Lemborexant, an orexin receptor antagonist (ORA), was introduced as a safer sleep medication at our hospital, but its prescription rate remained low. To address this issue, promotion of ORAs began in August 2022. This study aimed to evaluate the impact of these activities on the number of patients prescribed lemborexant. And it aimed to evaluate prescription conditions non-benzodiazepine drugs (NBDs) and delirium treatment antipsychotics (DTAs). The study spanned from August 2021 to March 2024, with August 2022 serving as the intervention point. The drugs analyzed included lemborexant, zolpidem and eszopiclone (NBDs), and risperidone and quetiapine (DTAs). Analyzed using interrupted time-series analysis, and assess changes in the number of patients prescribed these medications and the number of patients with abnormal indications. The promotion of ORAs significantly increased lemborexant prescriptions [level change 18 (95% confidence interval 0.07 to 35: p=0.049), slope change 2.7 (0.57 to 4.9: p=0.015)]. Concurrently, prescriptions for NBDs decreased [level change −56 (−86 to −25: p<0.001), slope change −30 (−54 to −5.7: p=0.017)], and the slope change for DTAs with abnormal instructions also decreased [−1.2 (−2.3 to −0.11: p=0.032)]. No significant differences were found for the other items. Promoting ORAs increased its use, and led to a reduction in the prescriptions of NBDs and DTAs with abnormal indications. Although there was no change in patient conditions, given the adverse effects associated with NBDs and DTAs these changes suggest a shift toward safer drug treatment practices.