Hypotonic hyponatremia Hypotonic hyponatremia Hypoosmolar hyponatremia is a condition where hyponatremia associated with a low plasma osmolality. The term "hypotonic hyponatremia" is also sometimes used. When the plasma osmolarity is low, the extracellular fluid volume status may be in one of three states: low volume, normal volume, or high volume. Loss of water is accompanied by loss of sodium. Treat underlying cause and give IV isotonic saline. It is important to note that sudden restoration of blood volume to normal will turn off the stimulus for continued ADH secretion. Hence, a prompt water diuresis will occur. This can cause a sudden and
Hypotonic hyponatremia a side effect of certain medicines, lung problems such as pneumonia or abscess, brain disease, or certain cancers (most often small cell lung carcinoma). The cornerstone of therapy for SIADH is reduction of water intake. If hyponatremia persists, then demeclocycline (an antibiotic with the side effect of inhibiting ADH) can be used. SIADH can also be treated with specific antagonists of the ADH receptors, such as conivaptan or tolvaptan. Another cause is psychogenic polydipsia. A third group of people with hyponatremia are often said to be "hypervolemic". They are identified by the presence of peripheral edema. In fact, the term