benadryl is very effective for hives because of the fast onset of the medication but only lasts about four hours. zyrtec tends to be slower in onset but lasts longer (24 hours). both are antihistamines of course and most of the time you only need one of the other. on some occasions however when you have taken zyrtec in the 24 hours you can still get hives so it is safe to take a dose of benadryl. benadryl does cause sedation so please be careful if you need to drive.
can i take benadryl with zyrtec. my wife has hives on her chest and arms that just poped up last night.