Question: what is the difference between cetirizine and levocetirizine?
Answer: Previous research suggested that levocetirizine is less sedating than cetirizine, and that 2.5 mg of levocetirizine is equivalent to 5 mg of cetirizine. levocetirizine is the R-enantiomer of cetirizine, and the investigators hypothesized that it would be more potent.