Benadryl Allergy & Sinus Headache. Generic Name: acetaminophen, diphenhydramine, and phenylephrine (a SEET a MIN oh fen, DYE fen HYE dra meen, and FEN il EFF rin) Does your dog have anxiety? As any pet owner knows, dogs have personalities and behaviors for different situations. When they’re in their comfort zone, they may be relaxed and mild-mannered, but when agitated, they may become defensive, rowdy, or anxious. I have had hives for a day & a half. I would like to know if this could be related to nerves. I don't have any food allergies. I went to the doctor yesterday, she gave me a shot of Epinephrine. Explains the medication diphenhydramine (Benadryl), a drug used for the relief of nasal and non-nasal symptoms of various allergic conditions such as seasonal hay fever, allergic conjunctivitis, insomnia, and motion sickness. Benadryl (diphenhydramine) is an antihistamine used to treat allergies, hives, insomnia, motion sickness, and mild cases of Parkinsonism. Benadryl is available in generic form and over-the-counter. Common side effects of Benadryl include: Benadryl (diphenhydramine), Celexa Using diphenhydramine together with citalopram may increase side effects such as dizziness, drowsiness, and difficulty concentrating. When allergies or anxiety takes over your pet, you know how hard it is to watch them go through that pain. However, there is a solution: Benadryl for dogs. Benadryl (Diphenhydramine) is great for allergies, but curl up on the couch after taking it and get ready for a nap. Valium (diazepam) is effective for occasional or short-term use for anxiety and muscle spasm. Compared to similar drugs, Valium (diazepam) acts very quickly but can have interactions with other medicines. Benadryl (Diphenhydramine) medication blocks the actions of histamine, a naturally occurring substance in the body that causes allergy symptoms. Formication is the feeling of insects crawling across or underneath your skin. The name comes from the Latin word “formica,”which means ant.