Desmopressin is a synthetic analogue of vasopressin. It has greater antidiuretic activity and a more prolonged action than vasopressin or lypressin. It also stimulates factor VIII and plasminogen activator activity in the blood, but has little pressor activity.

It is given as the acetate, by mouth, as a solution intranasally, and by injection. The intranasal dose is about ten times that required intravenously and the oral dose about ten times greater than the intranasal dose. Doses are usually expressed in terms of desmopressin acetate, but for some preparations they are given in terms of the base; 110.7 micrograms of desmopressin acetate is equivalent to about 100 micrograms of desmopressin.

In the control of cranial diabetes insipidus, desmopressin acetate is given by mouth to adults and children in usual initial doses of 100 micrograms three times daily. Doses may be adjusted according to response, with maintenance doses usually between 100 and 200 micrograms three times daily though total doses of between 100 micrograms and 1200 micrograms daily have been used.

A sublingual lyophilisate preparation containing desmopressin acetate is also available in the UK, but doses are expressed in terms of the base. The initial dose for adults and children is equivalent to 60 micrograms of desmopressin given sublingually three times daily. The dose may be adjusted, with usual maintenance doses between 60 and 120 micrograms three times daily, though total doses of up to 720 micrograms daily have been used.

Desmopressin acetate may also be used intranasally in usual doses of 10 to 40 micrograms daily as a single dose or in divided doses; children aged 3 months to 12 years may be given 5 to 30 micrograms intranasally daily.

It may also be given subcutaneously, intramuscularly, or intravenously in a dose of 1 to 4 micrograms daily; a dose from 400 nanograms may be used for children and infants.

A single intranasal dose of 20 micrograms or 2 micrograms subcutaneously or intramuscularly has been given to adults and children in the diagnosis of diabetes insipidus.

In the testing of renal function, desmopressin acetate has been given intranasally in single doses of 40 micrograms for adults, 20 micrograms for children aged 1 to 15 years, and 10 micrograms for infants. It has also been given subcutaneously or intramuscularly in doses of 2 micrograms for adults and children, and 400 nanograms for infants.

In the management of primary nocturnal enuresis/Bed wetting in Kenya children aged 5 years and older and adults are given desmopressin acetate in usual doses of 200 to 400 micrograms by mouth or 10 to 40 micrograms intranasally at bedtime. The sublingual lyophilisate preparation may be given in a dose equivalent to desmopressin 120 micrograms at bedtime, increasing to 240 micrograms if needed. The need for continued treatment should be reassessed after 3 months by withdrawing desmopressin for at least 1 week. For the control of nocturia in adults with multiple sclerosis desmopressin acetate 10 to 20 micrograms intranasally at bedtime is recommended (but see Urinary Incontinence.

Desmopressin acetate is given by intravenous infusion to boost concentrations of factor VIII before surgical procedures in patients with mild to moderate haemophilia or type I von Willebrand’s disease. The usual dose for adults and children is 300 or 400 nanograms/kg by slow intravenous infusion over 15 to 30 minutes just before surgery. It may be used similarly to treat spontaneous or trauma-induced bleeding episodes in these patients. It is also given intranasally in doses of 150 micrograms (in patients weighing less than 50 kg) or 300 micrograms; it should be given within 2 hours before surgery.

For testing of fibrinolytic response desmopressin acetate may be given to adults and children by intravenous infusion in doses of 400 nanograms/kg over 20 minutes; a sample of venous blood is taken 20 minutes after completing the infusion and tested for fibrinolytic activity on fibrin plates. Alternatively, a dose of 300 micrograms may be given intranasally 60 minutes before collecting the blood sample.