The Backpacker Medical Kit.
Make your own up and keep it small.
All things medical are available cheaply and plentifully on the road so there is very little point in weighing yourself down with a huge first aid kit unless you're going to be Bear Grylls-ing it off the grid for more than a few days on end.
our medical essentials.
COLD & FLU PILLS (with decongestant). They're often hard to find overseas in the same form we're used to in Western countries.
SORE THROAT. Something for that, ditto the reason above.
WOUND CARE. Bandaids, antibiotic cream (like Neosporin), Hydrocortisone cream (2%) to treat insect bites, and plenty of pain killers. This isn't to say you can't get these items overseas, it's just nice to avoid trekking around a remote town looking for a bandaid if you can avoid it.
STOMACH. Immodium or other diarrhea blocker and Pepto-Bismol. Because, you know. We often ask our doctor to write a prescription for Cipro before heading somewhere, just in case. You'll take this if you think you have a situation that warrants more than bed-rest and Pepto.
CONDOMS. Because better safe than sorry and you'll know you can trust 'em (and that they're the right size).
If you feel you'll need IT.
MOTION SICKNESS PILLS. Dramamine or the like for long car/bus/boat trips or when you want to read when in motion.
ANTI-DOPAMINERGIC. Something that suppresses vomiting/nausea such as Domperidone.
ANTI-PARASITIC. Such as Tinidazole for Guardia or amoebic dysentery.
ANTIHISTAMINE PILLS. If you have allergies or to treat a bite or sting that's itchy or you need the swelling to go down quick. Just remember, these will probably make you sleepy.
SCRIPTS. If you need to carry unusual prescription medicine, check it is legal in the country you are visiting and take a photocopy of the prescription.
For ideas and details of Malaria medication see our Mosquito Survival Guide, but as a general note, this can be bought cheaply in Asia/Africa too.