Levocetirizine Dihydrochloride Pellets
Systematic (IUPAC) name:
2-[2-[4-[(R)-(4-chlorophenyl)-phenyl-methyl] piperazin-1-yl]ethoxy]acetic acid
Molecular Formula:

Levocetirizine (as levocetirizine dihydrochloride) is a third-generation non-sedative antihistamine, developed from the second-generation antihistamine cetirizine. Chemically, levocetirizine is the active enantiomer of cetirizine. It is the L-enantiomer of the cetirizine racemate. Levocetirizine works by blocking histamine receptors. It does not prevent the actual release of histamine from mast cells, but prevents it binding to its receptors. This in turn prevents the release of other allergy chemicals and increased blood supply to the area, and provides relief from the typical symptoms of hayfever.

The manufacturers claim it to be more effective with fewer side effects than the second-generation drugs; however, there have been no published studies supporting this assertion.
Side effects:
Levocetirizine is called a non-sedating antihistamine as it does not enter the brain in significant amounts, and is therefore unlikely to cause drowsiness. However, some people may experience some slight sleepiness, headache, mouth dryness, lightheadedness, vision problems (mainly blurred vision), palpitations and fatigue.
Latest research shows levocetirizine reduces asthma attacks by 70% in children.
The drug is currently available on prescription in the United States. Although the drug was only authorized by the FDA on 25 May 2007, it was already available in most European countries. As for many new drugs it entered the market at a higher price than currently available third- and second-generation antihistamines. In India, one form of the drug is available as "LevoKast" tablets, marketed by [TTK Healthcare Ltd]. The "LevoKast" is a formulation of Levocetirizine Hydrochloride & Montelukast. The "LevoKast" is a Schedule 'H' Drug and can be taken on the prescription by a Registered Medical Practitioner only.