ANALYSIS OF THE EFFICACY OF MEASURES TO REDUCE PAIN AFTER SUBCUTANEOUS ADMINISTRATION OF EPOETIN ALFA

Pain at the injection site with subcutaneous administration of epoetin alfa preparations is a common adverse event, and sometimes precludes self-administration. The pain is caused mainly by the vehicle. The pre sent studies were designed to assess whether pain after subcutaneous a dministration of the vehicle can be influenced by making the solution isoosmotic, or by diluting the vehicle by the bacteriostatic agent ben zyl alcohol saline (BAS). The volumes injected were 1 ml. We also dete rmined whether reduction of the injected volume of 1 ml to 0.33 ml or to 0.1 ml could be of clinical importance. One millilitre of normal sa line served as a placebo control. The studies were done in a double-bl ind, placebo-controlled, randomized order, cross-over fashion in healt hy volunteers. Pain scores were obtained from visual analogue pain sca les with no divisions and from 5-point verbal descriptive pain scales. Dilution of the vehicle with BAS resulted in significantly less pain (P < 0.0001) after subcutaneous injection, comparable to levels obtain ed with normal saline. Making the vehicle iso-osmotic had no effects. Injection of smaller volumes of the vehicle was beneficial with 0.1 ml (P < 0.0001), but the reduction to 0.33 ml was not statistically sign ificant.