CLINICAL FACTORS ASSOCIATED WITH PAIN AFTER SUBCUTANEOUS ERYTHROPOIETIN INJECTION IN AUTOLOGOUS BLOOD DONORS WITH MULTIVARIATE STATISTICS

Abstract

Although subcutaneous injection of erythropoiesis-stimulating agent (ESA) is a convenient administration method, pain at the injection site remains problematic. Currently, two ESAs are available in Japan. Differences in pain have been observed between these two ESAs in several reports; however, most of the studies consisted of patients with renal failure.
To clinically determine important factors associated with pain after subcutaneous ESA injection, we conducted a single-blind clinical trial comprising autologous blood donors. Two ESAs were administered 405 times to a total of 203 patients. Both the Visual Analogue Scale (VAS) and the Faces Scale (FS) were used to measure perception of pain after ESA injection. The median VAS score was significantly lower in the epoetin β (EPOβ) group than in the epoetin α (EPOα) group, although a significant difference between groups was not seen on the FS. Multiple regression analysis for the VAS at first injection revealed that both ESA and sex were statistically significant factors for pain. Intriguingly, when the VAS score was compared among four groups that had been divided by sex and ESA preparation, the VAS score of females injected with EPOα was significantly higher than that of the other three groups. EPOα causes more severe pain than EPOβ, especially in females, although this difference in pain does not affect blood collection.