Tamoxifen Tamoxifen Anastrozole
MajorWhen Anastrozole is taken together with Tamoxifen by breast cancer patients, the amount of Anastrozole in the blood falls by about 27%. The ATAC trial found this and also showed how the two medicines behave in the body. Because of this, Tamoxifen should not be given together with Anastrozole.
These medicines can affect each other in a serious way. Do not start taking them together unless your doctor has said it is OK. If you already take both, do not stop either one on your own: speak to your doctor or pharmacist soon.