From the Research
Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is primarily caused by central nervous system disorders, malignancies, pulmonary diseases, and certain medications, as evidenced by the most recent study 1. The causes of SIADH can be categorized into several groups, including:
- Central nervous system disorders such as head trauma, brain tumors, meningitis, encephalitis, and stroke
- Pulmonary disorders like pneumonia, tuberculosis, lung abscess, and small cell lung cancer
- Various malignancies, particularly small cell lung carcinoma, pancreatic cancer, and lymphomas, which can produce ADH ectopically
- Medications that stimulate ADH release or enhance its effects, including antidepressants (SSRIs, TCAs), antipsychotics, anticonvulsants (carbamazepine), chemotherapeutic agents (cyclophosphamide, vincristine), and opioids
- Other causes such as HIV infection, acute intermittent porphyria, and postoperative states, particularly following pituitary surgery, as reported in earlier studies 2, 3, 4, 5 The excessive ADH causes increased water reabsorption in the kidneys, leading to dilutional hyponatremia, concentrated urine despite low serum osmolality, and euvolemic state. Identifying and addressing the underlying cause is essential for effective management of SIADH, as highlighted in the most recent study 1.