Can benadryl be taken with promethazine cough syrup?

Promethazine (Brand Name: PHENERGAN) Diphenhydramine (Brand Name: BENADRYL) These medications can safely be taken in combination therapy together. Phenergan is widely used to treat nausea/vomiting and comes in an injectable, suppository and pill form and can only be obtained with a prescription. Benadryl, commonly used for Allergies (itchy eyes, runny nose,sneezing) Benadryl can be bought over the counter for as needed use. Just follow your Doctors orders with Phenergan and the label directions with Benadryl.