What should I know about Benadryl injection before receiving it?

Benadryl injection may be given in an emergency situation if someone is experiencing a severe allergic reaction called anaphylaxis or if it is otherwise prescribed by a doctor. Benadryl injection should not be taken by breastfeeding women because of the risk of antihistamines to infants. You should not receive Benadryl if you are taking sodium oxybate (GHB). Use Benadryl with caution if you have breathing problems, narrow-angle glaucoma, high blood pressure, sleep apnea, overactive thyroid, an intestinal block, prostate problems or difficulty urinating, ulcers, porphyria or diabetes. This drug may cause you to be dizzy or lightheaded and may increase your risk of sunburn or heat stroke. Drowsiness may increase if alcohol is consumed while using Benadryl.