Complete Chicken Checklist?

There are no medicines I would buy for baby chicks, except possibly a small bottle of BluKote in case of bad pecking -- but if they have enough brooder space and can get away from the heat, this should not be a problem.  I just used household items -- warm water plus Vaseline for the occasional pasty butt.  Hopefully you will never need an antibiotic;  I think they are often given when they should not be.  You may want a wormer such as Valbazen when they are older, but because of expiration, you do not want to buy it ahead.  You will also eventually want some 5% Sevin garden dust, or some poultry dust or spray (usually pyrethrin/permethrin) as a llice/mite preventive, but again, that comes later.

The only "emergency" med for chicks would be Corid (amprolium,) in case they get cocci, but again, most people have no problem with this, and only after exposure to soil.  It's a bit expensive to buy "just in case."  I've never given chicks vitamins and I've never had cocci.  A little organic apple cider vinegar helps control mold in waterers but again is not necessary.

You might want to read the baby chick section i the learning center, if you haven't.

If you're using Purina's medicated starter feed you won't need the Corid, it has amprolium in it. I don't know about the other brands though. I am a fan of the Apple cider vinegar. It does help the slimy water problem, I also believe it helps with pasty butt. In my first batch of chicks, the pasty butt ended when I started using it, and I didn't get pasty butt at all with the two batches after that. I don't know if it's true with all chicks, but mine drink more water when there is ACV in it.

Everyone puts their own definitions to what is "basic". I probably do not have half of what most people consider needs to be. What you feel comfortable in spending and keeping is what you should be looking to have, that said I would not recommend keeping any sort of medication around unless the need arises to use them. It won't hurt to go get them if you recognize a problem but just carrying them on hand for a possibility is a waste in my humble opinion. Waiting that extra day or so won't make or break the health of a chick and if it does, I doubt having the medicine on hand would save it either. <---Opinion, not a vet :)