Takenaka Ryo, Emori Kayo, Kawashima Hirotsugu
Department of Psychiatry Toyooka Public Hospital Toyooka Japan.
Department of Pharmacy Ainohanazono Hospital Ibaraki City Japan.
PCN Rep. 2025 Jul 16;4(3):e70155. doi: 10.1002/pcn5.70155. eCollection 2025 Sep.
An association between constipation and psychiatric disorders has been suggested. While magnesium oxide (MgO) is frequently administered in Japan to treat constipation, there is a risk of developing hypermagnesemia. We aimed to investigate the characteristics of hypermagnesemia in patients admitted to psychiatric hospitals.
Among all patients admitted to Ainohanazono Hospital between January 2020 and December 2023 who had undergone ≥1 blood test, we retrospectively investigated the risk of developing hypermagnesemia in those with or without MgO, patient characteristics associated with this risk, and characteristics that determined the MgO dosage.
Of 1120 patients, 532 (48%) were prescribed MgO. The risk of developing hypermagnesemia was 2.76 times higher for patients prescribed MgO than for those not prescribed MgO. Patient characteristics associated with the risk of developing hypermagnesemia were daily MgO dose (hazards ratio [HR] 2.66), serum creatinine level (HR 1.75), and female biological sex (HR 1.44). Regarding patient characteristics that determined the prescribed MgO dosage, concomitantly administered antipsychotic and anticholinergic drugs were associated with an increase in the amount prescribed (odds ratio [OR] 1.12 and OR 1.06, respectively). However, long-term treatment duration (OR 0.91) and blood urea nitrogen levels (OR 0.95) were associated with a decrease in the dosage.
We clarified the risk of MgO-related hypermagnesemia, particularly for patients undergoing long-term (>1 year) MgO administration. Antipsychotic and anticholinergic drug dosages slightly affected the increase in the MgO dosage. Regular blood sampling is needed to prevent hypermagnesemia, with a switch to a non-MgO laxative when renal function is impaired.
已有研究表明便秘与精神障碍之间存在关联。在日本，氧化镁（MgO）常用于治疗便秘，但存在发生高镁血症的风险。我们旨在调查精神科住院患者高镁血症的特征。
在2020年1月至2023年12月期间入住相之原医院且接受过≥1次血液检查的所有患者中，我们回顾性调查了使用或未使用MgO的患者发生高镁血症的风险、与此风险相关的患者特征以及决定MgO剂量的特征。
在1120例患者中，532例（48%）使用了MgO。使用MgO的患者发生高镁血症的风险比未使用MgO的患者高2.76倍。与发生高镁血症风险相关的患者特征包括每日MgO剂量（风险比[HR] 2.66）、血清肌酐水平（HR 1.75）和女性生理性别（HR 1.44）。关于决定MgO处方剂量的患者特征，同时使用的抗精神病药物和抗胆碱能药物与处方剂量增加相关（优势比[OR]分别为1.12和1.06）。然而，长期治疗时间（OR 0.91）和血尿素氮水平（OR 0.95）与剂量减少相关。
我们明确了MgO相关高镁血症的风险，特别是对于长期（>1年）使用MgO的患者。抗精神病药物和抗胆碱能药物的剂量对MgO剂量的增加有轻微影响。需要定期采血以预防高镁血症，当肾功能受损时应改用非MgO泻药。
