These combinations are considered extremely harmful and should always be avoided.
diphenhydramine
A euphoric depressant which is prescribed as a sleep aid and sometimes to help with Alcohol detox. Also used as a recreational depressant, as a non-toxic alternative to Alcohol. Despite not having Alcohol's toxicity it is risky due to among other things inconsistent concentration in commonly sold solution form, and can be very dangerous if taken with other depressants.
These combinations are considered extremely harmful and should always be avoided.