I've had this fun the last year or so in both South America and Central Asia, heck, even Europe. I have several tablets, and they all have specific brand names. Of course at the pharmacy, apteka, apteek or whatever it's called in each place, even pronunciation varying slightly causes confusion - 'Warfarin' vs 'VarfarIn' is the difference between confusion and clarity(!).
I've found the best is to show them the previous meds box / container if you have it - as they may well recognise the brand name, and failing that, the 'generic' name. Or in one case in Uzbekistan, I went on Wikipedia and searched for the drug, and found what it was called over there.
Be sure to check the dosage though, as the concentrations can vary from country to country, and make sure to check it online afterwards if they give you something that seems a bit different - I had a doctor at a hospital in Tajikistan prescribe me something completely wrong - if I'd blindly followed their instructions I'd have ended up in hospital!
I know Ankur mentions the pharmacist or doctors - but seriously, in some of these countries their advice was shocking - offering me 'calcium' supplements instead of blood thinners, quite scary to see! Worst case, have the phone number of your GP on hand, as you can give them a call and get them to look it up and confirm that it's ok.
However most 'tourist' meds - headache, stomach etc are pretty common and standard everywhere and a simple headrub with pained face, or pointing to one's stomach will usually elicit the sympathetic look and the appropriate medicine for the area :)