Guest: Douglas Jones, MD A recent study was done to show the side effects of diphenhydramine for allergic reactions, and one of the main detriments was that it could impair the patient by making them tired or sleepy. Another finding was that it doesn’t work that quickly, so in turn, giving diphenhydramine in a severe allergic reaction could cause more harm than good. To learn more on what you should know before using diphenhydramine in allergic reaction situations and possible better solutions, tune in with Dr. Douglas Jones, Board-Certified Allergist and Immunologist with the Tanner Clinic in Layton, Utah.