Minirin (Desmopressin) Dosing for Nocturnal Polyuria
For adults with nocturnal polyuria, start with oral desmopressin 25 µg for women or 50 µg for men taken one hour before bedtime, with mandatory fluid restriction to 200 ml (6 ounces) or less in the evening and no drinking until morning. 1, 2, 3
Dosing Regimens by Formulation
Oral Tablets (Standard)
- Initial dose: 0.2 mg (200 µg) taken at least 1 hour before sleep 1, 2
- Dose range: 0.2-0.4 mg depending on response 1, 2
- Maximum renal concentrating effect: Occurs 1-2 hours after administration 1
Oral Melt Tablets (Lyophilisate/MELT Formula)
- Women: Start with 25 µg 3
- Men: Start with 50 µg 3
- Timing: 30-60 minutes before bedtime 2
- Titration: Can increase to maximum 240 µg based on clinical response 2, 4
- Initial titration dose: 60 µg MELT formula, adjustable upward 4
Key Dosing Principles
- Dose is NOT weight or age-dependent 1, 2
- Clinical effect duration: Approximately 8-12 hours 4
- The effect is immediate, allowing families to quickly assess ongoing necessity 1
Critical Safety Requirements
Mandatory Fluid Restriction
- Limit evening fluid intake to 200 ml (6 ounces) or less 1, 2
- No drinking from 1 hour before desmopressin until morning (8 hours after dose) 1, 2, 4
- This restriction is essential to prevent water intoxication with hyponatremia and convulsions 1, 2
Absolute Contraindications
- Polydipsia (excessive thirst/drinking) is an absolute contraindication 1, 2
- Cardiac failure patients should not receive desmopressin due to fluid retention risk 5
Formulation Safety
- Avoid nasal spray formulations due to higher risk of hyponatremia and water intoxication 1, 2
- Oral formulations are strongly preferred 1
Monitoring and Management
Baseline Assessment
- Confirm nocturnal polyuria: Nocturnal polyuria index ≥0.33 (>33% of 24-hour urine volume produced overnight) 6, 3, 5
- Bladder diary: Maintain for at least 2-3 days (72 hours minimum) 1, 6
- Urine dipstick: Mandatory to rule out glycosuria and proteinuria 1
Ongoing Monitoring
- Serum sodium monitoring: Especially critical in patients over 65 years of age who have higher hyponatremia risk 4
- Watch for hyponatremia symptoms: Headache, nausea, and insomnia 4
- Regular drug holidays: Schedule short breaks to assess whether medication is still needed 1, 2
Adverse Events
- Most common side effects: headaches, nausea, diarrhea, abdominal pain, dry mouth 4
- Hyponatremia occurred in 12% of patients in one study 6
- Overall adverse events were mostly mild but more frequent than placebo 4
Expected Outcomes
Efficacy Rates
- Effectiveness range: 10-65% with potential for relapse 2
- Reduction in nocturnal frequency: Significant with 40 µg dose 5
- Nocturnal urine volume reduction: Significant decrease in percentage of urine passed at night 5
- Patient satisfaction: 72.6% considered treatment efficacious in one study 6
Treatment Failures and Combination Therapy
When Desmopressin Alone Fails
- Consider adding anticholinergics (tolterodine, oxybutynin, or propiverine) if detrusor overactivity is present 7, 1, 2
- Approximately 40% of treatment-resistant patients respond to combination therapy 1
Alternative Strategy for Resistant Cases
- Morning furosemide (0.5 mg/kg) plus desmopressin may benefit patients with desmopressin-resistant nocturnal polyuria 8
- This shifts sodium and osmotic excretion to daytime, reducing nocturnal diuresis 8
- In one pilot study, 9 of 12 resistant patients achieved continence with this combination 8
Evidence Quality
The recommendation for desmopressin in nocturnal polyuria has Level 1b evidence with Grade A recommendation according to Evidence Based Medicine criteria 4. This represents high-quality evidence from randomized controlled trials supporting its use as first-line pharmacological therapy.