You should not use Benadryl if you are allergic to diphenhydramine. Ask a doctor or pharmacist if it is safe for you to take this medicine if you have other medical conditions, especially: blockage in your digestive tract (stomach or intestines); Can you drink alcohol while taking antihistamines? Medical news mixer nixers top 10 drinking dangers webmd. Lisa should i stop using benadryl to help me slee. Benadryl is a strong drug. Using it safely means not drinking alcohol while you take it. Combining the drug with alcohol can cause dangerous effects, such as extreme drowsiness and impaired motor. Benadryl While Pregnant Is it safe to take Benadryl when pregnant? Benadryl is a class B drug according to FDA. Just like other antihistamines such as Allegra, Claritin, and Zyrtec you can safely take Benadryl during pregnancy. Can you get addicted to Benadryl? Yes, you can get addicted to Benadryl. But it's rare. When do you develop tolerance to the sedative effects of diphenhydramine? Comprehensive alcohol & food interactions for Benadryl (diphenhydramine). Drugs.com provides accurate and independent information on more than 24,000 prescription drugs, over-the-counter medicines and natural products. If you decide to drink, take each glass at a time and determine how these agents affect you. Do not take too much at one time especially if you are not used or have not learned yet alcohol effects on you. Cho remarks on whether or not you can drink alcohol while taking Benadryl. If you do drink it is best to limit it to one drink only. One drink is considered one 12 oz beer, one 4 oz glass of wine or one 1.5 oz of hard liquor. One drink is considered one 12 oz beer, one 4 oz glass of wine or one 1.5 oz of hard liquor.