Dear Roz,
I think your pain is from the Arimidex. I had talked with people when I was taking radiation for my spine, one of the ladies said her mother had terrible joint pain from the Arimidex. I don't think it's from the Herceptin unless it's from taking the two close together. Ask your onc what he thinks. I think in time they are going to put me on Arimidex, hope I won't have such side effects. As far as the Herceptin I have no pain, the only pain I have is in my spine and it's from the location of the malignant tumor that was radiated.
Keep me informed of your progress. And a healthy and happy new year to you.
hugs,
ginkott1@aol.com