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 less sedative and the (S)-counterpart, the distomer, is inactive. 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. 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 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 approved Xyzal, where it is co-marketed by Sanofi-Aventis. 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.
Oxycodone/paracetamol, sold under the brand name Percocet among others, is a combination of the opioid oxycodone with paracetamol (acetaminophen), used to treat moderate to severe pain. In 2019, it was the 59th most commonly prescribed medication in the United States, with more than 11 million prescriptions. History
The United States Food and Drug Administration (FDA) first approved Percocet in 1976, under application ANDA 085106. Implicated in deaths
On June 30, 2009, an FDA advisory panel recommended that Percocet, Vicodin, and every other combination of acetaminophen with narcotic analgesics be limited in their sales because of their contributions to an alleged 400 acetaminophen-related deaths in the U.S. each year, that were attributed to acetaminophen overdose and associated liver damage.In December 2009, the Canadian Medical Association Journal reported a study finding a fivefold increase in oxycodone-related deaths in Ontario (mostly accidental) between 1991 and 2007 that led to a doubling of all opioid-related deaths in Ontario over the same period.In March 2017, U.S. President Donald Trump initiated the Opioid and Drug Abuse Commission. In July 2017, an interim report was published. Some excerpts:

References
External links
"Acetaminophen mixture with Oxycodone". Drug Information Portal. U.S. National Library of Medicine. "Prescription Acetaminophen Products to be Limited to 325 mg Per Dosage Unit; Boxed Warning Will Highlight Potential for Severe Liver Failure". U.S. Food and Drug Administration. 13 January 2011. "FDA warns about several safety issues with opioid pain medicines; requires label changes". U.S. Food and Drug Administration. 22 March 2016.