Carbon filter media and meds?

one of my dear goldies has fin rot. so i'm treating the whole tank. but before i added the med i forgot to take the carbon out of the filter. i remembered just 30 min later and i took it out. is that long enough for the carbon to ruin my med. effect? and i couldn't 100% clean my filter and the sponges off carbon is that ok? i need answers please i love my goldfish more than anything.