A retrospective comparison of haloperidol and hydroxyzine combination therapy with haloperidol alone in the treatment of overactive delirium

Background For the treatment of delirium, antipsychotics such as haloperidol are used as standard treatments. However, haloperidol has a little sedative effect and may not be sufficiently effective in controlling overactive delirium. Hydroxyzine, an antihistamine, may be used in combination with haloperidol to supplement its sedative effect. The aim of this study was to investigate the effect of haloperidol alone or in combination with hydroxyzine on the improvement of overactive delirium retrospectively. Method Delirium was assessed from medical records using the Intensive Care Delirium Screening Checklist (ICDSC). The number of patients and days with an ICDSC score of <4, indicating an absence of delirium after haloperidol alone or haloperidol and hydroxyzine was surveyed for 6 days. Results A total of 157 patients were diagnosed with delirium from April 2019 to July 2021, of which 18 patients received haloperidol alone, and 21 patients received the combination of haloperidol and hydroxyzine for overactive delirium. The number of patients with a mean ICDSC score of <4 on days 1-6 was two patients (11%) in the haloperidol groups and two patients (10%) in the combination of haloperidol and hydroxyzine group (P = 0.999). The days within < 4 of the ICDSC score on days 1-6 were 0.8 (1.3) and 0.8 (1.5), respectively (P = 0.848). Conclusion Haloperidol alone and haloperidol plus hydroxyzine are both effective in the treatment of overactive delirium. However, the concomitant use of hydroxyzine with haloperidol may not improve the efficacy of treatment of overactive delirium compared to haloperidol alone.