Diphenhydramine Hydrochloride refers to Diphenhydramine Hydrochloride Tablets, and its side effects include neurological reactions, gastrointestinal reactions, and episodic reactions. 1. Neurological reactions: Difenidol Hydrochloride Tablets are clinically used to treat symptoms such as vertigo and nausea, which can cause side effects such as drowsiness, headache, hallucinations and dizziness. 2. Gastrointestinal reactions: patients taking the drug can cause dry mouth, gastrointestinal discomfort, and may even lead to nausea, vomiting and other symptoms. 3. Episodic reactions: Skin rashes and transient hypotensive reactions may also be seen occasionally after taking the drug. Contraindications: It should be noted that infants under 6 months of age are prohibited; renal insufficiency patients are prohibited; allergic to the product is prohibited, allergic individuals should be cautious. Precautions: Glaucoma, gastric ulcer or urinary tract obstructive disease and sinus tachycardia patients should be used with caution; pregnant women should be used with caution; such as overdose or serious adverse reactions, should immediately seek medical attention; the product is prohibited from use when the properties of the product have changed. The above drugs need to be taken under the guidance of a doctor, do not take on your own, so as not to delay the condition.