Once again I am going to drop a little helpful hint,
Honesty is the best policy. Just know that some medications are going to raise a red flag with the Coast Guard. If the meds you are on are certain psychiatric medications, like sedatives or anti-depressants or anti-psychotics, the CG may or may not give you the green light to work. I am not a physician, so if this is a question for you, your best bet is to sit down with your own physician and review the CG-719k together and if you aren't clear then contact Coast Guard medical.
Don't fuck around with this. If you need to, the NMC has a phone number and a chat window where you can contact them anonymously to ask questions.
Years ago I was on such a medication, but I was taken off of it long (at least 120 days) before I made my first application for a credential, well within CG criteria for that time period. That's because I didn't need to be on it. If you are currently taking something you think may be a problem, then ask first, before you spend money- only to be rejected later on. Review that 719k for what they require of you.
There are real safety concerns with some of these meds. Read up on some of the bad accidents of late like the SEASTREAK WALL STREET (NY ferry) allision and the COSCO BUSAN allision in SF Bay. Prescription meds played a big part in both. Whether you realize it or not, some prescription meds will interfere with your cognitive abilities just enough to put you in a questionable category, so that is why everyone who is on such meds needs to review with their doctor before making application to the Coast Guard. This is for everyone's sake- yours, ours and the general public.
If you need the med(s) and do well on them, but the Coast Guard won't let you sail on them, don't put the job before your health.
Not everyone who wants to sail, should be sailing. It's a hard truth, but it's not one I care to back down from.