Hello all, I too have suffered greatly from debilitating headache which appears directly related to aromatase inhibitors. I searched numerous BC sites repeatedly for reasons and fixes to help me stay on the medication. I worked with my oncologist, neurologist and nurse practioner to leave no stone uncovered. Over the next 18 months I had two CAT scans, 3 aromotase inhibitor holidays of two weeks duration each and numerous medical grade headache medications. I also kept a daily headache journal. It became evident that a strong pattern repeated itself over many 12 to 14 week periods. I tried each AI type and alternate brands of Arimedex. The headache would only resolve when I discontinued the drugs, slowly disappearing by about 20% per day over 5 or 6 days. The pattern of occurrence and then disappearance was almost exactly the same each time, repeating itself four times. My oncology team could no longer in good faith, prescribe aromatase inhibitor drugs to me, as the mechanism of action for each of them is virtually the same. At this point my oncologist suggested I try Tamoxifen. Despite being postmenopausal, and with a grade 3 IDC and extensive LVI, I agreed. It has come with its own side effects but they are tolerable. As my team reminds me, the "best drug is the one you can take as prescribed and stay on". I have now been on Tamoxifen for over 3 years. I am advised to try to get to ten years of combined drug therapy, and I now believe it will be possible.