Abstract
Patients on tyrosine kinase inhibitor therapy for chronic myeloid leukemia are often found to have elevated creatinine kinase levels on routine bloodwork and are asymptomatic. Here we report 4 cases of significant acute symptomatic jumps in levels with associated rhabdomyolysis that resolved with drug cessation. Etiology of the acute jumps is not known and this finding does not appear to be related to any one specific tyrosine kinase inhibitor, as 4 different tyrosine kinases were involved.