How can I safely choose medicines during pregnancy? No medication is 100 percent safe, and even medication that's safe for someone else to take during pregnancy might not be safe for you. Benadryl is an over-the-counter medicine that can be given to dogs. Diphenhydramine, the most common active ingredient, is an H 1 antagonist, which means it helps to prevent the uptake of histamine (a type of substance responsible for allergic reactions) by receptors in the body. Hi all, I am a Paramedic and a Mom. Its ok to give Benadryl to your child. We give it in the field all the time. The dose is 1 mg/kg. To convert lbs. to kgs., take your child& 39;s weight in lbs. and divide it by 2.2 and that will give you what he/she weighs in kgs. I wouldn't take Benadryl with Seroquel. I have been diagnosed with ptsd and bipolar, and insomnia, when I took the X-ray 200 pill of Seroquel, I slept for almost a day and a half and if was the first time that I ever took the pill. Benadryl is a brand name for diphenhydramine, an antihistamine. Doctors recommend Benadryl and other diphenhydramine products to treat the symptoms of allergy or hay fever such as a runny nose. How safe is Benadryl for dogs? This is a super common question among dog owners. One of the main reasons why people ask this question is because Benadryl is not made for dogs. It is acceptable, the max daily dose is 100mg per dose or 300mg per day. However using antihistamines for sleep is only effective for a few weeks because you will gain tolerance for it. Find patient medical information for Benadryl Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Is Benadryl safe for dogs? Benadryl is safe for use in the treatment of dogs suffering from insomnia, allergies and various other canine conditions. Generally speaking using Benadryl for dogs is very safe. Even in situations where the dog is having trouble sleeping Benadryl might be a great solution.