My own record on this stuff is not stellar. I never took antimalarials in my life untill I got to Africa. Never in South America (and I canoed from Peru to Bolivia) and never in my years in Asia. I finally, for the first time ever took them in Africa. I took docycycline and I got Malaria- YMMV
If your pain killers turn to dust, I suppose you can always snort them. I hear they do it that way as a matter of course in Colombia.