What are the treatment options for nocturia (nocturnal polyuria)?

Treatment of Increased Frequency of Urine at Night (Nocturia)

Begin with lifestyle modifications including evening fluid restriction to ≤200 ml (6 ounces) after dinner, medication timing adjustments, and treatment of underlying medical conditions; if nocturia persists despite these measures and nocturnal polyuria is confirmed, add desmopressin 0.2 mg (men) or 0.1 mg (women) taken 1 hour before bedtime. 1, 2

Step 1: Confirm Diagnosis and Identify Underlying Cause

Complete a 72-hour frequency-volume chart (bladder diary) to document:

• Number of nighttime voids
• Volume of each void
• Total 24-hour urine output
• Timing of fluid intake 3, 2

Nocturnal polyuria is defined as >33% of 24-hour urine output occurring at night and is the most common cause of nocturia. 1, 4

Screen for underlying medical conditions using the "SCREeN" framework:

• Sleep disorders: Ask about snoring, gasping at night, daytime sleepiness (obstructive sleep apnea is a major contributor) 3
• Cardiovascular: Check for ankle swelling, shortness of breath, history of heart failure 3
• Renal: Review kidney function tests, check urine albumin:creatinine ratio 3
• Endocrine: Assess for diabetes, thyroid disorders, hypercalcemia 3
• Neurological: Evaluate for Parkinson's disease, autonomic dysfunction, cognitive impairment 3

Baseline laboratory tests should include:

• Electrolytes and renal function
• Thyroid function
• Calcium
• HbA1c
• Urinalysis 3

Step 2: First-Line Treatment - Lifestyle Modifications

Fluid management (most critical intervention):

• Limit evening fluid intake to ≤200 ml (6 ounces) after dinner 1, 2
• Maintain adequate daytime hydration, especially morning and early afternoon 3, 1
• Avoid caffeine and alcohol in the evening 5, 6

Medication timing review:

• Adjust diuretic dosing to earlier in the day (ideally morning) to avoid peak effect at night 3
• Review diabetes medications, antiparkinsonian drugs, and other medications that may affect urine production 3

Additional lifestyle measures:

• Encourage moderate daily physical exercise 3, 6
• Treat constipation if present (use polyethylene glycol) 3
• Implement sleep hygiene measures 3, 5
• Keep warm in bed (cold can trigger diuresis) 6
• Elevate legs in the afternoon if peripheral edema is present 5

These lifestyle modifications alone improve nocturia in approximately 53% of patients. 6

Step 3: Treat Underlying Medical Conditions

Prioritize treatment of the underlying medical condition over nocturia symptom relief when there is a therapeutic conflict. 3

Obstructive sleep apnea: CPAP therapy can substantially reduce nocturia, but ensure patient compliance 3

Heart failure: Optimize cardiac medications; nocturia may improve with better fluid balance 3

Restless legs syndrome: Check ferritin level; supplement if <75 ng/ml 3

Benign prostatic hyperplasia (in men): Consider alpha-blockers (tamsulosin 0.4 mg daily) if reduced bladder capacity is contributing 7, 5

Overactive bladder: Consider antimuscarinics or beta-3 agonists if urgency and small-volume voids are present 5, 4

Step 4: Pharmacological Treatment with Desmopressin

Desmopressin is indicated when:

• Nocturnal polyuria is confirmed (>33% of 24-hour output at night) 1, 4
• Lifestyle modifications have been implemented for at least 4 weeks without adequate response 8
• Normal bladder capacity is present (not primarily a bladder storage problem) 3, 4

Dosing:

• Men: Start with 0.2 mg oral tablet or 120 μg oral melt formulation 1
• Women: Start with 0.1 mg oral tablet or 60 μg oral melt formulation (women are at higher risk of hyponatremia) 8
• Take 1 hour before bedtime 1
• Can titrate up to maximum 0.4 mg (tablets) or 240 μg (melt) based on response 1

Critical safety monitoring for desmopressin:

• Check serum sodium before starting treatment 9
• Recheck sodium within 7 days of initiation 9
• Recheck again at 1 month, then periodically 9
• More frequent monitoring in patients ≥65 years 9

Absolute contraindications to desmopressin:

• Polydipsia (excessive fluid intake) 1, 9
• Current hyponatremia 9
• Use of loop diuretics or systemic/inhaled glucocorticoids 9
• Conditions causing fluid/electrolyte imbalances 9

Desmopressin reduces nocturnal voids by approximately 1-2 episodes per night in responders. 4, 8

Step 5: Combination Therapy When Needed

If nocturia persists despite desmopressin and nocturnal polyuria is controlled, consider adding:

• Alpha-blocker (tamsulosin) if benign prostatic hyperplasia is present 5
• Antimuscarinic or beta-3 agonist if overactive bladder symptoms persist 5, 4

This combination approach addresses both nocturnal polyuria and bladder storage issues. 4, 8

Common Pitfalls and Safety Considerations

Do not assume a medical condition is causing nocturia without confirming improvement when the condition is treated. A clear temporal relationship between treatment and nocturia reduction must be established. 3

Avoid desmopressin in patients who drink excessive fluids (>2.5 L per day) or cannot restrict evening fluid intake, as this dramatically increases hyponatremia risk. 9, 8

In older adults (≥65 years), start with lower desmopressin doses and monitor sodium more frequently due to increased risk of hyponatremia. 3, 9

Address fall risk in all patients with nocturia, as nighttime bathroom trips significantly increase fall and fracture risk, especially in older adults. 2, 5

Refer to urology if:

• Hematuria is present 3
• Severe lower urinary tract symptoms suggest obstruction 3
• Neurological symptoms suggest neurogenic bladder 3
• Nocturia persists despite optimal medical management 3

Set realistic expectations with patients: Some medical conditions (well-controlled diabetes, chronic kidney disease, heart failure) may cause persistent nocturia despite optimal treatment, and complete resolution may not be achievable. 3