I have been on tamoxifen now for 3 weeks, and after 5 days of being on this drug, i have developed chest pain and tightness.  It is not always there, seems to come and go.  However it appears to have got progressively worse over last 12 hours.  Is this likely to be a side effect of the tamoxifen, and should I contact my oncologist tomorrow about this?  I am 47 years of age, was diagnosed with breast cancer Sept. 2010.  Have had  mascetomy,chemo, radiation.  My cancer was er/pr positive 91% on pathology report. I am about 65 kgs and 1.75m in height.  Are taking Genox 20mg taxoxifen.  Appreciate your advice.  Regards Sue-Anne
Thanks for your question on Chat Doctor. I can understand your concern. Yes, all these, chest pain and chest tightness, can be the side effects of tamoxifen. Tamoxifen can cause Chat Doctor. I think, you will be alright with taking antacid