in over the counter stuff, I find it helpful...the decongestant works faster than the antihistamine, sometimes by up to an hour. Decongestants treat different symptoms - without getting technical into what they do, antihistamines can't do anything about what's already happened. They just keep anything else from starting. Decongestants fix the stuff that's already happening. By the time you *feel* stuffy, it's already too late - the histamines have bonded with the allergens. It can take up to 2 hours for an anti-histamine to provide relief. In the interim, the decongestant fixes it so that you can at least breathe.
(no subject)