Toladryl is a derivative of Diphenhydramine that can cross the blood-brain barrier and exhibits oral activity, with antihistamine and anticholinergic properties. Its anticholinergic effects are approximately a tenth of those seen with Diphenhydramine, yet it offers 2-4 times the protection against lethal doses of histamine in guinea pigs. The side effects of Toladryl are fewer and milder compared to Diphenhydramine, however, at higher doses, it may cause symptoms such as insomnia, agitation, and disorientation related to the central nervous system. Toladryl is utilized in the research of allergic diseases.
