Guess you should leave your fishes in when you do your water change. It causes less stress. Are the eyes of the fish popping out more than it should as well?
Before medicating, do check if your water parameters are good. If you can test it would be best =) helps eliminates some possibilities. Would you have your ammonia / nitrite reading?
Regular water changes sometimes reduce the stress levels of fishes when water quality is at the lower end. But do frequent small changes instead of a full on 100%.
When I get hit with a problem - water change is my top priority. I go as frequent as doing 15-20% almost daily when I have a problem. I’ve avoided medication to the best I can, and somehow it works for me.. so far... fingers crossed!