I took this during a clinical trial comparing Tykerb to Herceptin. I was supposed to take this for a year, but after two weeks I had to stop. I was exhausted to the point I could not get out of bed. My diaherra was so severe that I could not eat at all (not even crackers or popscicles). Finally, after losing 13 pounds in two weeks and becoming so dehydrated that they had to give me two bags of fluids, I was taken off the drug and given Herceptin by IV for the rest of the year. I have one more treatment left. I have been very happy with Herceptin. It has hardly any side effects. I think Tykerb works for some people, but if your side effects are this severe, please make your doctor change your meds! It was worse than the 20 weeks of chemo!