20240830202410/https://clincalc.com/DrugStats/Top300Drugs.aspx | url-status=live }}</ref><ref>{{cite web | title = Cetirizine Drug Usage Statistics, United States, 2013 - 2022 | website = ClinCalc | url = https://clincalc.com/DrugStats/Drugs/Cetirizine | access-date = 30 August 2024 }}</ref>

== Medical uses ==

=== Allergies ===

Cetirizine's primary indication is for [[hay fever]] and other allergies. Because the symptoms of itching and redness in these conditions are caused by histamine acting on the H1 receptor, blocking those receptors temporarily relieves those symptoms.<ref name=":1">{{cite book| vauthors = Rang HP, Dale MM, Flower RJ, Henderson G |url=https://www.worldcat.org/oclc/903083639|title=Rang and Dale's pharmacology|date=21 January 2015 |isbn=978-0-7020-5362-7|edition=Eighth|location=[United Kingdom]|pages=332|oclc=903083639}}</ref>

Cetirizine is also commonly prescribed to treat acute and (in particular cases) chronic urticaria (hives), more efficiently than any other second-generation antihistamine.<ref name=":1" />

=== Available forms ===

Cetirizine is available over-the-counter in the US in the form of 5 and 10 mg [[tablet (pharmacy)|tablets]]. A 20 mg strength is available by prescription only.<ref name="pmid14680442" /> It is also available as a 1 mg/mL syrup for oral administration by prescription. In the UK, up to 30 tablets of 10 mg are on the general sales list (of pharmaceuticals) and can be purchased without a prescription and without pharmacist supervision.<ref name=":2">{{Cite web|title=CETIRIZINE HYDROCHLORIDE|url=https://bnf.nice.org.uk/drug/cetirizine-hydrochloride.html|access-date=17 October 2020|archive-date=10 October 2022|archive-url=https://web.archive.org/web/20221010052416/https://www.nice.org.uk/bnf-uk-only|url-status=live}}</ref> The drug can be in the form of tablets, capsules or a syrup.<ref name=":2" />

== Adverse effects ==

Commonly reported side effects of cetirizine include [[headache]], [[dry mouth]], [[drowsiness]], and [[fatigue (medical)|fatigue]], while more serious, but rare, adverse effects reported include [[tachycardia]] and [[edema]].<ref>{{cite web|title=Zyrtec Side Effects|url=https://www.drugs.com/sfx/zyrtec-side-effects.html|website=drugs.com|access-date=21 August 2015|archive-date=23 July 2019|archive-url=https://web.archive.org/web/20190723081747/https://www.drugs.com/sfx/zyrtec-side-effects.html|url-status=live}}</ref>

=== Pruritus after discontinuation of cetirizine ===

Discontinuing cetirizine after prolonged use (typically, use beyond six months) may result in pruritus (generalized [[itchiness]]).<ref>{{cite journal | vauthors = Ekhart C, van der Horst P, van Hunsel F | title = Unbearable Pruritus After Withdrawal of (Levo)cetirizine | journal = Drug Safety: Case Reports | volume = 3 | issue = 1 | pages = 16 | date = December 2016 | pmid = 27889900 | pmc = 5124431 | doi = 10.1007/s40800-016-0041-9 }}</ref><ref>{{cite web |title=Cetirizine (Zyrtec) Withdrawal & Unbearable Itching |url= https://www.peoplespharmacy.com/2013/05/06/cetirizine-zyrtec-withdrawal-unbearable-itching/|archive-url=https://web.archive.org/web/20130814045348/http://www.peoplespharmacy.com/2013/05/06/cetirizine-zyrtec-withdrawal-unbearable-itching/|url-status=dead|archive-date=14 August 2013|website=People's Pharmacy|access-date=9 September 2017}}</ref><ref>{{cite web|title=addicted to zyrtec?|url=http://www.medhelp.org/posts/Allergy/addicted-to-zyrtec/show/600862|website=MedHelp|access-date=9 September 2017|archive-date=16 September 2017|archive-url=https://web.archive.org/web/20170916010832/http://www.medhelp.org/posts/Allergy/addicted-to-zyrtec/show/600862|url-status=live}}</ref>

The United States Food and Drug Administration (FDA) analyzed cases of pruritus after stopping cetirizine in the FDA Adverse Event Reporting System (FAERS) database and medical literature through 24 April 2017. Their report noted that some patients indicated the itchiness impacted their ability to work, sleep or perform normal daily activities.<ref>{{cite journal | vauthors = Chung AH, La Grenade L, Harinstein LM | title = Pruritus after discontinuation of cetirizine | journal = Therapeutic Advances in Drug Safety | volume = 10 | pages = 2042098619859996 | date = 2019 | pmid = 31308927 | pmc = 6613055 | doi = 10.1177/2042098619859996 }}</ref>

No specific schedule for weaning is currently provided in the drug information for cetirizine.<ref>{{Cite web | vauthors = Borst H |date=18 May 2023 |title=Did you know stopping Zyrtec can cause withdrawal? |url=https://www.singlecare.com/blog/zyrtec-withdrawal/ |access-date=23 July 2023 |website=The Checkup |language=en-US}}</ref>

== Pharmacology ==

[[File:Cetirizine structure racemic.svg|thumb|200px|right|L-Stereoisomer, [[levocetirizine]] (top) and D-stereoisomer of cetirizine.]]

Cetirizine crosses the [[blood-brain barrier]] only slightly, reducing the sedative side-effect common with older antihistamines. <ref name="blood-brain">{{cite journal| doi = 10.1124/dmd.105.007211| title = Brain distribution of cetirizine enantiomers: comparison of three different tissue-to-plasma partition coefficients: K(p), K(p,u), and K(p,uu)| last = Gupta| first = A| coauthors = Chatelain P, Massingham R, Jonsson EN, Hammarlund-Udenaes M| journal = Drug Metab. Dispos.| volume = 34| issue = 2| pages = 318–23| year = 2006| month = February| pmid = 16303872| url = dmd.aspetjournals.org/content/34/2/318.long}}</ref> It has also been shown to inhibit [[eosinophil]] [[chemotaxis]] and [[LTB4]] release. At a dosage of 20 mg, Boone ''et al.'' found that it inhibited the expression of [[VCAM-1]] in patients with [[atopic dermatitis]].<ref>{{cite journal| author = Boone M, Lespagnard L, Renard N, Song M, Rihoux JP| title = Adhesion molecule profiles in atopic dermatitis vs. allergic contact dermatitis: pharmacological modulation by cetirizine| journal = J Eur Acad Dermatol Venereol| volume = 14| issue = 4| pages = 263–6| year = 2000| month = July|doi = 10.1046/j.1468-3083.2000.00017.x

|url=http://www3.interscience.wiley.com/journal/119045164/abstract?CRETRY=1&SRETRY=0| accessdate = 2009-11-19| pmid = 11204513}}</ref>

=== Pharmacodynamics ===

The [[levorotary]] [[enantiomer]] of cetirizine, known as [[levocetirizine]], is the more active form.

Cetirizine acts as a highly [[binding selectivity|selective]] [[receptor antagonist|antagonist]] of the histamine H1 receptor.<ref name="pmid14680442">{{cite journal | vauthors = Portnoy JM, Dinakar C | title = Review of cetirizine hydrochloride for the treatment of allergic disorders | journal = Expert Opinion on Pharmacotherapy | volume = 5 | issue = 1 | pages = 125–135 | date = January 2004 | pmid = 14680442 | doi = 10.1517/14656566.5.1.125 | s2cid = 28946859 }}</ref> The [[Ligand (biochemistry)#Receptor/ligand binding affinity|Ki values]] for the H1 receptor are approximately 6 nM for cetirizine, 3 nM for [[levocetirizine]], and 100 nM for [[dextrocetirizine]], indicating that the [[levorotatory]] [[enantiomer]] is the main active form.<ref name="pmid14680442" /> Cetirizine has 600-fold or greater [[binding selectivity|selectivity]] for the H1 receptor over a wide variety of other sites, including [[muscarinic acetylcholine receptor|muscarinic acetylcholine]], [[serotonin receptor|serotonin]], [[dopamine receptor|dopamine]], and [[α-adrenergic receptor]]s, among many others.<ref name="pmid14680442" /> The drug shows 20,000-fold or greater selectivity for the H1 receptor over the five muscarinic acetylcholine receptors, and hence does not exhibit [[anticholinergic]] effects.<ref name="pmid23867423">{{cite journal | vauthors = Zhang L, Cheng L, Hong J | title = The clinical use of cetirizine in the treatment of allergic rhinitis | journal = Pharmacology | volume = 92 | issue = 1–2 | pages = 14–25 | year = 2013 | pmid = 23867423 | doi = 10.1159/000351843 | title-link = doi | doi-access = free }}</ref><ref name="pmid15627436">{{cite journal | vauthors = Orzechowski RF, Currie DS, Valancius CA | title = Comparative anticholinergic activities of 10 histamine H1 receptor antagonists in two functional models | journal = European Journal of Pharmacology | volume = 506 | issue = 3 | pages = 257–264 | date = January 2005 | pmid = 15627436 | doi = 10.1016/j.ejphar.2004.11.006 }}</ref> It shows negligible inhibition of the [[hERG]] channel ({{abbrlink|IC50|half-maximal inhibitory concentration}} > 30 μM)<ref name="pmid9658196">{{cite journal | vauthors = Taglialatela M, Pannaccione A, Castaldo P, Giorgio G, Zhou Z, January CT, Genovese A, Marone G, Annunziato L | title = Molecular basis for the lack of HERG K+ channel block-related cardiotoxicity by the H1 receptor blocker cetirizine compared with other second-generation antihistamines | journal = Molecular Pharmacology | volume = 54 | issue = 1 | pages = 113–121 | date = July 1998 | pmid = 9658196 | doi = 10.1124/mol.54.1.113 }}</ref> and no [[cardiotoxicity]] has been observed with cetirizine at doses of up to 60 mg/day, six times the normal recommended dose<ref name="pmid14680442" /> and the highest dose of cetirizine that has been studied in healthy subjects.<ref name="pmid17891537">{{cite journal | vauthors = Hulhoven R, Rosillon D, Letiexhe M, Meeus MA, Daoust A, Stockis A | title = Levocetirizine does not prolong the QT/QTc interval in healthy subjects: results from a thorough QT study | journal = European Journal of Clinical Pharmacology | volume = 63 | issue = 11 | pages = 1011–1017 | date = November 2007 | pmid = 17891537 | doi = 10.1007/s00228-007-0366-5 | quote = The equivalent dose of 60 mg cetirizine is also the highest dose ever administered in healthy subjects [13]. | s2cid = 36218027 }}</ref>

Cetirizine crosses the [[blood–brain barrier]] only slightly, and for this reason, produces minimal sedation compared to many other antihistamines.<ref name="blood-brain">{{cite journal | vauthors = Gupta A, Chatelain P, Massingham R, Jonsson EN, Hammarlund-Udenaes M | title = Brain distribution of cetirizine enantiomers: comparison of three different tissue-to-plasma partition coefficients: K(p), K(p,u), and K(p,uu) | journal = Drug Metabolism and Disposition | volume = 34 | issue = 2 | pages = 318–323 | date = February 2006 | pmid = 16303872 | doi = 10.1124/dmd.105.007211 | s2cid = 9111905 }}</ref> A [[positron emission tomography]] (PET) study found that brain occupancy of the H1 receptor was 12.6% for 10 mg cetirizine, 25.2% for 20 mg cetirizine, and 67.6% for 30 mg [[hydroxyzine]].<ref name="pmid19697300">{{cite journal | vauthors = Tashiro M, Kato M, Miyake M, Watanuki S, Funaki Y, Ishikawa Y, Iwata R, Yanai K | title = Dose dependency of brain histamine H(1) receptor occupancy following oral administration of cetirizine hydrochloride measured using PET with [11C]doxepin | journal = Human Psychopharmacology | volume = 24 | issue = 7 | pages = 540–548 | date = October 2009 | pmid = 19697300 | doi = 10.1002/hup.1051 | s2cid = 5596000 }}</ref> (A 10 mg dose of cetirizine equals about a 30 mg dose of hydroxyzine in terms of peripheral antihistamine effect.)<ref name="pmid28289538">{{cite journal | vauthors = van den Elzen MT, van Os-Medendorp H, van den Brink I, van den Hurk K, Kouznetsova OI, Lokin AS, Laheij-de Boer AM, Röckmann H, Bruijnzeel-Koomen CA, Knulst AC | title = Effectiveness and safety of antihistamines up to fourfold or higher in treatment of chronic spontaneous urticaria | journal = Clinical and Translational Allergy | volume = 7 | pages = 4 | year = 2017 | pmid = 28289538 | pmc = 5309999 | doi = 10.1186/s13601-017-0141-3 | quote = [...] 30 mg of hydroxyzine equals about 10 mg cetirizine [11] [...] | doi-access = free }}</ref> PET studies with antihistamines have found that brain H1 receptor occupancy of more than 50% is associated with a high prevalence of somnolence and cognitive decline, whereas brain H1 receptor occupancy of less than 20% is considered to be non-[[sedative]].<ref name="pmid16890992">{{cite journal | vauthors = Yanai K, Tashiro M | title = The physiological and pathophysiological roles of neuronal histamine: an insight from human positron emission tomography studies | journal = Pharmacology & Therapeutics | volume = 113 | issue = 1 | pages = 1–15 | date = January 2007 | pmid = 16890992 | doi = 10.1016/j.pharmthera.2006.06.008 }}</ref> In accordance, H1 receptor occupancy correlated well with subjective sleepiness for 30 mg hydroxyzine but there was no correlation for 10 or 20 mg cetirizine.<ref name="pmid19697300" /> As such, brain penetration and brain H1 receptor occupancy by cetirizine are dose-dependent, and in accordance, while cetirizine at doses of 5 to 10 mg have been reported to be non-sedating or mildly sedating, a higher dose of 20 mg has been found to induce significant drowsiness in other studies.<ref name="pmid19697300" />

[[File:Cetirizine structure racemic.svg|thumb|180px|left|L-Stereosimer, [[levocetirizine]] (top) and D-stereoisomer of cetirizine]]{{clear-left}}

Cetirizine also shows anti-inflammatory properties independent of H1 receptors.<ref name="pmid8645978">{{cite journal | vauthors = Köller M, Hilger RA, Rihoux JP, König W | title = Cetirizine exerts anti-inflammatory effects on human neutrophils | journal = International Archives of Allergy and Immunology | volume = 110 | issue = 1 | pages = 52–56 | date = May 1996 | pmid = 8645978 | doi = 10.1159/000237310 }}</ref> The effect is exhibited through suppression of the [[NF-κB]] pathway, and by regulating the release of [[cytokine]]s and [[chemokine]]s, thereby regulating the recruitment of inflammatory cells.<ref name="pmid15631542">{{cite journal | vauthors = Bielory L, Lien KW, Bigelsen S | title = Efficacy and tolerability of newer antihistamines in the treatment of allergic conjunctivitis | journal = Drugs | volume = 65 | issue = 2 | pages = 215–228 | date = 2005 | pmid = 15631542 | doi = 10.2165/00003495-200565020-00004 | s2cid = 46791611 }}</ref><ref name="pmid8156449">{{cite journal | vauthors = Walsh GM | title = The anti-inflammatory effects of cetirizine | journal = Clinical and Experimental Allergy | volume = 24 | issue = 1 | pages = 81–85 | date = January 1994 | pmid = 8156449 | doi = 10.1111/j.1365-2222.1994.tb00921.x | s2cid = 32269456 }}</ref><ref name="pmid14741075">{{cite journal | vauthors = Gelfand EW, Appajosyula S, Meeves S | title = Anti-inflammatory activity of H1-receptor antagonists: review of recent experimental research | journal = Current Medical Research and Opinion | volume = 20 | issue = 1 | pages = 73–81 | date = January 2004 | pmid = 14741075 | doi = 10.1185/030079903125002586 | s2cid = 20451677 }}</ref><ref name="pmid15245363">{{cite journal | vauthors = Fumagalli F, Baiardini I, Pasquali M, Compalati E, Guerra L, Massacane P, Canonica GW | title = Antihistamines: do they work? Further well-controlled trials involving larger samples are needed | journal = Allergy | volume = 59 | issue = Suppl 78 | pages = 74–77 | date = August 2004 | pmid = 15245363 | doi = 10.1111/j.1398-9995.2004.00573.x | s2cid = 39936983 }}</ref><ref name="pmid9602225">{{cite journal | vauthors = Grob JJ, Castelain M, Richard MA, Bonniol JP, Béraud V, Adhoute H, Guillou N, Bonerandi JJ | title = Antiinflammatory properties of cetirizine in a human contact dermatitis model. Clinical evaluation of patch tests is not hampered by antihistamines | journal = Acta Dermato-Venereologica | volume = 78 | issue = 3 | pages = 194–197 | date = May 1998 | pmid = 9602225 | doi = 10.1080/000155598441512 | title-link = doi | doi-access = free }}</ref> It has been shown to inhibit [[eosinophil]] [[chemotaxis]] and [[LTB4]] release.<ref name="pmid11204513">{{cite journal | vauthors = Boone M, Lespagnard L, Renard N, Song M, Rihoux JP | title = Adhesion molecule profiles in atopic dermatitis vs. allergic contact dermatitis: pharmacological modulation by cetirizine | journal = Journal of the European Academy of Dermatology and Venereology | volume = 14 | issue = 4 | pages = 263–266 | date = July 2000 | pmid = 11204513 | doi = 10.1046/j.1468-3083.2000.00017.x | s2cid = 24026684 }}</ref> At a dosage of 20 mg, Boone ''et al.'' found that it inhibited the expression of [[VCAM-1]] in patients with [[atopic dermatitis]].<ref name="pmid11204513" />

== Administration method and metabolism ==

=== Pharmacokinetics ===

Chewable, non-chewable, and syrup forms of cetirizine are similarly absorbed rapidly and effectively, with absorbed food minutely affecting the absorption rate which yields a peak serum level one hour after administration;<ref name="drugref_cetirizine">{{cite book| author = Anderson, Philip; Knoben, James E.; Troutman, William G.| title = Handbook of clinical drug data| publisher = McGraw-Hill| location = New York| year = 2002| page = 807| isbn = 0-07-136362-9

| accessdate = 2009-11-19}}</ref> in a study of healthy volunteers prescribed 10 mg tablets, once daily for 10 days, a mean peak serum level of 311 ng/mL was observed.<ref name="pfizer_ceti_p3">{{cite web| url = http://www.pfizer.com/files/products/uspi_zyrtec.pdf| title = Zyrtec prescribing information| date = May 2006 | accessdate = 2009-11-19}}</ref> The metabolic effects of cetirizine are long acting, remaining in the system for a maximum of 21 hours before being excreted; the average elimination half-life is 8 hours. About 70% of the drug is removed through urination, of which half is observed as unchanged cetirizine compound. Another 10% is excreted.<ref name="drugref_cetirizine"/><ref name="pfizer_ceti_p3"/>

==== Absorption ====

Like many other antihistamine medications, cetirizine is commonly prescribed in combination with [[pseudoephedrine hydrochloride]], a [[decongestant]]. These combinations are marketed using the same brand name as the cetirizine with a "-D" suffix ('''Zyrtec-D''', '''Virlix-D''', etc.)

Cetirizine is rapidly and extensively [[absorption (pharmacokinetics)|absorbed]] upon [[oral administration]] in tablet or syrup form.<ref name="pmid14680442" /> The [[oral administration|oral]] [[bioavailability]] of cetirizine is at least 70% and of levocetirizine is at least 85%.<ref name="pmid18781943" /> The [[Tmax (pharmacology)|Tmax]] of cetirizine is approximately 1.0 hour regardless of formulation.<ref name="pmid10384858" /> The [[pharmacokinetics]] of cetirizine have been found to increase linearly with dose across a range of 5 to 60 mg.<ref name="pmid14680442" /> Its [[Cmax (pharmacology)|Cmax]] following a single dose has been found to be 257 ng/mL for 10 mg and 580 ng/mL for 20 mg.<ref name="pmid10384858">{{cite journal | vauthors = Simons FE, Simons KJ | title = Clinical pharmacology of new histamine H1 receptor antagonists | journal = Clinical Pharmacokinetics | volume = 36 | issue = 5 | pages = 329–352 | date = May 1999 | pmid = 10384858 | doi = 10.2165/00003088-199936050-00003 | s2cid = 21360079 }}</ref> Food has no effect on the bioavailability of cetirizine but has been found to delay the Tmax by 1.7 hours (i.e., to approximately 2.7 hours) and to decrease the Cmax by 23%.<ref name="pmid14680442" /><ref name="pmid10384858" /><ref name="pmid28622592">{{cite journal | vauthors = Paśko P, Rodacki T, Domagała-Rodacka R, Palimonka K, Marcinkowska M, Owczarek D | title = Second generation H1 - antihistamines interaction with food and alcohol-A systematic review | journal = Biomedicine & Pharmacotherapy | volume = 93 | pages = 27–39 | date = September 2017 | pmid = 28622592 | doi = 10.1016/j.biopha.2017.06.008 }}</ref> Similar findings were reported for levocetirizine, which had its Tmax delayed by 1.25 hours and its Cmax decreased by about 36% when administered with a high-fat meal.<ref name="pmid28622592" /> [[Steady-state (pharmacokinetics)|Steady-state levels]] of cetirizine occur within 3 days and there is no accumulation of the drug with chronic administration.<ref name="pmid10384858" /> Following once-daily administration of 10 mg cetirizine for ten days, the mean Cmax was 311 ng/mL.<ref name="pfizer_ceti_p3">{{cite web|url=http://www.pfizer.com/files/products/uspi_zyrtec.pdf |title=Zyrtec prescribing information |date=May 2006 |access-date=19 November 2009 |url-status=dead |archive-url=https://web.archive.org/web/20100104143424/http://www.pfizer.com/files/products/uspi_zyrtec.pdf |archive-date=4 January 2010 }}</ref>

==== Distribution ====

Formerly only available by a prescription, both Zyrtec and Zyrtec-D in November 2007 became available over-the-counter in the United States.<ref>

The mean [[plasma protein binding]] of cetirizine has been found to be 93 to 96% across a range of 25 to 1,000 ng/mL independent of concentration.<ref name="pmid10384858" /> Plasma protein binding of 88 to 96% has also been reported across multiple studies.<ref name="pmid18781943" /> The drug is bound to [[human serum albumin|albumin]] with high [[affinity (pharmacology)|affinity]], while [[orosomucoid|α1-acid glycoprotein]] and [[lipoprotein]]s contribute much less to total plasma protein binding.<ref name="pmid18781943" /> The unbound or free fraction of levocetirizine has been reported to be 8%.<ref name="pmid18781943" /> The true [[volume of distribution]] of cetirizine is unknown but is estimated to be 0.3 to 0.45 L/kg.<ref name="pmid14680442" /><ref name="pmid18781943" /> Cetirizine poorly and slowly crosses the [[blood–brain barrier]], which is thought to be due to its chemical properties and its activity as a [[P-glycoprotein]] [[substrate (biochemistry)|substrate]].<ref name="pmid26291661">{{cite journal | vauthors = Hu Y, Sieck DE, Hsu WH | title = Why are second-generation H1-antihistamines minimally sedating? | journal = European Journal of Pharmacology | volume = 765 | issue = | pages = 100–106 | date = October 2015 | pmid = 26291661 | doi = 10.1016/j.ejphar.2015.08.016 }}</ref><ref name="pmid18781943" /><ref name="pmid23564211">{{cite journal | vauthors = Conen S, Theunissen EL, Vermeeren A, van Ruitenbeek P, Stiers P, Mehta MA, Toennes SW, Ramaekers JG | title = The role of P-glycoprotein in CNS antihistamine effects | journal = Psychopharmacology | volume = 229 | issue = 1 | pages = 9–19 | date = September 2013 | pmid = 23564211 | doi = 10.1007/s00213-013-3075-z | s2cid = 10416220 }}</ref>

{{cite journal| title = Over-the-Counter Zyrtec: a Money-Saver?| first = January W| last = Payne| journal = [[U.S. News & World Report]]| date = 2008-01-09|url = http://health.usnews.com/articles/health/2008/01/09/over-the-counter-zyrtec-is-about-to-arrive.html}}</ref>

== ~~Indications~~ ==

==== Metabolism ====

Cetirizine is notably not metabolized by the [[cytochrome P450]] system.<ref name="Mahmoudi2016">{{cite book| vauthors = Mahmoudi M |title=Allergy and Asthma: Practical Diagnosis and Management|url=https://books.google.com/books?id=spdPDAAAQBAJ&pg=PA574|date=2 June 2016|publisher=Springer|isbn=978-3-319-30835-7|pages=574–}}</ref> Because of this, it does not interact significantly with drugs that [[enzyme inhibitor|inhibit]] or [[enzyme inducer|induce]] cytochrome P450 enzymes such as [[theophylline]], [[erythromycin]], [[clarithromycin]], [[cimetidine]], or [[alcohol (drug)|alcohol]].<ref name="pmid14680442" /> Studies with cetirizine synthesized with radioactive carbon-14 show that 90% of excreted cetirizine is unchanged at 2 hours, 80% at 10 hours, and 70% at 24 hours, indicating limited and slow metabolism.<ref name="pmid10384858" /> While cetirizine does not undergo extensive metabolism or metabolism by the cytochrome P450 enzyme, it does undergo some metabolism by other means, the [[metabolic pathway]]s of which include [[oxidation]] and [[conjugation (biochemistry)|conjugation]].<ref name="pmid14680442" /><ref name="pmid10384858" /> The precise enzymes responsible for [[biotransformation|transformation]] of cetirizine have not been identified.<ref name="pmid14680442" />

=== Allergies ===

Cetirizine's primary indication is for hay fever and other allergies. Because the symptoms of itching and redness in these conditions are caused by histamine acting on the H1 receptor, blocking those receptors temporarily relieves those symptoms.

=== ~~Rhinovirus infection~~ ===

==== Elimination ====

Cetirizine is [[elimination (pharmacology)|eliminated]] approximately 70 to 85% in the [[urine]] and 10 to 13% in the [[feces]].<ref name="pmid14680442" /> In total, about 60% of cetirizine eliminated in the urine is unchanged.<ref name="pmid14680442" /><ref name="pmid10384858" /> It is eliminated in the urine via an [[active transport]] mechanism.<ref name="pmid10384858" /> The [[elimination half-life]] of cetirizine ranges from 6.5 to 10 hours in healthy adults, with a mean across studies of approximately 8.3 hours.<ref name="pmid14680442" /><ref name="pmid10384858" /> The elimination half-life of cetirizine is increased in the elderly (to 12 hours), in [[hepatic impairment]] (to 14 hours), and in [[renal impairment]] (to 20 hours).<ref name="pmid10384858" /> Concentrations of cetirizine in the skin decline much slower than concentrations in the blood plasma.<ref name="pmid10384858" /> Its [[duration of action]] is at least 24 hours.<ref name="pmid10384858" />

== Chemistry ==

[[Interleukin 6]] and [[interleukin 8]] have been shown to be elevated in acute respiratory distress syndrome.<ref name="pmid8406851">{{cite journal| last1=Chollet-Martin| first1=S| last2=Montravers| first2=P| last3=Gibert| first3=C| last4=Elbim| first4=C| last5=Desmonts| first5=JM| last6=Fagon| first6=JY| last7=Gougerot-Pocidalo| first7=MA| title=High levels of interleukin-8 in the blood and alveolar spaces of patients with pneumonia and adult respiratory distress syndrome.| journal=Infection and immunity| volume=61| issue=11| pages=4553–9| year=1993| pmid=8406851| pmc=281204}}</ref> Cetirizine contains L- and D-[[stereoisomer]]s. Chemically, [[levocetirizine]] is the active L-[[enantiomer]] of cetirizine. In a recent study of airway epithelial cells the following was observed: Levocetirizine inhibits the production of intercellular adhesion molecule [[ICAM-1]] and secretion of interleukin (IL)-6 and IL-8, which may have beneficial effects on the pathophysiologic changes related to human rhinovirus ([[rhinovirus|HRV]]) infection. Levocetirizine treatment inhibited the HRV-induced increase in ICAM-1 mRNA and protein levels, as well as the HRV-induced expression of IL-6 and IL-8 mRNA and protein levels. Viral titer, as measured by culture in MRC-5 cells, was reduced by levocetirizine. Levocetirizine treatment also reduced the increased nuclear factor-kappa B ([[NF-κB]]) expression seen with HRV infection. Levocetirizine inhibited the expression of Toll-like receptor 3 ([[TLR 3|TLR3]]) mRNA and protein levels. These findings indicate that, in HNEC and [[A549 cell|A549]] cells, levocetirizine inhibits HRV replication and HRV-induced upregulation of ICAM-1, IL-6, and IL-8, TLR3 expression and NF-κB activation. The results of this study suggest that levocetirizine may have a possible clinical application in the treatment of airway inflammation caused by HRV infection.<ref name="pmid19110001">{{cite journal| author = Jang YJ, Wang JH, Kim JS, Kwon HJ, Yeo NK, Lee BJ| title = Levocetirizine inhibits rhinovirus-induced ICAM-1 and cytokine expression and viral replication in airway epithelial cells

Cetirizine contains L- and D-[[stereoisomer]]s. Chemically, levocetirizine is the active L-[[enantiomer]] of cetirizine. The drug is a member of the [[diphenylmethylpiperazine]] group of antihistamines. [[Structural analog|Analogues]] include [[cyclizine]] and hydroxyzine.<ref>{{Cite web | work = PubChem |title=Cetirizine |url= https://pubchem.ncbi.nlm.nih.gov/compound/2678 |access-date=4 April 2022 | publisher = U.S. Naionatl Library of Medicine }}</ref>

| journal = Antiviral Res.| volume = 81| issue = 3| pages = 226–33| year = 2009| month = March| pmid = 19110001| doi = 10.1016/j.antiviral.2008.12.001| accessdate = 2009-11-19}}</ref> Airway inflammation caused from a [[cytokine storm]] secondary to acute respiratory distress syndrome could also theoretically benefit.

=== ~~Kimura's disease~~ ===

=== Synthesis ===

:[[File:Cetirizine synthesis.png|700px|thumb|center|Cetirizine synthesis:<ref name=":0">{{cite patent | country = US | number = 4525358 | status = patent | title = 2-[4-(Diphenylmethyl)-1-piperazinyl]-acetic acids and their amides | gdate = 25 June 1985 | fdate = 17 May 1983 | pridate = YYYY-MM-DD | inventor = Baltes E, De Lannoy J, Rodriguez L | assign1 = UCB Pharmaceuticals, Inc. }}</ref>]]

Cetirizine is an effective agent in treating the symptoms of [[Kimura's disease]], which mostly occurs in young Asian men, affecting the lymph nodes and soft tissue of the head and neck in the form of tumor-like lesions. Cetirizine's properties of being effective both in the treatment of [[pruritus]] (itching) and as an anti-inflammatory agent make it suitable for the treatment of the pruritus associated with these lesions.<ref name="kimura">{{cite journal|author = Ben-Chetrit E, Amir G, Shalit M| title = Cetirizine: An effective agent in Kimura's disease| journal = Arthritis Rheum.| volume = 53| issue = 1|pages = 117–8| year = 2005| month = February|doi = 10.1002/art.20908| accessdate = 2009-11-19| pmid = 15696573}}</ref> In a 2005 study, the American College of Rheumatology conducted treatments initially using [[prednisone]], followed by steroid dosages and [[azathioprine]], [[omeprazole]], and [[calcium]] and [[vitamin D]] supplements over the course of two years.<ref name="kimura" /> The skin condition of the patient began to improve and the skin lesions lessened. However, there were symptoms of [[cushing syndrome|cushingoid]] and [[hirsutism]] observed before the patient was removed from the courses of steroids and placed on 10 mg/day of cetirizine to prevent skin lesions;<ref name="kimura" /> an agent suitable for the treatment of pruritus associated with such lesions.<ref name="kimura" /> Asymptomatically, the patient's skin lesions disappeared after treatment with cetirizine, blood [[eosinophil]] counts became normal,<ref name="kimura" /> corticosteroid effects were resolved,<ref name="kimura" /> and a remission began within a period of two months.<ref name="kimura" /> It is also thought that the inhibition of eosinophils may be the key to treatment of Kimura's disease due to the role of eosinophils, rather than other cells with regards to the lesions of the skin.<ref name="kimura"/>

The 1-(4-chlorophenylmethyl)-piperazine is alkylated with methyl (2-chloroethoxy)-acetate in the presence of sodium carbonate and xylene solvent to produce the Sn2 substitution product in 28% yield. Saponification of the acetate ester is done by refluxing with potassium hydroxide in absolute ethanol to afford a 56% yield of the potassium salt intermediate. This is then hydrolyzed with aqueous HCl and extracted to give an 81% yield of the carboxylic acid product.<ref>{{Cite journal | vauthors = Reiter J, Trinka P, Bartha FL, Pongó L, Volk B, Simig G |date=20 July 2012 |title=New Manufacturing Procedure of Cetirizine |journal=Organic Process Research & Development |language=en |volume=16 |issue=7 |pages=1279–1282 |doi=10.1021/op300009y |issn=1083-6160}}</ref>

==Side Effects==

Dryness of the mouth, nose and throat, urinary retention, blurred vision and stomach ache are commonly reported side effects of this drug.<ref>{{cite book | title=British National Formulary (BNF) 61 | year=2011}}</ref>

==~~Synthesis~~==

== Availability ==

{{Multiple image

The following synthesis of this compound was reported in 1985:<ref>Baltes, E.; De Lannoy, J.; Rodriguez, L.; 1985, {{US Patent|4,525,358}}.</ref>

| direction = horizontal

| total_width = 425

| caption_align =

| header =

| footer =

| image1 = Cetirizine10.JPG

| width1 = 320

| height1 = 213

| alt1 =

| caption1 = A package of 10 mg cetirizine tablets.

| image2 = Zyrtec-D blister pack.png

| width2 = 296

| height2 = 240

| alt2 =

| caption2 = Zyrtec-D, a combination of cetirizine and pseudoephedrine.

}}

Cetirizine is available without a prescription.<ref>{{cite web | title = Cetirizine: Clinical Review | publisher = U.S. Food and Drug Administration | url = https://www.fda.gov/media/105988/download | date = 11 September 2016 }}</ref> In some countries, it is only available over-the-counter in packages containing seven or ten 10 mg doses.<ref>{{cite journal | vauthors = Aaronson DW | title = Evaluation of cetirizine in patients with allergic rhinitis and perennial asthma | journal = Annals of Allergy, Asthma & Immunology | volume = 76 | issue = 5 | pages = 440–446 | date = May 1996 | pmid = 8630718 | doi = 10.1016/s1081-1206(10)63461-8 }}</ref><ref>{{cite journal | vauthors = Jobst S, van den Wijngaart W, Schubert A, van de Venne H | title = Assessment of the efficacy and safety of three dose levels of cetirizine given once daily in children with perennial allergic rhinitis | journal = Allergy | volume = 49 | issue = 8 | pages = 598–604 | date = September 1994 | pmid = 7653736 | doi = 10.1111/j.1398-9995.1994.tb00125.x | s2cid = 46312788 }}</ref>

:[[File:Cetirizine synthesis.png|500px]]

Cetirizine is available as a [[combination medication]] with [[pseudoephedrine]], a [[decongestant]].<ref>{{cite journal | vauthors = Wellington K, Jarvis B | title = Cetirizine/pseudoephedrine | journal = Drugs | volume = 61 | issue = 15 | pages = 2231–2240 | date = 2001 | pmid = 11772135 | doi = 10.2165/00003495-200161150-00009 | s2cid = 263997602 }}</ref> The combination is often marketed using the same brand name as the cetirizine with a "-D" suffix (for example, [[Cetirizine/pseudoephedrine|Zyrtec-D]]).<ref>{{cite journal | vauthors = Nathan RA, Finn AF, LaForce C, Ratner P, Chapman D, de Guia EC, Hewlett D, Kramer B | title = Comparison of cetirizine-pseudoephedrine and placebo in patients with seasonal allergic rhinitis and concomitant mild-to-moderate asthma: randomized, double-blind study | journal = Annals of Allergy, Asthma & Immunology | volume = 97 | issue = 3 | pages = 389–396 | date = September 2006 | pmid = 17042147 | doi = 10.1016/S1081-1206(10)60806-X }}</ref><ref>{{cite web | title=Antihistamine/Decongestant Combination (Oral Route) Description and Brand Names | website=Mayo Clinic | date=7 February 2023 | url=https://www.mayoclinic.org/drugs-supplements/antihistamine-decongestant-combination-oral-route/description/drg-20069883 | access-date=23 February 2023}}</ref>

== References ==

Cetirizine is marketed under the brand names Alatrol, Alerid, Allacan, Allercet, Alzene, Cerchio, Cetirin, Cetizin, Cetriz, Cetzine, Cezin, Cetgel, Cirrus, Histec, Histazine, Humex, Letizen, Okacet ([[Cipla]]), Piriteze, Reactine, Razene, Rigix, Sensahist (Oethmann, South Africa), Triz, Zetop, Zirtec, Zirtek, Zodac, Zyllergy, Zynor, Zyrlek, and Zyrtec ([[Johnson & Johnson]]), ''inter alios''.<ref>{{Cite web |date=30 October 2018 |title=Cetirizine: antihistamine that relieves allergy symptoms |url=https://www.nhs.uk/medicines/cetirizine/ |access-date=23 October 2023 |website=nhs.uk |language=en}}</ref><ref>{{cite web | title = Protriptyline | work = AHFS Patient Medication Information [Internet] | location = Bethesda (MD) | publisher = American Society of Health-System Pharmacists, Inc. | date = 2019 | via = Medlineplus | url = https://medlineplus.gov/druginfo/meds/a698026.html#brand-name-1 }}</ref>{{failed verification|date=February 2023}}

=== Books and journals ===

# Anderson, P. O., Knoben, J. E., et al. (2002) ''Handbook of clinical drug data 10th ed.'' McGraw-Hill International

# Pfizer Inc, et al. (2006) ''ZYRTEC (cetirizine hydrochloride) Tablets, Chewable Tablets and Syrup For Oral Use'' Pfizer Incorporated publications

# Chetrit, E. B., Amir, G., Shalit, M. (2005). ''Cetirizine: an effective agent in Kimura's Disease'' Arthritis & Rheumatism (Arthritis care & research) Vol 53, p117-118

== ~~External links~~ ==

== References ==

*[http://www.pfizer.com/pfizer/download/uspi_zyrtec.pdf Zyrtec prescribing information] [[Pfizer]]

*[http://egeneralmedical.com/rxlist00000612.html List of brand names]

*[http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2007/ucm109025.htm US FDA approves Zyrtec-D for over the counter sales]

*[http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2007/ucm109033.htm US FDA approves Zyrtec for over the counter sales]

* [http://druginfo.nlm.nih.gov/drugportal/dpdirect.jsp?name=Cetirizine U.S. National Library of Medicine: Drug Information Portal - Cetirizine]

[[Category:Belgian inventions]]

[[Category:Acetic acids]]

[[Category:Ethers]]

[[Category:H1 receptor antagonists]]

[[Category:Drugs developed by Johnson & Johnson]]

[[Category:Peripherally selective drugs]]

[[Category:Drugs developed by Pfizer]]

[[Category:Chlorcyclizines]]

[[Category:World Health Organization essential medicines]]

[[Category:Wikipedia medicine articles ready to translate]]

[[Category:Piperazines]]

[[Category:~~Pfizer~~]]

[[Category:4-Chlorophenyl compounds]]

[[Category:Johnson & Johnson]]

[[Category:Ethers]]

[[Category:Organochlorides]]

[[Category:Carboxylic acids]]

[[da:Cetirizin]]

[[de:Cetirizin]]

[[fa:ستیریزین]]

[[fr:Cétirizine]]

[[it:Cetirizina]]

[[ka:პარლაზინი]]

[[hu:Cetirizin]]

[[nl:Cetirizine]]

[[ja:セチリジン]]

[[pl:Cetyryzyna]]

[[pt:Cetirizina]]

[[ru:Цетиризин]]

[[fi:Setiritsiini]]

[[th:เซทิไรซีน]]

[[tr:Setirizin]]

[[zh:盐酸西替利嗪]]