When I was undergoing radiation for cancer two years ago, I threw up every day for a month. It was horrible. The pills my radiation oncologist prescribed didn't seem to do anything. I was in agony for much of every day, incredibly hungry but also unbearably nauseous and unable to hold much down. My doctor hinted that I should try smoking marijuana, so I did. (Somehow, it hadn't already ocurred to me.)
It really did seem to work, and I smoked more or less every other day for the rest of my treatments. (Well, I smoked it every day for a while, and slowed down to experiment with the difference as the symptoms subsided in general a bit. I guess I wasn't feeling very scientific when I spent such a large part of every day praying to the porcelain goddess.) I still threw up, but not quite as much and I didn't seem to feel as bad for the rest of the day, though it's hard to separate those effects from the effects of psychological suggestion and the fact that I was distracted by my altered mindstate.
I also tried taking Marinol pills, which contain extracts of some of the medicinal components of marijuana, with little of the narcotic power. Those seemed to work even better, which should make sense if you listen to the anti-medicinal marijuana folks, who insist that pot smoke doesn't have as much of the healing stuff in it as the raw plant does.