Musculoskeletal complaints are a common side effect of Imatinib and are manifested as muscle cramps and bone pain. The muscle cramps occur mainly in the hands, feet, calves, and thighs. The pattern, frequency, and severity of cramps are usually constant over time, and they may resemble titanic contractions. Some patients relate cramps to exertion or describe night time occurrence. Bone pain and arthralgias have been reported by 20 % to 40 % of patients. Their onset tends to be in the first month of therapy, and they frequently abate after a few months. The symptoms most frequently affect the femurs, tibias, hips, and knees. Bone or joint pain can be severe and disabling and may be strikingly asymmetric. In some cases, imaging studies were done but failed to detect abnormalities.
