Actually, all joking aside, I also have an allergy to chloramphenicol ointment, so I use eye drops that are dispensed in Minims. I think that the allergy is to the preservatives rather than the chloramphenicol.
(Gareth is, of course, right about exchanging medicine. When I was working in Aberdeen we had no Pharmacy in our area, so we offered a service to the older and less mobile people who lived nearby. They would come to our coffee lounge and hand over their prescriptions. Somebody would drive to the pharmacy with all these scripts and have each of them filled, returning to the coffee lounge social gathering with a basket full of pills and potions. The really scary thing was when the old ladies started exchanging stories about their various ailments and recognizing similarities.
Aberdeen Oldies wrote:"I had the very same thing, myself. My Doctor gave me these pills, they were marvellous. Cleared my up in no time. Take these and try them."
I would tell them not to do it, but I am pretty sure that whenever they were out of the coffee lounge they would go back to swapping pills.)
Andrew