Judging by the description of the product:
"Medic is a highly effective treatment for external fish parasites present in both marine and freshwater environments. It contains an antibiotic component and a reef-safe oxidizing agent that work together to help eliminate parasites."
Your UV is performing the same task. I'd turn it back on. Additionally, a UV light can also generate ozone in the tank thereby introducing "oxidizing agents." And it has the nice proven ability to kill parasites when running. Any "oxidizing agents" presented by the medication are going to do just that, oxidize. Their oxidizing life will be relatively short lived by their very nature and will tend to oxidize *any* organic compound and not just target parasites.
Most antibiotics will be taken out by skimming as they react ionically in a similar way as the organic material in your tank. However, ich being a parasite, antibiotics aren't going to make a difference other than preventing a secondary infection. Antibiotics can also affect your good bacteria in a negative way.
I'd say improve the water quality as much as you can until it tests perfect. Also following the recommending dosing of garlic extreme and vitamin C can help.
Best method is to catch all the fish out from the main tank and put them in a QT dosed with copper sulfate.
Good luck.
