Levocetirizine, sold under the brand name Xyzal among others, is a second-generation

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provid ...

used for the treatment of

allergic rhinitis Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, i ...

(hay fever) and long term hives of unclear cause. It is less sedating than older antihistamines. It is taken by mouth. Common side effects include sleepiness, dry mouth, cough, vomiting, and diarrhea. Use in

pregnancy Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occur ...

appears safe but has not been well studied and use when

breastfeeding Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that br ...

is of unclear safety. It is classified as a second-generation antihistamine and works by blocking histamine H₁-receptors. Levocetirizine was approved for medical use in the United States in 2007. It is available as a generic medication. In 2020, it was the 179th most commonly prescribed medication in the United States, with more than 3million prescriptions.

Medical uses

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

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. However, some people may still experience some slight

sleepiness Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...

, headache, mouth dryness,

lightheadedness Lightheadedness is a common and typically unpleasant sensation of dizziness or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may feel ...

, vision problems (mainly blurred vision), palpitations and fatigue.

Pharmacology

Levocetirizine is an

. It acts as an inverse agonist that decreases activity at

histamine H1 receptor The H1 receptor is a histamine receptor belonging to the family of rhodopsin-like G-protein-coupled receptors. This receptor is activated by the biogenic amine histamine. It is expressed in smooth muscles, on vascular endothelial cells, in the h ...

s. 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 The word "chiral switch" was introduced by Agranat and Caner in 1999. Chiral switches are chiral drugs that are already approved as racemates but that have been re-developed as single enantiomers. The term chiral switching has been coined to descr ...

of (±)-cetirizine. This enantiomer, the

eutomer The eudysmic ratio (also spelled eudismic ratio) represents the difference in pharmacologic activity between the two enantiomers of a drug. In most cases where a chiral compound is biologically active, one enantiomer is more active than the other ...

, is more selective and less sedative and the (S)-counterpart, the distomer, is inactive.

Chemistry

Chemically, levocetirizine is the active levorotary enantiomer of

cetirizine Cetirizine, sold under the brand name Zyrtec among others, is a second-generation antihistamine used to treat allergic rhinitis (hay fever), dermatitis, and urticaria (hives). It is taken by mouth. Effects generally begin within thirty minutes a ...

, also called the ''l''-enantiomer of cetirizine. It is a member of the diphenylmethylpiperazine group of antihistamines.

History

Levocetirizine was first launched in 2001 by the Belgian pharmaceutical company UCB (''Union Chimique Belge'').

Society and culture

Availability

On 31 January 2017, the

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

approved an over-the-counter preparation. Levocetirizine had previously received authorization by the FDA as a prescription drug in 2007, having already been brought to market throughout much of Europe. In India, a prescription-only drug containing levocetirizine hydrochloride and montelukast is sold as Crohist MK.

Brand names

Preparations of levocetirizine are sold under the following brand names: * Xyzal in Australia, Austria, Bulgaria, Croatia, Cyprus, Czech Republic, Finland, France, Hungary, India, Ireland (also Rinozal), Italy, Japan, Lithuania, Netherlands, Poland, Portugal, Romania, Taiwan, Thailand, Turkey, The Philippines, Serbia, Singapore, Slovakia, Slovenia, South Africa, Spain, Switzerland and UK. On May 25, 2007, the

United States Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food s ...

approved Xyzal, where it is co-marketed by

Sanofi-Aventis Sanofi S.A. is a French multinational pharmaceutical and healthcare company headquartered in Paris, France. Originally, the corporation was established in 1973 and merged with Synthélabo in 1999 to form Sanofi-Synthélabo. In 2004, Sanofi-Syn ...

. * 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. * Zenaro in the Czech Republic and

Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the s ...

* Xuzal and Zival in Chile * Cezera, Levosetil, Robenan, and Xyzal in Serbia. * Rinozal and Xyzal in Ireland

References

External links

* * {{Portal bar , Medicine Acetic acids Belgian inventions Benzene derivatives Chloroarenes Enantiopure drugs Ethers H1 receptor antagonists Peripherally selective drugs Piperazines Wikipedia medicine articles ready to translate