Leukemia
"Having tried bith Imatinib and Nilotinib, my Haemotologist tried me on Dasatinib - the effect this drug had on me was devastating, after only 3 days my body literally began to shut down, I was so weak I was crawling on my hands and knees just to go to the bathroom. 
After two weeks off it was decided to try a greatly reduced dosage (50mg) every other day but even at that I had little to no quality of life. 

I hope others have had better luck than I did."