My first aid kit (for wilderness trekking in the United States) contains:
- Acetaminophen (Tylenol) -- pain killer
- Ibuprofen (Advil) -- swelling, inflammation, pain
- Benadryl -- allergic reactions
- Tums -- Heartburn
- Pink bismuth tabs (Pepto Bismol) -- Extreme heartburn, diarrhea, upset stomach
- Immodium -- diarrhea (only one dose)
- Triple antibiotic ointment (Neosporin) -- cuts/scrapes
I don't carry much of any of these, except occasionally I'll throw in an extra travel-sized tube of Tylenol if I've had a problem recently.
In spring I'll add an allergy medicine like Allegra.
If I have a cold, I'll add a cold medicine like DayQuil. I don't carry NyQuil because I very rarely need a sleep aid.
I carry a few adhesive bandages, a couple butterfly closures, an elastic bandage, and a gauze pad, but most of what I need are medicines.