Experimental evaluation of hyaluronidase activity in combination with specific drugs applied in clinical techniques of interventional pain management and local anaesthesia.

BACKGROUND Hyaluronidase is an enzyme additive used in local anaesthesia and interventional pain reducing procedures such as adhesiolysis of epidural scar tissue after spinal surgery. Only a limited number of studies describe the influence of drugs on hyaluronidase activity. Postulated effects and effectiveness of hyaluronidase are only based on clinical observations. OBJECTIVE The aim of this study is to investigate the influence of the combined drugs on the activity of hyaluronidase under standardized conditions and to verify the effectiveness of the enzyme. DESIGN An ELISA-based microtiter-technique is used to evaluate the activity of hyaluronidase in combination with local anaesthetics, corticosteroids, NaCl 10%, and iodinated contrast media. METHODS Microtiter plates were coated with biotinylated hyaluronate and incubated with hyaluronidase in combination with the above-mentioned drugs. The activity of hyaluronidase was determined by an avidin-peroxidase-based procedure using an ELISA reader. Incubations were carried out at room temperature as well as at 37 degrees C. RESULTS The data show that drugs affect the activity of hyaluronidase in different ways. Iodinated contrast media, NaCl (10%), and the absence of corticosteroids reduce hyaluronidase activity. In contrast, higher activities were detected at a lower NaCl concentration (0.9%). We cannot attribute a significant influence to local anaesthetics. CONCLUSIONS Hyaluronidase is effective in all combinations with drugs. To get the maximum effect calculated use of accompanying drugs is necessary.