Creatine kinase elevation associated with 5-fluorouracil and levamisole therapy for carcinoma of the colon - A case report

BACKGROUND. There have been no reports of creatine phosphokinase (CK) elevation during levamisole administration. There is only one prior report of CK elevation of noncardiac origin associated with 5-fluorouracil. METHODS. A 41-year-old man was diagnosed with Stage B2 colon carcinoma and underwent extensive surgical resection. Adjuvant therapy with 5-fluorouracil and levamisole was initiated after surgery. A complete hematologic and chemistry profile was obtained during weekly clinic visits. RESULTS. The patient's serum CK levels were normal prior to the initiation of chemotherapy but began to rise after 4 weeks of therapy, Isoenzyme analysis revealed that the CK was 100% from skeletal muscle. When the CK level surpassed 1,000 U/L, chemotherapy was discontinued. The CK levels began to decline immediately, falling to normal within 2 months. All attempts to identify a known cause of the enzyme elevation were negative. CONCLUSIONS. The temporal relationship between chemotherapy administration, enzyme elevation, and the rapid fall in enzyme levels upon discontinuation of treatment argue strongly in favor of chemotherapy as the etiology of CK elevation in this patient. (C) 1996 American Cancer Society.