It's odd, as many pharmacists are now extremely @sey at prescribing the red top optrex drops if they 'don't think your infection is bad enough'. Now I assume this is a kind of one man at a time attempt to limit antibiotic resistance, but with that in mind, it would seem strange for a GP to prescribe these drops in the absence of there being an infection.
So Rocky - are you sure it is just a stye, or are there symptoms of an infection as well - discharge, itchiness, feeling 'something's in the eye'?