Diphenhydramine hydrochloride has additive effects with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc).
<Diphenhydramine hydrochloride, effect, alcohol>, <Diphenhydramine hydrochloride, effect, CNS depressants>, <Diphenhydramine hydrochloride, effect, hypnotics>, <Diphenhydramine hydrochloride, effect, sedatives>, <Diphenhydramine hydrochloride, effect, tranquilizers>