freewillie
Contributor
Technically the only difference is in the release of the medications. The active ingredient is pseudoephedrine. It works as a vasoconstrictor causing blood vessels to contract and thereby decreasing congestion. It is subject to a high rate of tachyphylaxis - the more you use it the less effective the dose becomes. And, it is subject to rebound, when it stops working the sx come back but worse than before you took the rx. The regular version last for 4-6 hours and the 12 hour version last for, yep, 12 hours.
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Actually, the original Actifed had psuedoephedrine in it, but since 2006 the active ingredients are chlorpheneramine maleate and phenylephrine. BTW phenelephrine was discontinue as a stand alone decongestant because it was implicated in strokes in older patients taking otc cold meds.
The original Actifed triprolidine/pseudoephedrine is still available in Canada.
