[An experimental study of the tissue reactions in rats induced by different concentrations of benzathine penicillin G].

The search of scientific answers to problems due to procedures involving professional actions is a permanent challenge to the nurses committed with the improving of nursing care. In face of the intensive muscle soreness provoked by penicillin G benzatin shots, an experimental evaluation of this procedure was carried out in order to observe the influences of concentration and volumes used. This evaluation could give some insights to improve the nursing care, particularly those linked to the manipulation of the penicillin injection. The study was performed in the Faculty of Medicine of the University of São Paulo, in 27 Male Wistar rats. After the injection of the drug or saline solution in the right and left limb, respectively, the animals were sacrificed and the muscles in which the solution were injected were histologically examined. The use of penicillin provoked intensive inflammatory reaction, the peak intensity being attained after 48 hours. A remaining effect lasted about thirty days. The inflammatory reaction was similar for the three concentrations of penicillin. Nevertheless, the present research does not bring data that should modify the current injection procedures.