長谷川 直

STUDY OBJECTIVES: Although novel hypnotics have recently emerged, there are currently no data comparing the clinical potency of benzodiazepine receptor agonists (BZRAs) and novel hypnotics, or the effectiveness of different methods of switching between them. This study examined how novel hypnotics might help reduce BZRA use in real-world practice. METHODS: 289 patients with psychiatric disorders who took BZRAs for over 1 year before switching to either of two dual-orexin receptor antagonists (DORAs) (suvorexant (SUV) or lemborexant (LEM)) or a melatonin receptor agonist (ramelteon (RMT)) were enrolled. We collected data on BZRAs at baseline and 3 months after commencement of SUV/LEM/RMT. RESULTS: Significant reductions in BZRAs were observed for all three agents: -4.10, -2.80 and -1.65 mg in diazepam-equivalent dose in the SUV, LEM and RMT groups, respectively. Dose reduction was significantly greater in the DORA than the RMT group (F=15.053, P<0.001). Within the DORA group, dose reduction was significantly greater in patients taking SUV than those taking LEM (F=4.337, P=0.043). The switching success rate did not differ among the switching methods for any of the hypnotics. CONCLUSIONS: The reduction rate of BZRAs achieved by the switch fell into their equivalent-potency range estimated from clinical trials. The results suggest that DORAs can replace approximately one tablet of a BZRA. The difference in dose reduction between DORAs and RMT reflected the greater sleeping potency of the DORAs, whereas that between SUV and LEM might have reflected patient backgrounds: patients taking LEM may have been more strongly dependent on BZRAs.

Although many screening tools for delirium are available, delirium is still occasionally overlooked or misdiagnosed. One of the reasons for this is the lack of brief screening tools that do not require specialized training to use. The 4 'A's test (the 4AT) is a validated screening tool for delirium that can be administered in a very short time without specialized training. Herein, we evaluated the reliability and validity of the Japanese version of the 4AT (the 4AT-J). A total of 150 patients aged ≥ 65 years were enrolled. Their demographics and clinical characteristics were obtained within 24 hr of their hospitalization. On each patient's high-risk day of developing delirium, the 4AT-J was administered by a nurse, and the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-Ⅴ) and the Japanese version of Delirium Rating Scale-Revised-98 (DRS-98-J) were administered by a psychiatrist. Our analyses revealed that when a cut-off score of 4, the 4AT-J showed high sensitivity and specificity. The Cronbach's α-coefficient was similar to that of the original version. A receiver operating curve analysis showed sufficient power of the 4AT-J to discriminate delirium. The 4AT-J showed adequate reliability and validity for delirium screening in elderly patients.