Centrum drops, whose main drug component is the antihistamine cetirizine hydrochloride, are mostly used in adults and children with rhinitis or allergies due to urticaria, as selective histamine H1 receptor antagonists, mainly to antagonize seasonal and perennial allergic rhinitis, as well as symptoms of urticaria or itchy skin due to allergies. However, there are certain side effects, including drowsiness, dizziness, vertigo and dry mouth, so it needs to be contraindicated or used with caution in children of young age and professionals doing delicate work when taking the drug.