From the Guidelines
Diabetes insipidus is a rare disorder characterized by insensitivity of the distal nephron to antidiuretic hormone (ADH), leading to polyuria, polydipsia, and the risk of hypertonic dehydration, as noted in a recent expert consensus statement 1. This condition occurs in two main forms: central diabetes insipidus, where the brain doesn't produce enough ADH, and nephrogenic diabetes insipidus, where the kidneys don't respond properly to ADH.
- Key characteristics of diabetes insipidus include:
- Polyuria, with urine output often exceeding 3 liters per day
- Polydipsia, or excessive thirst
- Failure to thrive and signs of dehydration in infants
- Serum osmolality usually >300 mOsm/kg H2O owing to hypernatraemia, whereas urine is inappropriately diluted, with osmolality usually <200 mOsm/kg H2O, as reported in a study published in Nature Reviews Nephrology 1
- Diagnosis of diabetes insipidus typically involves:
- Water deprivation tests
- Measuring blood sodium levels
- Sometimes MRI imaging of the brain
- Treatment for central diabetes insipidus usually involves desmopressin (DDAVP), which replaces the missing hormone, while nephrogenic diabetes insipidus may be managed with thiazide diuretics, a low-salt diet, and NSAIDs like indomethacin, as suggested by recent clinical practice recommendations 1. The most effective treatment approach should prioritize reducing urine output and managing symptoms to prevent dehydration, electrolyte imbalances, and potential neurological damage from hypernatremia, as emphasized in the latest expert consensus statement 1.
From the FDA Drug Label
Desmopressin Acetate Injection is indicated as antidiuretic replacement therapy in the management of central (cranial) diabetes insipidus and for the management of the temporary polyuria and polydipsia following head trauma or surgery in the pituitary region
- Central Diabetes Insipidus is a condition that is managed with desmopressin acetate injection.
- The drug label does not provide a definition of Diabetes Insipidus itself, but it mentions that desmopressin acetate injection is used to manage central (cranial) diabetes insipidus.
- It is also mentioned that desmopressin acetate injection is ineffective and not indicated for the treatment of nephrogenic diabetes insipidus 2.
- Based on the information provided in the drug label, Diabetes Insipidus can be inferred to be a condition characterized by polyuria and polydipsia, which can be managed with desmopressin acetate injection in the case of central diabetes insipidus 2.
From the Research
Definition and Classification of Diabetes Insipidus
- Diabetes insipidus (DI) is an endocrine condition involving the posterior pituitary peptide hormone, antidiuretic hormone (ADH) 3.
- It is characterized by expelling excessive quantities of highly dilute urine, extreme thirst, and craving for cold water 3.
- The two main classifications of DI are central diabetes insipidus (CDI), characterized by a deficiency of the posterior pituitary gland to release ADH, and nephrogenic diabetes insipidus (NDI), characterized by the terminal distal convoluted tubule and collecting duct resistance to ADH 3.
- Two less common classifications include dipsogenic DI, characterized by excessive thirst due to a low osmotic threshold, and gestational DI, characterized by increased concentration of placental vasopressinase during pregnancy 3.
Pathophysiology and Diagnosis
- DI is marked by the inability to respond to or produce ADH, leading to the inability of the kidneys to reabsorb water, resulting in hypotonic polyuria and, if lack of hydration, hypernatremia 4.
- The gold standard for diagnosis is a water deprivation test followed by desmopressin administration 4.
- A new surrogate marker of ADH called copeptin may simplify and improve the accuracy in diagnosing DI in the future 4.
- Functional tests such as water deprivation or stimulation of copeptin by hyperosmolarity can be proposed to distinguish between different etiologies 5.
Treatment and Management
- Treatment of DI is dependent on the disease classification, but severe complications may arise if not tended to appropriately 3.
- The most common treatment of CDI and gestational DI is the administration of synthetic ADH, desmopressin (DDAVP) 3, 6.
- Nephrogenic treatment requires discontinuation of medications as well as maintaining a renal-friendly diet to prevent hypernatremia 3.
- Treatment of dipsogenic DI is mainly focused on behavioral therapy aimed at regulating water intake and/or administration of antipsychotic pharmaceutical therapy 3.
- Central and nephrogenic subtypes of DI share a paradoxical treatment in thiazide diuretics 3.