Fred, depends on where you dock in Cozumel. At the International pier (not the furthest from town, but the one to the left of that) there is a pharmacy as soon as you step off the pier into the shops. I know that because of what happen on our cruise last year. My 17 year old son had a bad case of streep throat and couldn't get off the ship he was so sick. I told Randy I would look for a pharmacy in Cozumel and get him something. When I went in the pharmacy almost all the medication (and they have everything - things that are only prescription here) were in spanish. I was trying to understand what the lady at the counter was explaining to me, but I wasn't up on medical terms,
so half jokingly said to the man at the counter next to me "You're not by any chance a doctor are you?" - and he say "yes, I'm an emergency room doctor." I nearly freaked out. The man was very nice and helped me find the right medication for Randy. I paid about $20.00 for a prescription spray that he said would have been much more expensive in the states. It worked great.
Be advised that the drug stores in Cozumel have really cracked down and many meds that you used to be able to buy without even a second glance they will no longer sell you with a doctors script. I used to buy 222's all the time which is basically Tylanol 3 with codine due to my fybromyalgia, the last trip a couple weeks ago I could not find any drug store willing to sell it unless I went to a Dr and got a script.