Spigset O, Hedenmalm K
Division of Clinical Pharmacology, Norrland University Hospital, Umeå, Sweden.
Drug Saf. 1995 Mar;12(3):209-25. doi: 10.2165/00002018-199512030-00006.
The use of psychotropic drugs has been associated with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in a number of case reports. SIADH is characterised by the sustained release of antidiuretic hormone (ADH) from the posterior pituitary. The patients have a reduced ability to excrete diluted urine, ingested fluid is retained, and the extracellular fluid expands and becomes hypo-osmolar. The cardinal signs are hyponatraemia, serum hypoosmolality and a less than maximally diluted urine. Common symptoms include weakness, lethargy, headache, anorexia and weight gain. These symptoms may be followed by confusion, convulsions, coma and death. The early symptoms are vague and nonspecific, and they may even mimic the symptoms of the psychiatric disorder itself. For antidepressants, the risk of SIADH seems to be highest during the first weeks of treatment. For antipsychotics, the risk seems to be more spread out in time. The causative role of the drug may sometimes be difficult to estimate, as even drug-free psychiatric patients, mostly those with schizophrenia, develop SIADH on the basis of psychogenic polydipsia. Smoking is another factor associated with the development of SIADH, and the risk may also increase with age. The acute treatment of SIADH induced by a psychotropic drug includes discontinuation of the drug as well as restriction of fluid intake. In cases with significant clinical symptoms, infusion of sodium chloride is recommended. After the acute management, it is useful to evaluate the causative role of the drug by performing a water loading test and/or drug rechallenge. If continued treatment with an antidepressant or antipsychotic is indicated, a drug with a different pharmacological profile should be chosen, and the serum sodium levels should be monitored closely. If treatment with the drug that caused SIADH must be continued, concomitant treatment with demeclocycline may reduce the tendency of hyponatraemia.
在一些病例报告中，使用精神药物与抗利尿激素分泌不当综合征（SIADH）有关。SIADH的特征是垂体后叶持续释放抗利尿激素（ADH）。患者排泄稀释尿液的能力降低，摄入的液体潴留，细胞外液扩张并变为低渗状态。主要体征为低钠血症、血清低渗以及尿液稀释不完全。常见症状包括虚弱、嗜睡、头痛、厌食和体重增加。这些症状之后可能会出现意识模糊、惊厥、昏迷甚至死亡。早期症状模糊且不具特异性，甚至可能与精神障碍本身的症状相似。对于抗抑郁药，SIADH的风险似乎在治疗的最初几周最高。对于抗精神病药，风险在时间上似乎分布更分散。药物的致病作用有时可能难以评估，因为即使是未服用药物的精神病患者，主要是精神分裂症患者，也会因精神性多饮而发生SIADH。吸烟是与SIADH发生相关的另一个因素，风险也可能随年龄增加。由精神药物引起的SIADH的急性治疗包括停用药物以及限制液体摄入。对于有明显临床症状的病例，建议输注氯化钠。急性处理后，通过进行水负荷试验和/或药物再激发来评估药物的致病作用是有用的。如果需要继续使用抗抑郁药或抗精神病药治疗，应选择具有不同药理特性的药物，并密切监测血清钠水平。如果必须继续使用导致SIADH的药物治疗，同时使用地美环素可能会降低低钠血症的倾向。
