Is it safe to take benadryl (diphenhydramine) and zyrtec together? i was put on zyrtec for an allergic reaction with steroids for swelling and it's keeping me awake.

Zyrtec (cetirizine) not the cause: It's unlikely that Zyrtec is keeping you awake. If anything, it usually causes drowsiness. You can take one dose of Benadryl (diphenhydramine) with Zyrtec, although it's not usually recommended as it may cause dizziness or excess sedation.

Steroids: Is what's keeping you awake, take them in the morning, you can try benadryl (diphenhydramine) at night, don't exceed recommended dosage as you are already on zyrtec