Anastrozole
"I took one pill. ONE. Within 12 hours I began itching from head to toe. In 24 hours I was in the emergency room with a terrible rash all over me. It was so bad and it was raised so high you could almost measure it with a ruler! I didn't want to scratch first. I had to get two shots in my belly, was put on oral prednisone for two weeks (which then calls for a slow wean-off of the drug), a prescription topical medicine and over-the-counter medicines. The rash hung around for almost three weeks. I'm allergic to sulfa and all NSAIDS, but my doctor wasn't sure what is in this drug to cause this reaction. He put me on tamoxifen next, which I took for 7 years but the cancer came back. I am now on letrozole with no problems except joint pain."