i disagree that the caffeine is to deter abuse. as it is, phrenilin and phrenilin forte are rarely ever abused vs
. fioricet. caffeine, as everyone knows, is addicting...but coming from someone with lots and lots of experience abusing this medication....the caffeine is there to keep you from getting knocked out, thus improving your 'high'....you get high, drunk, relaxed, and experience euphoria, all without the inconvenience of being knocked out during it. that's the true purpose of the caffeine.