Levocetirizine

Levocetirizine, sold under the brand name Xyzal, among others, is a second-generation antihistamine used for the treatment of allergic rhinitis (hay fever) and long-term hives of unclear cause.^[3] It is less sedating than older antihistamines.^[4] It is taken by mouth.^[3]

Levocetirizine

Clinical data
Trade names	Xyzal, Levazyr, others
Other names	Levocetirizine dihydrochloride
AHFS/Drugs.com	Monograph
MedlinePlus	a607056
License data	US DailyMed: Levocetirizine
Routes of administration	By mouth
Drug class	Second generation antihistamines
ATC code	R06AE09 (WHO)
Legal status
Legal status	UK: POM (Prescription only) US: OTC / Rx-only[1][2]
Pharmacokinetic data
Bioavailability	High
Protein binding	91–92%[2]
Metabolism	Minimal (less than 14%, primarily CYP3A4)[2]
Elimination half-life	8 to 9 hours[2]
Excretion	Urine: 85%[2] Feces: 12.9%[2]
Identifiers
IUPAC name 2-(2-{4-[(R)-(4-Chlorophenyl)(phenyl)methyl]piperazin-1-yl}ethoxy)acetic acid
CAS Number	130018-77-8 N
PubChem CID	1549000
IUPHAR/BPS	1214
DrugBank	DB06282 Y
ChemSpider	1266001 Y
UNII	6U5EA9RT2O
KEGG	D07402 Y as salt: D08118 Y
ChEBI	CHEBI:94559
ChEMBL	ChEMBL1201191 N
PDB ligand	LCR (PDBe, RCSB PDB)
CompTox Dashboard (EPA)	DTXSID60156294
Chemical and physical data
Formula	C21H25ClN2O3
Molar mass	388.89 g·mol−1
3D model (JSmol)	Interactive image
SMILES Clc1ccc(cc1)[C@H](N2CCN(CCOCC(=O)O)CC2)c3ccccc3
InChI InChI=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)/t21-/m1/s1 Y Key:ZKLPARSLTMPFCP-OAQYLSRUSA-N Y
NY (what is this?)  (verify)

Common side effects include sleepiness, dry mouth, cough, vomiting, and diarrhea.^[3] Use in pregnancy appears safe but has not been well studied and use when breastfeeding is of unclear safety.^[5] It is classified as a second-generation antihistamine and works by blocking histamine H₁-receptors.^[6][3]

Levocetirizine was approved for medical use in the United States in 2007,^[3] and is available as a generic medication.^[4] In 2023, it was the 158th most commonly prescribed medication in the United States, with more than 3 million prescriptions.^[7][8]

Medical uses

Levocetirizine is used for allergic rhinitis.^[9] This includes allergy symptoms such as watery eyes, runny nose, sneezing, hives, and itching.^[10]

Side effects

Levocetirizine is referred to as a non-sedating antihistamine as it does not enter the brain in significant amounts and is therefore unlikely to cause drowsiness. Cardiac safety with repolarization may be better than some other antihistamines, as levocetirizine does not significantly prolong the QT interval in healthy individuals.^[11][12][13] However, some people may still experience some slight sleepiness, headache, mouth dryness, lightheadedness, vision problems (mainly blurred vision), palpitations and fatigue.^[14]

On 16 May 2025, the U.S. Food and Drug Administration (FDA) issued a Drug Safety Communication regarding a rare but severe itching, known as pruritus, that can occur after discontinuing long-term use of levocetirizine or cetirizine. This itching has been reported in patients who used these medicines daily, typically for at least a few months and often for years, and did not experience itching before starting the medication.^[15]

Pharmacology

Levocetirizine is an antihistamine. It acts as an inverse agonist that decreases activity at histamine H1 receptors. This in turn prevents the release of other allergy chemicals and increases the blood supply to the area, providing relief from the typical symptoms of hay fever. Levocetirizine, (R)-(-)-cetirizine, is essentially a chiral switch of (±)-cetirizine. This enantiomer, the eutomer, is more selective and the (S)-counterpart, the distomer, is inactive.^[16][17]

Chemistry

Chemically, levocetirizine is the active levorotary enantiomer of cetirizine, also called the l-enantiomer of cetirizine. It is a member of the diphenylmethylpiperazine group of antihistamines.^{[citation needed]}

History

Levocetirizine was first launched in 2001 by the Belgian pharmaceutical company UCB (Union Chimique Belge).^{[citation needed]}

Society and culture

Availability

In January 2017, the US Food and Drug Administration approved an over-the-counter preparation.^[18] Levocetirizine had previously received authorization by the FDA as a prescription drug in 2007, having already been brought to market throughout much of Europe.^{[citation needed]} In India, a prescription-only drug containing levocetirizine hydrochloride and montelukast is sold as Crohist MK.^{[citation needed]}

Brand names

Different brands (Actavis, Glenmark, UCB) Levocetirizine tablets and oral solution

Xyzal Tablets 5mg in Japan

Preparations of levocetirizine are sold under the following brand names:

• Xyzal /ˈzaɪˌzɑːl/ in Australia, Austria, Bulgaria, Croatia, Cyprus, Czech Republic, Finland, France, Hong Kong, Hungary, India, Ireland (also Rinozal), Italy, Japan, Lithuania, Netherlands, Poland, Portugal, Romania, Taiwan, Thailand, Turkey, The Philippines, Serbia, Singapore, Slovakia, Slovenia, South Africa, Switzerland and UK. In May 2007, the US Food and Drug Administration approved Xyzal, where it is co-marketed by Sanofi-Aventis.
• Xazal in Spain.^[19]
• Avocel, Histrine Levo, and Xybat in Indonesia
• Zobral in Cyprus.
• Levobert in India.
• Xusal in Germany and Mexico.
• Xozal in Greece.
• Degraler in Chile.
• Allevo in Egypt.
• Zilola, Histisynt, and Xyzal (UCB) in Hungary.
• Alcet, Curin, and Seasonix in Bangladesh.
• Vozet and Uvnil in India.
• T-Day Syrup in Pakistan.
• Curin in Nepal.^[20]
• Zenaro in the Czech Republic and Slovakia.
• Xuzal and Zival in Chile.
• Cezera, Levosetil, Robenan, and Xyzal in Serbia.^[21]
• Rinozal and Xyzal in Ireland.
• Xycet in Morocco.^[22]