Most of the studies reviewed used doses that were twice the recommended amount -- 50 milligrams -- of diphenhydramine, the active ingredient in Benadryl and other first-generation "sedating" allergy medications."We're not saying that there's not a difference," says lead researcher Bruce G.The difference between them is really blurred." "Under some circumstances, the nonsedating formulas do cause sedation and in some cases, these sedating formulas do not," he tells Web MD."In some studies we reviewed, some people actually experienced more sedation with the newer, nonsedating formulas than with the older, sedating products.According to a report of a patient in the Journal of Child and Adolescent Psychopharmacology in 2010, DPH is abused for its sedative, sleep-inducing, and euphoric effects on the central nervous system.The antihistamines cause addiction by increasing dopamine release in the brain's reward and pleasure centers, typical of addictive substances such as Vicodin and heroin.Most cases of allergic rhinitis respond to pharmacotherapy.
However, if you take the older (first generation), sedating antihistamines in higher doses for a prolonged time, you run the risk of physical dependence and addiction, as well as more severe adverse side effects." April 25, 2003 -- Timely research for the start of hay fever season: Despite their higher cost, the newer, so-called "second generation" of more expensive "nonsedating" prescription antihistamines may be no more effective at preventing fatigue and memory lapses than older over-the-counter formulas such as Benadryl.So concludes a new study published in the current issue of Journal of Allergy and Clinical Immunology in which researchers compared 18 previous trials investigating antihistamine-caused sedation levels in 1,500 people between ages 8 and 81.Often referred to as the nonsedating antihistamines.They compete with histamine for histamine receptor type 1 (H1) receptor sites in the blood vessels, GI tract, and respiratory tract, which, in turn, inhibits physiologic effects that histamine normally induces at the H1 receptor sites.