Desmopressin

At a glance

Category

Hormonal & sexual

Status

approved drug

Route

oral tablet, sublingual melt, intranasal spray, subcutaneous and intravenous injection

Half-life

terminal half-life approximately 2.8 hours after intravenous administration 4; the antidiuretic effect outlasts this and typically persists 6-14 hours depending on dose and route

Onset

antidiuresis within about 1 hour of an oral dose; factor VIII activity peaks between 90 minutes and 2 hours after intravenous infusion, with a haemostatic effect lasting about 8-12 hours 4

Molecular weight

1069.2 g/mol (free base); 1129.3 g/mol as the acetate salt

Sequence

Cyclic nonapeptide: Mpr-Tyr-Phe-Gln-Asn-Cys-Pro-D-Arg-Gly-NH2, with a disulfide bridge between positions 1 and 6. Differs from arginine vasopressin by deamination at position 1 and substitution of L-arginine by D-arginine at position 8.

Mechanism of action

Desmopressin is a selective agonist at the vasopressin V2 receptor with very little activity at V1a receptors. V2 receptors on the principal cells of the renal collecting duct are Gs-coupled: activation raises intracellular cAMP, activates protein kinase A, and drives aquaporin-2 water channels from intracellular vesicles into the apical membrane. Water is then reabsorbed down the medullary osmotic gradient, urine volume falls and urine osmolality rises. Because V1a-mediated vasoconstriction is largely absent, desmopressin produces the antidiuretic effect of vasopressin without a meaningful pressor effect.

The two structural changes explain both the selectivity and the duration of action. Removing the free amino group at position 1 (deamination) makes the molecule resistant to aminopeptidase cleavage, and replacing L-arginine with D-arginine at position 8 both lengthens the half-life and strips away most of the V1a vasopressor activity. The result is roughly 2-4 times the antidiuretic potency of vasopressin with a fraction of its vascular effect.

A separate, dose-dependent haemostatic action underlies its use in bleeding disorders. V2 receptors on vascular endothelium trigger exocytosis of Weibel-Palade bodies, releasing stored von Willebrand factor and, with it, factor VIII. Plasma levels of both typically rise two- to five-fold, enough to cover minor surgery or dental extraction in mild haemophilia A and type 1 von Willebrand disease. The stores are finite, so repeated doses give progressively smaller responses (tachyphylaxis) until the endothelial pool is replenished over one to several days.

The same mechanism that makes desmopressin useful makes it dangerous. Water retention is unopposed by the normal osmotic brake on vasopressin secretion, so if the patient continues to drink freely the extracellular fluid dilutes and serum sodium falls. Hyponatraemia is therefore not an idiosyncratic reaction but a direct, predictable extension of the drug's pharmacology.

What the research shows

The evidence base is mature and largely uncontested for the licensed indications. Desmopressin has been used clinically for around fifty years, its efficacy in central diabetes insipidus is essentially definitional, and randomised trials support its use in nocturnal enuresis, nocturia due to nocturnal polyuria and mild haemostatic defects. The main modern research question is not whether it works but how often it causes hyponatraemia and in whom.

Research in humans

In central (arginine-vasopressin-deficient) diabetes insipidus, desmopressin reliably reduces urine output and restores urine concentrating ability; this is the standard of care and the diagnostic response itself. In primary nocturnal enuresis, randomised trials and systematic reviews show a reduction of roughly one wet night per week versus placebo during treatment, with high relapse rates after stopping. In nocturia due to nocturnal polyuria, the registration trials for the low-dose sublingual (Nocdurna, dosed by sex: 27.7 mcg for women and 55.3 mcg for men, equivalent to 25 and 50 mcg of desmopressin base) and nasal (Noctiva, 0.83-1.66 mcg) formulations showed a reduction of approximately 0.4-1.0 nocturic voids per night versus placebo. For haemostasis, 0.3 mcg/kg intravenously raises factor VIII and von Willebrand factor sufficiently to cover minor procedures in most people with mild haemophilia A or type 1 von Willebrand disease. A population-based cohort study in PLoS Medicine (2019) found hyponatraemia rates of 146 per 1000 person-years among desmopressin users versus 11 per 1000 person-years in comparators, with a roughly 19-fold increased rate in the first 30 days of treatment 1.

Animal and lab research

Animal work was foundational rather than decisive: the Brattleboro rat, which lacks functional vasopressin, was the model in which the antidiuretic effect and the V2/aquaporin-2 mechanism were characterised. Because the clinical evidence in humans is extensive and direct, animal data play essentially no role in current prescribing.

What it is used for

• Central (cranial) diabetes insipidus, also called arginine-vasopressin deficiency 4
• Primary nocturnal enuresis (bedwetting) in children from about 5 years of age
• Nocturia due to nocturnal polyuria in adults who wake at least twice a night to urinate 3
• Mild haemophilia A with factor VIII activity above 5%, and mild to moderate type I von Willebrand disease, to cover minor surgery, dental work or bleeding episodes 4
• Bleeding associated with uraemia, and sometimes bleeding on antiplatelet therapy (off-label, evidence limited)
• As a diagnostic agent in the water deprivation test, to distinguish central from nephrogenic diabetes insipidus
• Off-label and unsanctioned: reducing urine output during long events or travel, and use as a masking or plasma-volume-manipulating agent in sport, which is why WADA lists it. Both applications carry the full hyponatraemia risk without any medical supervision

Dosing

• Central diabetes insipidus, oral tablets: 0.1-0.2 mg two to three times daily, with a usual total of 0.2-1.2 mg per day.
• Central diabetes insipidus, intranasal: 10-40 mcg per day. This is a different formulation from the tablets and the figures do not convert into one another by arithmetic.
• Central diabetes insipidus, subcutaneous or intravenous injection: the DDAVP injection label specifies 2-4 mcg per day as one or two divided doses 4; some references give the range as 1-4 mcg per day. Note that this is micrograms of injected drug against milligrams of oral drug for the same indication.
• Primary nocturnal enuresis, oral, at bedtime: 0.2 mg, titrated by response to a maximum of 0.6 mg.
• Nocturia due to nocturnal polyuria, sublingual, one hour before bedtime: 27.7 mcg in women and 55.3 mcg in men, which is how the Nocdurna label states it 3 — those are milligram-for-milligram the acetate salt, equivalent to 25 and 50 mcg of desmopressin base, so the same dose appears under two numbers depending on which is quoted.
• Haemostasis in mild haemophilia A or type 1 von Willebrand disease, intravenous: 0.3 mcg per kilogram of actual body weight, capped at a maximum of 20 mcg, infused over 15 to 30 minutes 4. This is the only weight-based desmopressin dose, and the cap matters — for anyone over about 67 kg the per-kilogram calculation exceeds the maximum the label allows.
• Fluid restriction is part of the dose. For enuresis and nocturia, the Nocdurna label instructs limiting fluid intake to a minimum from 1 hour before until 8 hours after administration 3. Without this, the drug is materially more dangerous.
• Serum sodium must be normal before starting, and should be checked within 7 days and at approximately 1 month after starting or increasing the dose, then periodically; monitoring should be more frequent in people aged 65 and over 3.
• The sex-differentiated nocturia dose (25 mcg for women, 50 mcg for men) exists because women are more sensitive to desmopressin and had higher hyponatraemia rates at the 55.3 mcg dose in the trials 3.
• Doses given here are the licensed regimens from official product information. This is reference material, not treatment advice; dosing belongs with a prescriber.

Protocols

Schedules are reproduced as their source states them. Units, IU and milligrams explains why the figures are not interchangeable between products.

Reconstitution

Vial sizes

4 mcg/ml ampoules and vials (injection)

Storage

Injection ampoules 2-8 °C. Tablets and sublingual melts at room temperature in the original blister, protected from moisture. Nasal spray refrigerated or at room temperature depending on the specific product; follow the individual package leaflet.

Worked example

Not applicable. Every marketed desmopressin product ships ready to use: tablets, sublingual melts, metered nasal spray, and injection supplied as a sterile aqueous solution. Nothing is reconstituted from powder. For the haemostatic indication the injection is diluted in 0.9% sodium chloride and infused over 15-30 minutes — 50 ml for patients over 10 kg, 10 ml for children of 10 kg or less — but that is dilution before infusion, not reconstitution.

Safety

Side effects

• Hyponatraemia and water intoxication — the central risk. Early signs are headache, nausea, vomiting, lethargy and confusion; severe cases progress to seizures, coma, respiratory arrest and death 3
• Headache, dizziness, nausea and abdominal pain
• Fluid retention, weight gain and peripheral oedema
• Nasal congestion, rhinitis, epistaxis and altered smell with intranasal formulations
• Facial flushing, tachycardia and transient fall in blood pressure with rapid intravenous infusion at haemostatic doses
• Thrombotic events including myocardial infarction and stroke — rare, reported mainly at the higher haemostatic doses in people with existing cardiovascular disease
• Diminishing haemostatic response with repeated dosing (tachyphylaxis), as endothelial stores of von Willebrand factor are depleted 4
• Hypersensitivity reactions, uncommonly

Do not use if

• Known or suspected hyponatraemia, or a history of hyponatraemia 34
• Syndrome of inappropriate antidiuretic hormone secretion (SIADH) 34
• Primary polydipsia or habitual/psychogenic excessive fluid intake 3
• Moderate to severe renal impairment - creatinine clearance below 50 ml/min on the injection label 4, eGFR below 50 ml/min/1.73 m2 on the Nocdurna label 3
• Heart failure or other conditions requiring diuretic treatment 3
• Concomitant loop diuretics, or systemic or inhaled glucocorticoids - an explicit contraindication on both the nocturia and the injection labels 34
• Type IIB von Willebrand disease, where desmopressin carries a thrombosis risk 4
• Uncontrolled hypertension 3, and caution in established coronary or cerebrovascular disease when used at haemostatic doses
• Hypersensitivity to desmopressin or excipients
• Any situation where fluid intake cannot be reliably restricted or serum sodium cannot be monitored

Interactions

The dominant interaction theme is additive hyponatraemia risk. Selective serotonin reuptake inhibitors, tricyclic antidepressants, venlafaxine, carbamazepine, oxcarbazepine, lamotrigine, chlorpromazine, chlorpropamide, opioids and NSAIDs all raise that risk and warrant more frequent sodium monitoring. Loop diuretics and systemic or inhaled glucocorticoids are contraindicated with the nocturia formulations 3. NSAIDs may also enhance the antidiuretic effect directly through prostaglandin inhibition. Drugs that lower the seizure threshold compound the consequences of hyponatraemia. Alcohol, demeclocycline and lithium antagonise the antidiuretic effect. Loperamide markedly increases oral desmopressin absorption.

Sources

• Desmopressin and the risk of hyponatremia: A population-based cohort studyPLoS Medicine, 2019
• NOCDURNA (desmopressin acetate) sublingual tablets - full prescribing information with boxed warning for hyponatremiaUS Food and Drug Administration, 2018
• NOCDURNA - desmopressin acetate tablet, labelDailyMed, US National Library of Medicine
• DDAVP (desmopressin acetate) injection - full prescribing informationDailyMed, Ferring Pharmaceuticals

Related entries

• VasopressinThe body's own antidiuretic hormone, used in intensive care as an intravenous vasopressor in shock.