Hi, Xevor (Levocetirizine) is an antihistamine medication that is commonly used to treat allergic symptoms such as sneezing, runny nose, itching, and hives. Drowsiness is a known side effect of Xevor, although it is not experienced by everyone who takes it. If you have been experiencing drowsiness since taking Xevor, it may be due to this side effect. However, it is also possible that other factors could be contributing to your drowsiness. It is important to talk to your doctor about any side effects you experience while taking Xevor, including drowsiness so that they can evaluate whether the medication is the cause and recommend any necessary adjustments to your treatment. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician