It mustve been some type of western. I was very young at the time so my memory is very foggy. This was at least 10 years ago that i saw the film.

I remember indians had a guy held captive and he need to fill a death sentence or something similar. Anyway, they held him down and blew some substance (maybe red powder) straight into his nose. which i assume was some sort of extreme psychedelic and left him to rot in the desert.  I vaguely remember them laughing right after this and his vision blurring out as they do so.