Desmopressin

How it works

It acts on renal vasopressin (V2) receptors to promote water reabsorption, and stimulates release of factor VIII and von Willebrand factor from endothelial stores, briefly improving haemostasis.

Prescribing in practice

• Hyponatraemia from water retention is the key hazard and can cause seizures, so fluid restriction and sodium monitoring around dosing are essential.
• Use with caution where fluid overload is a concern, including cardiac or renal impairment, and in older people who are more susceptible to water intoxication.
• Effectiveness in raising clotting factors diminishes with repeated doses (tachyphylaxis), limiting its use over consecutive days for haemostatic indications.

Monitoring

Monitor serum sodium and fluid balance, especially at initiation and when the indication carries a high water-retention risk; for haemostatic use assess factor VIII or von Willebrand factor response and clinical bleeding.

Counselling the patient

• Follow the fluid-restriction advice given, and report headache, nausea, drowsiness or confusion, which may signal low sodium.
• Seek urgent help if a seizure or marked drowsiness occurs.
• For bedwetting, avoid drinking large amounts of fluid in the evening as advised.

Evidence & guidelines

A standard treatment for cranial diabetes insipidus and a recognised option in nocturnal enuresis and in mild haemophilia A and von Willebrand disease.