Benadryl is a brand of various antihistamine medications used to stop allergies, whose content varies in different countries, but which includes some combination of diphenhydramine, acrivastine, and/or cetirizine.It is sold by Kenvue and is used to relieve allergy symptoms such as sneezing, itching, runny nose, rash, and hives.[2] Common side effects of the drug include drowsiness, dizziness, dry mouth and throat, confusion, and blurred vision.[4] Benadryl is also sold as a cough medicine in Australia, India and New Zealand containing diphenhydramine, as well as the antitussive dextromethorphan or the expectorant guaifenesin.It is an oral drug to be taken by mouth, to relieve symptoms of allergy, hay fever and the common cold.While it is not marketed as an over-the-counter (OTC) sleeping aid, most versions of Benadryl contain diphenhydramine, a drug with sedative properties.[13] Studies propose that long-term use of anticholinergic drugs is associated with an increased risk for dementia among older people.Driving, operating machinery or any other activities that require full concentration and consciousness are not recommended as these effects persist.[21] In 1943, diphenhydramine was discovered by chemist George Rieveschl and one of his students, Fred Huber, while they were conducting research into muscle relaxants at the University of Cincinnati.[29] In 2010, after the U.S. Food and Drug Administration (FDA) reported over one hundred cases of mistaken ingestion by mouth, the packaging of Benadryl Itch Stopping Gel was redesigned to include a new warning ("for skin use only"), and a sticker[clarification needed] was added as an additional precaution.A study published in the American Journal of Geriatric Psychiatry discovered that approximately one in three adults between the ages of 65 and 80 occasionally use over-the-counter drugs like Benadryl to help with sleep.[31] In May 2020, the Cook Children's Medical Center in Fort Worth, TX reported that 3 teenagers had been hospitalized as a result of diphenhydramine overdose.After a later-deleted Facebook post by the teen's family member claimed that the death was the result of a "Benadryl challenge," news outlets reported on the dangers of the supposed social media trend.