From the Guidelines
Diabetes insipidus (DI) is a rare disorder that should be diagnosed and treated based on its type, with central DI typically managed with desmopressin (DDAVP) and nephrogenic DI treated with thiazide diuretics, a low-salt diet, and NSAIDs in some cases, as recommended by the most recent expert consensus statement 1, 2, 3, 4, 5, 6.
Diagnosis of Diabetes Insipidus
The diagnosis of DI involves distinguishing between central and nephrogenic forms, with key characteristics including polyuria, polydipsia, and the risk of hypertonic dehydration. Serum osmolality is usually >300 mOsm/kg H2O, whereas urine is inappropriately diluted, with osmolality usually <200 mOsm/kg H2O 1. Differential diagnoses include acquired NDI, central DI, primary polydipsia, poorly controlled diabetes mellitus, and secondary forms of inherited NDI, among others 4.
Treatment of Central Diabetes Insipidus
For central diabetes insipidus, desmopressin (DDAVP) is the primary medication, available as nasal spray (10-40 mcg daily in 1-3 doses), oral tablets (0.1-0.8 mg daily), or sublingual tablets (60-240 mcg daily) [@Example@].
Treatment of Nephrogenic Diabetes Insipidus
For nephrogenic diabetes insipidus, thiazide diuretics like hydrochlorothiazide (25-50 mg daily) may be prescribed, along with a low-salt diet and NSAIDs like indomethacin in some cases [@Example@]. Additionally, recommendations for treatment and follow-up in children include free access to fluid, normal-for-age milk intake, and considering tube feeding in infants and children with repeated episodes of vomiting and dehydration and/or failure to thrive 5.
Management and Follow-Up
Patients with DI should monitor fluid intake and output, maintain electrolyte balance, and be aware of symptoms of dehydration or water intoxication. Ad libitum access to fluid is recommended to prevent dehydration, hypernatraemia, growth failure, and constipation 6. For patients who cannot self-regulate their fluid intake, water should be offered frequently on top of their regular fluid intake, and close monitoring of weight, fluid balance, and biochemistry is crucial 6.
Key Recommendations
- Free access to fluid in all patients with NDI to prevent dehydration, hypernatraemia, growth failure, and constipation 6.
- Normal-for-age milk intake in infants with NDI to guarantee adequate caloric intake 5.
- Considering tube feeding in infants and children with repeated episodes of vomiting and dehydration and/or failure to thrive 5.
- Dietetic counselling from a dietitian who has experience with the disease 5.
- Monitoring dietary salt and protein intake to reduce renal osmotic load and thereby minimize urine volume 5.
From the FDA Drug Label
1.1 Central Diabetes Insipidus 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 Limitations of Use Desmopressin Acetate Injection is ineffective and not indicated for the treatment of nephrogenic diabetes insipidus.
The diagnosis of Diabetes Insipidus (DI) is not directly stated in the provided drug labels, but the treatment for central DI is described.
- Central Diabetes Insipidus is treated with desmopressin acetate injection as antidiuretic replacement therapy.
- The recommended starting daily dosage for central DI is 2 mcg to 4 mcg administered as one or two divided doses by subcutaneous or intravenous injection.
- Nephrogenic Diabetes Insipidus is not treated with desmopressin acetate injection, as it is ineffective for this condition 7.
From the Research
Diagnosis of Diabetes Insipidus (DI)
- Diabetes insipidus is a disorder characterized by a high hypotonic urinary output of more than 50ml per kg body weight per 24 hours, with associated polydipsia of more than 3 liters a day 8
- The diagnosis of DI must be distinguished from primary polydipsia and other causes of hypotonic polyuria 9
- Differentiation between the various forms of hypotonic polyuria is done by the classical water deprivation test or the more recently developed hypertonic saline or arginine stimulation together with copeptin (or AVP) measurement 10
- A detailed medical history, physical examination, and imaging studies are needed to detect the aetiology of diabetes insipidus 10
Treatment of Diabetes Insipidus (DI)
- Treatment of central DI consists of fluid management and drug therapy with the synthetic AVP analogue Desmopressin (DDAVP) 8
- Desmopressin can be administered subcutaneously, intranasally, or orally, and the patient usually finds the effective minimal dose necessary for a normal life 11
- Patient education is necessary to avoid the risk of water intoxication and hyponatremia 11
- Treatment of nephrogenic DI typically involves thiazide diuretics and nonsteroidal anti-inflammatory drugs (NSAIDs), but desmopressin can also be a viable treatment option 12
- Treatment of diabetes insipidus or primary polydipsia depends on the underlying aetiology and differs in central diabetes insipidus, nephrogenic diabetes insipidus, and primary polydipsia 10
Forms of Diabetes Insipidus (DI)
- Central DI results from inadequate secretion and usually deficient synthesis of Arginine vasopressin (AVP) in the hypothalamus or pituitary gland 8
- Nephrogenic DI results from resistance to AVP in the kidneys 10
- Primary polydipsia involves excessive intake of large amounts of water despite normal AVP secretion and action 10
- Gestational diabetes insipidus results from an increase in placental vasopressinase 10