First aid - what to bring

Hello,
Ok, this might be a silly post, but being our first time to PV, and reading the other trip posts, I am going to prepare a little first aid bag. The following is what I plan on putting in the bag. If you think that we should add anything else, based on your experiences, please reply.
-Advil
-sunscreen
-after sun lotion
-bug repellant
-Tylenol
-alcohol pads
-amonia (for any jellyfish stings)
-beach shoes (only for use in the water)

Thanks for your help!

What are \"beach shoes\" exactly? Neoprene slip ons?

add anything else, based on your experiences

needle and thread (to sew up them nasty gashes) allergy meds (claritin, etc) and some Preparation H.

Bandaids we had to by some down there and I dont know if it was the store (pharmaca) but the cost was around 80 peso for a small box which I thought waas really expensive but at the time needed them bought them :)

Imodium AD-- diarrhea
Triple antibiotic ointment (Neosporin)--any minor skin lesion or minor
infection
Band-aids
Benadryl 25mg kapsules and Benadryl antihistamine cream
Advil or ibuprofen or Tylenol-aches, pains, fever
zip-loc bags to make quick ice packs
safety pins
needle and thread