Common adverse reactions of levocetirizine hydrochloride oral solution include drowsiness, dry mouth, headache, and weakness, etc. The adverse reactions are mild and tolerable and do not require discontinuation of the drug. Levocetirizine hydrochloride oral solution is an anti-allergic drug, mainly used for the treatment of allergic diseases, such as urticaria, eczema, dermatitis, itchy skin, allergic rhinitis, etc. Although Levocetirizine hydrochloride oral solution has mild adverse reactions, there are several points to note when taking it: First, it should not be taken after alcohol to avoid aggravating liver damage. Second, because of the adverse effect of drowsiness, avoid working at height, driving or manipulating machines after taking the drug to avoid danger. Third, should be avoided in combination with sedatives such as Sulezade, in order to avoid aggravating the adverse effects of drowsiness. Fourth, pregnant and lactating women are prohibited. Fifth, hepatic and renal insufficiency and the elderly should be used with caution.