Is it okay to mix benadryl (diphenhydramine) with my other medications?

Avoid these: Older antihistamines like Benadryl (diphenhydramine) interact with many drugs. Don't mix it with alcohol, sleeping pills, sedatives, antidepressants, potassium supplements, sodium or potassium phosphate, antipsychotics, MAO inhibitors, symlin (pramlintide), sodium oxybate, Precedex (dexmedetomidine) & abilify (aripiprazole). Loratidine and fexofenadine are as effective & much safer. Discuss this with your doctor.

Depends on situation: It works ok with many other medications but can increase the sedative effect of some. Either clear the combo with your doc or try it when you don't plan to be driving or operating machinery.