Diphenhydramine tablets are commonly used clinically and belong to the ethanolamine class of antihistamines, which can effectively inhibit allergic reactions, and can cross the blood-brain barrier and have a strong inhibitory effect on the patient’s central nervous system, and can play an antiemetic role. So in clinical use can be used for allergic rhinitis, allergic eczema, allergic drug rash, and if the patient has asthma can also be treated with this drug, but need to be combined with aminophylline, ephedrine. If the patient needs to do general anesthesia surgery is particularly irritable, this situation can be treated with the application of benadryl tablets sedation. There is also the time in the car or boat due to frequent motion sickness, you can also consider the application of this drug for prevention, and pay attention to life more exercise to improve resistance.