Since ICPI can cause thyroiditis and adrenal insufficiency, the TSH and AM cortisol should be checked -- in addition to the usual evaluation for hyponatremia (serum and urine Osm, urine electrolytes, and an assessment of the patient's volume status). If adrenal insufficiency is present, the hyponatr...

Immune checkpoint inhibitors (here nivolumab) have been associated with hyponatremia. The most common is still SIADH based on a single-center study. Endocrinopathies, as mentioned above, are definitely in the differential and need to be ruled out as treatment is usually steroids and can really help....