Does diphenhydramine raise your blood sugar?

Benadryl contains one of several antihistamines. The antihistamine is an inhibitor of histamine. The histamine is a vasodilator produced by the body to dilate the blood vessels in the body. The antihistamine has the properties of acting as a vasoconstrictor by inhibiting the vasodilator effects of histamine. Therefore, the antihistamine constricts a little bit the blood vessels which means that it could increase the blood pressure of the individual.