Hi garthc, I was diagnosed with Ph+CML in Jan. 2024, confirmed through bone marrow biopsy and aspiration. The first clue to this diagnosis was a very high platelet count (over 2000) and in Nov. 2023 the hematologist put me on Hydroxyurea 500 2x day to lower the platelets. After the bone marrow biopsy confirmed CML, I joined a clinical trial and began taking Tasigna, 2 150 mg capsules twice a day. Just recently, about one month ago, after taking Tasigna daily for the last six months, I developed tendonitis in my right arm. At first I attributed the very painful tendonitis to overuse since I was in the process of moving and using that arm more than usual. However, I noticed that the possible side effects included muscle pain and swelling and wondered if that was the cause, or at least a contributor to the condition. I will see my oncologist next week and will inquire. What did your doctor say? For me, it's hard to discern if the tendonitis is a simple overuse injury (I'm almost 77 and as we age tendons lose some elasticity and are more easily injured, so I've read) or if the medication, Tasigna, is the culprit. I saw a local doctor about my arm pain and he said tendonitis takes a long time to heal, that about the only relief is to rest my arm (difficult to achieve when it's your dominant side) and take Advil or Tylenol pain relievers, which help somewhat. I sympathize. It's a very painful condition.