The administration of an intramuscular injection (IMI) is a basic nursing skill, primarily involving the gluteus and deltoid muscles. Nurses must determine the appropriate needle type, gauge, and depth of insertion for giving an IMI while avoiding injury to blood vessels and nerves. The primary purposes of this study were to determine the appropriate depth of injection for administering risperidone long-acting injectable (RLAI) and to evaluate the injected drug absorption using B-mode ultrasonography. In this study, the subjects were three patients with schizophrenia being treated with RLAI. The IMI procedures were monitored using B-mode ultrasonography during the injection of RLAI. One patient received an adequate injection in the gluteus medius muscle; however, the other two patients received inadequately positioned injections. Ultrasonography was useful for checking the absorption progress of the RLAI-loaded microspheres.
