Background: Muscle-related complaints and high creatine phosphokinase (CPK) blood levels have been reported in 15-50% of patients with acne treated with isotretinoin. Clinical investigations about CPK levels in isotretinoin therapy were few, and most of them were case reports. The aim of this study was to investigate the incidence, course, and clinical significance of severe hyperphosphokinasemia in isotretinoin therapy for acne.
Methods: A total of 89 patients were treated with isotretinoin for moderate or severe acne at our dermatology department. At the initial visit and during the monthly follow-up visits, hemoglobin, hematocrit, leukocytes, thrombocyte, renal function tests (urea and creatinine), direct and indirect bilirubin, liver enzymes [serum glutamate oxaloacetate (SGOT), serum glutamate pyruvate transaminase (SGPT), gamma glutamil transpeptidase (GGT), and alkaline phosphotase (ALP)], lipid profile [total cholesterol, very low density lipoproteins (VLDL), low density lipoproteins (LDL), high density lipoproteins (HDL), and triglycerides], urine analysis, and CPK were requested. We asked all patients about muscle-related complaints, weakness, exercise, and compared CPK levels.
Results: Elevated CPK levels were recorded in only five patients during treatment period. Maximum serum CPK values recorded for each patient ranged between 292 and 569 IU/l. Only one patient out of five had myalgia and four patients were completely asymptomatic.
Conclusions: In conclusion, marked hyperCPKemia with or without muscle-related complaints in isotretinoin-treated patients with acne is a benign phenomenon; therefore, it is logical to reserve measurement of CPK levels as well as renal tests for cases with severe muscle pain.