Desmopressin
Minirin · Nocutil · Octostim · Desmopressin Ferring
The same substance is used for four entirely different indications with doses differing up to a hundredfold — antidiuretic substitution in central diabetes insipidus, symptom relief in nocturia and nocturnal enuresis, and haemostatic release of von Willebrand factor and factor VIII. Selectivity for the V2 receptor means it lacks the vasoconstrictive effect of vasopressin. The danger is not the drug itself but the fluid the patient drinks with it.
Hyponatraemia with seizures and impaired consciousness is the dominant serious risk and occurs when the patient drinks freely during ongoing antidiuresis. Fluid restriction from one hour before to eight hours after the dose is a prerequisite, and sodium must be monitored in older patients.
Dosing in adults
| Indication | Regimen | Comment |
|---|---|---|
| Central diabetes insipidus | 0,1–0,2 mg orally 2–3 times daily, or 10–20 μg intranasally 1–2 times daily | titrate against urine output and sodium |
| Nocturia in adults | 25 μg (women) or 50 μg (men) sublingually at bedtime | contraindicated when sodium is below the reference range and in patients over 65 years without monitoring |
| Primary nocturnal enuresis, children ≥ 5 years | 120–240 μg sublingually (0,2–0,4 mg orally) at bedtime | no fluids from 1 hour before to 8 hours after the dose |
| Mild haemophilia A and von Willebrand disease type 1 | 0,3 μg/kg iv in 50 ml NaCl over 20–30 minutes, or 300 μg intranasally | factor levels rise 2–4 fold; tachyphylaxis after 2–3 doses |
| Uraemic platelet dysfunction with bleeding | 0,3 μg/kg iv as a single dose | effect within 1 hour, lasts 4–8 hours |
Contraindicated at eGFR < 50 ml/min for the nocturia and enuresis indications. In central diabetes insipidus the drug is given but with more frequent sodium monitoring. In uraemic bleeding it is used as a haemostat despite the renal failure.
No established dose adjustment; caution in cirrhosis with ascites and ongoing fluid retention.
Nocturnal enuresis from age 5, 120–240 μg sublingually at bedtime. Fluid restriction is especially important in children and the dose should be paused during gastroenteritis or febrile illness.
Do not confuse the formulations. The injection solution for haemostasis is almost four times more concentrated than the one for diabetes insipidus, and the sublingual tablet for nocturia is dosed in micrograms while the tablet for diabetes insipidus is dosed in milligrams — a thousandfold difference.
Pharmacokinetics
- BIOAVAIL.
- 0,1–0,2 % orally, 3–5 % intranasally
- t½
- 3–4 hours
- ONSET (antidiuresis)
- 30–60 minutes orally
- DURATION (antidiuresis)
- 6–14 hours
- ONSET (haemostasis)
- 30–60 minutes iv, maximum factor effect after approximately 90 minutes
- METABOLISM
- Peptide degradation, no CYP metabolism
- EXCRETION
- Renal
- TACHYPHYLAXIS
- Haemostatic effect diminishes after 2–3 doses within 48 hours