Side by side

1. 1.Activates V2 receptors on the collecting ducts of the kidney, inserting aquaporin-2 channels and reabsorbing water without sodium.
2. 2.Releases von Willebrand factor and factor VIII from endothelial storage pools.
3. 3.Has little V1 activity, so it does not raise blood pressure the way natural vasopressin does.
4. 4.Concentrates urine within about an hour of an effective dose.
5. 5.Supports platelet function in some inherited disorders.

• Central (cranial) diabetes insipidus
• Nocturnal enuresis in children
• Mild haemophilia A and type 1 von Willebrand disease
• Platelet function disorders before procedures
• Diagnostic urine concentration testing

• Rapid fall in urine volume and rise in urine osmolality in central diabetes insipidus
• Two- to four-fold rise in factor VIII and von Willebrand factor in responsive patients
• Fewer night-time wettings in enuresis trials
• Hyponatraemia when fluid intake is not restricted

• Hyponatraemia and water intoxication, which can cause headache, nausea, confusion and seizures
• Fluid retention and peripheral oedema
• Facial flushing and headache
• Nasal irritation and rhinitis with the spray
• Abdominal cramps
• Rare allergic reactions

Research context only - prescription medicine. Dosing differs sharply between indications and between tablets, nasal spray and injection, for example 0.1 to 0.2 mg tablets in adults for diabetes insipidus versus weight-based intravenous dosing for haemostasis. Hyponatraemia risk depends on dose, fluid intake and age, and needs monitoring. Nothing here is a dosing suggestion.

Research context only