Explanatory Variables as Evidence for Precision in Intramuscular Long-Acting Injections of Patients with Schizophrenia

Intramuscular injections can cause damage to arteries, veins and nerves. Achieving maximum effects of medications through precise intramuscular (IM) injections must be assured and with certainty, particularly with long-acting injection drugs (LAI). The purpose of this study is to determine precision in IM LAIs of patients with schizophrenia. These evidences estimate “Distance from the Epidermis to the Under-Fascia” (DEUF) and “Distance from Epidermis to the Upper-Arm Bone” (DEB) of the deltoid muscle. Explanatory variables include body height, weight, body-mass index (BMI), deltoid-muscle circumference, fat percentage and muscle mass measured by body composition monitor. Sixty nine subjects are included based on the Diagnostic Statistical Manual of Mental Disorders (DSM-IV, 1994), and receive treatments of typical and atypical antipsychotic LAI. There are 46 males and 23 females with average age of 51.41 (Standard Deviation = 13.58) and ranging from 21 to 81 years who are all right-handed. Ultrasonographic data and those from explanatory variables are calculated using Spearman’s rank correlation coefficients. Multiple regression analysis (step-wise method/forced input method) is performed assuming DEUF or DEB as dependent variables. Significant correlations are found with highest adjusted R-square. Paired t-tests show differences in average values of actual ultrasonographic measurements assigned to DEUF or DEB, and the regression equations for accuracy. Ultrasonographic values are assigned multiple-regression equations as true values, and the calculated values are compared with those obtained by regression equations. There are no significant differences observed for either the right or left arm. The multiple regression equations for BMI and fat percentages (upper extremity estimation) of DEUF, and for BMI and injection site circumference of estimated DEB, successfully value the DEUF and DEB. By using these multiple regression equations for IM injection to the deltoid-muscle, DEUF can better ensure accurate LAI into the muscle through body monitor, DEB, and measured values of the deltoid-muscle injection site circumference.

The relationship between body mass index, thickness of subcutaneous fat, and the gluteus muscle as the intramuscular injection site

An intramuscular injection (IMI) is an injection given directly into the central area of a specific muscle. Certain medicines need to be administered by the gluteal route for these to be effective. The aim of this study was to determine the influence of body mass index (BMI), subcutaneous fat, and muscular thickness of the dorsogluteal IMI site among healthy Japanese women. There were 39 healthy female subjects who volunteered and met the criteria. Their ages ranged from 40s to 60s (50.82 ± 6.04). With the data collected using the B-mode ultrasound images of the dorsogluteal site, it was found that the distance from the epidermis to the under-fascia (DEUF) of the gluteus maximus was dissimilar between the subject’s right and left buttocks. It was found that the distance from the epidermis to the iliac bone (DEI) was significantly more on the right than on the left buttocks. In the case of an adult Japanese woman with a BMI of 21 or more, the DEUF of the gluteus medius was found to be about 30 mm, and the DEI was approximately 50 mm or more. Based on these findings, it is recommended that a needle length of 38 mm (1.5 inches) can be safely used to administer IMIs to the gluteus medius muscle to effectively and efficiently deliver medications through the IMI route.

Optimal needle insertion length for intramuscular injection of risperidone long-acting injectable (RLAI)

Risperidone long-acting injectable (RLAI) is approved for the treatment of schizophrenia in many countries. The suggested site is the gluteal muscle with a needle length of two inches (50 mm) in Japan, which is longer than the ordinarily used needle for intramuscular injections. The aim of this study was to determine the optimal needle insertion length for accurate delivery of RLAI procedure among subjects who have normal body mass index (BMI: 18 to 25) and high BMI (>25). Thirty-seven patients with schizophrenia were administered RLAI intramuscularly into the dorsogluteal muscle. The standard procedure required inserting 80% of the two inch needle. By using data collected by ultrasonography, the findings confirmed that the median needle insertion lengths for subjects with normal and high BMI were 39.0 and 45.5 mm, respectively. To deliver RLAI effectively and safely, the authors strongly recommend that a specialized needle be used that is “marked” at the 40 mm point from the tip of the needle to the base. In this way regardless of subcutaneous fat content, the RLAI can be safely delivered into the muscle without causing untoward or side effects.

The Effect of a Psycho-Educational Program on Psychiatric Symptoms, Drug Attitude and Treatment Satisfaction of Patients with Schizophrenia

The purpose of this study was to determine the effect of a Comprehensive Psycho-Educational Approach and Scheme Set (COMPASS) for patients with schizophrenia who were treated with risperidone long-acting injectable (RLAI), on their psychiatric symptoms, drug attitudes, and treatment satisfaction levels. Participants were sixty-five patients at thirteen hospitals in Japan who met ICD-10 F2 criteria for schizophrenia or schizo-affective disorder and were treated with RLAI. A correlational study design was used to measure the effect of the COMPASS on the psychiatric symptoms, drug attitudes, and treatment satisfaction levels of patients treated with RLAI. Using the following evaluation indicators: The Subjective Satisfaction to Treatment Scale (SSTS), Brief Psychiatric Rating Scale (BPRS), Global Assessment of Functioning (GAF), Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS), and Drug Attitude Inventory-10 (DAI-10), measurements were taken at the beginning of the program (baseline), at the end of the program, and six months after (endpoint). Data analysis included descriptive statistics, Mann-Whitney U test or Wilcoxon signed-rank test, and Spearman’s rank correlation coefficient. Significant differences were observed in BPRS total (p < 0.001), sub-scales of BPRS positive (p < 0.001), BPRS negative (p < 0.01), BPRS affective (p < 0.01), and GAF (p < 0.001). However, there was no significant change in subscale of BPRS manic, DAI-10, DIEPSS, or SSTS but significant positive correlations were found between SSTS and DAI-10 and GAF at baseline;a negative correlation was found between SSTS and BPRS. The findings of the study suggested the benefit of using the COMPASS in conjunction with RLAI to decrease patients’ psychiatric symptomatology and improve treatment satisfaction. In addition, patient satisfaction was found to be an important factor to be considered by the psychiatrist.