Levocetirizine

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. 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.

It is claimed to be more effective and with fewer side effects than the second generation drugs; however, this claim is not clearly supported by the available clinical literature.

History & formulations

Levocetirizine was first launched in 2001 by Belgian pharmaceutical company UCB with the brand name Xyzal in the UK, Ireland, Austria, France, The Netherlands and Romania, Xuzal in Mexico, and Xusal in Germany and Xozal in Greece. In India, levocetirizine is marketed by GlaxoSmithKline under the brand name Vozet. On May 25, 2007, the United States Food and Drug Administration approved Xyzal, where it is co-marketed by Sanofi-Aventis.

It is available as 5mg strength tablets and a 0.5mg/mL oral solution.

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.

Research

Latest research shows levocetirizine reduces asthma attacks by 70% in children.

Availability

Although the drug was only authorized by the US FDA on 25 May 2007 U.S., it is already available in most European countries. Based on previous pricing patterns for new drugs, it will likely enter the market at a higher price than currently available third and second generation antihistamines.