Objective: To identify factors affecting adherence to medication, a subjective questionnaire survey was administered to schizophrenia patients regarding the prescribed antipsychotic formulations. Methods: We evaluated the patients’ satisfaction and dissatisfaction with prescribed antipsychotic formulations, and patients answered the Drug Attitude Inventory-10 Questionnaire (DAI-10). Inclusion criteria for patients are as follows:age between 20 and 75 years and taking antipsychotic agents containing the same ingredients and formulations, for at least 1 month. Results: In total, 301 patients answered the questionnaire survey. Tablets were found to be the most commonly used antipsychotic formulations among schizophrenia patients (n = 174, 57.8%), followed by long-acting injections (LAIs, n = 93, 30.9%). No significant differences in the formulation satisfaction level and DAI-10 scores were observed between all formulations. Formulations, except for LAI, were selected by physicians in more than half of the patients.Patients who answered “Decided by consultation with physicians” had significantly higher satisfaction levels and DAI-10 scores compared to those who answered “Decided by physicians” (4.11 ± 0.77 vs. 3.80 ± 1.00, p = 0.0073 and 6.20 ± 3.51 vs. 4.39 ± 4.56, p ＜ 0.001, respectively). Satisfaction levels moderately correlated with DAI-10 scores (r = 0.48, p ＜ 0.001). Conclusion No formulation had a high satisfaction level in all patients, and it is important to be reflect the patients’ individual preferences in pharmacotherapy. Shared decision-making in the selection of the formulations is seen to be useful for improving medication adherence.

Objective: To improve poor medication adherence in schizophrenic patients, long-acting injectable (LAI) antipsychotics are used. However, it has not yet become common in Japan. Recently, aripiprazole LAI was approved for alternative injection into the deltoid muscle in addition to the gluteal muscle. The acceptance for the proposal to switch from gluteal to deltoid injections of aripiprazole LAI was investigated. Methods: The subjects were 32 outpatients with schizophrenia who had continuously received aripiprazole LAI administration into the gluteal muscle for ≥ 6 months. In the patients who had continued deltoid injection for 3 months after switching, the changes in the pain and shame in comparison with gluteal injections were evaluated. Results: Switching to the deltoid injection was chosen by 17 out of 32 patients. Three months later, 9 patients were still receiving deltoid injections with highly rated satisfaction. The main reasons for switching to deltoid injections included the pain and shame associated with gluteal injections. The main reason for returning to the gluteal injection was the pain experienced from the injection in the deltoid. Conclusion The option to select the injected area was based on the amount of pain in the deltoid and gluteal sites, leading to the widespread use of aripiprazole LAI.