What is the recommended evaluation and treatment for nocturnal enuresis in a 32‑year‑old man?

Treatment for Adult Nocturnal Enuresis (Bedwetting)

A 32-year-old man with nocturnal enuresis requires systematic evaluation to exclude underlying medical causes before initiating treatment with desmopressin as first-line pharmacotherapy, combined with enuresis alarm therapy for long-term cure.

Initial Diagnostic Evaluation

The evaluation must distinguish between monosymptomatic enuresis (bedwetting only) and non-monosymptomatic enuresis (bedwetting plus daytime urinary symptoms), as this fundamentally changes the treatment approach 1, 2.

Essential History Components

• Voiding pattern documentation: Complete a 72-hour bladder diary to quantify nighttime urine volume and frequency 3, 4
• Daytime symptoms: Ask specifically about urgency, frequency, or daytime incontinence to identify non-monosymptomatic cases 1, 5
• Sleep quality: Screen for obstructive sleep apnea using STOP-BANG questionnaire, asking "Have you been told that you gasp or stop breathing at night?" 1, 6
• Fluid intake patterns: Document evening fluid consumption, caffeine, and alcohol use 3
• Medication review: Identify diuretics, calcium channel blockers, lithium, NSAIDs, and medications causing dry mouth (anticholinergics, antidepressants, antihistamines) 1, 3

Physical Examination Priorities

• Neurological assessment: Check for lower limb weakness, gait abnormalities, speech disturbances, or tremor that suggest neurological disease 1
• Cardiovascular signs: Examine for peripheral edema suggesting heart failure 1
• Orthostatic blood pressure: Measure sitting and standing blood pressure; a drop of 20 mmHg systolic or 10 mmHg diastolic indicates autonomic dysfunction 1, 3

Required Laboratory Tests

• Blood work: Electrolytes, renal function, thyroid function, calcium, and HbA1c to screen for diabetes, kidney disease, and endocrine disorders 3, 4
• Urinalysis: Check albumin-to-creatinine ratio and dipstick for blood/protein 3, 4
• Morning urine osmolarity: If 24-hour urine output exceeds 2.5 liters, test morning urine osmolarity after overnight fluid restriction; values below 600 mosm/L suggest diabetes insipidus 1, 6

Screening for Underlying Medical Causes

Do not assume this is simple bedwetting—adult enuresis often has identifiable medical causes that require specific treatment 1, 3.

Sleep Disorders (Most Common Overlooked Cause)

• Obstructive sleep apnea: Refer for overnight oximetry if STOP-BANG is positive or patient reports witnessed apneas 1, 6
• Restless legs syndrome: Check ferritin level; supplement if below 75 ng/mL 1

Cardiovascular Disease

• If heart failure suspected: Order ECG and brain natriuretic peptide; proceed to echocardiogram if positive 1

Neurological Red Flags

• Immediate neurology referral if patient has new-onset severe urinary symptoms, numbness, weakness, speech disturbance, gait problems, or memory impairment 1

Endocrine Disorders

• Evaluate for diabetes mellitus (HbA1c), hypercalcemia (calcium and parathyroid hormone), and thyroid disease 1, 6

Treatment Algorithm

Step 1: Behavioral Modifications (All Patients)

• Fluid restriction: Limit intake after 6 PM 3
• Eliminate bladder irritants: No evening caffeine or alcohol 3
• Optimize medication timing: Move diuretics to afternoon dosing 1, 3
• Address constipation: Treat fecal impaction if present 6

Step 2: First-Line Pharmacotherapy (Monosymptomatic Cases)

Desmopressin 0.2-0.4 mg orally at bedtime is the primary medication for adults with monosymptomatic nocturnal enuresis 7, 8.

• Expected response: 66% achieve continence (≤1 wet night per month) on desmopressin 7
• Critical safety warning: Strict fluid restriction after dosing is mandatory to prevent hyponatremia; monitor serum sodium, especially in older adults 3
• Limitation: Only 7% remain dry after stopping desmopressin, indicating high relapse rate 7

Step 3: Enuresis Alarm Therapy (For Long-Term Cure)

Enuresis alarm therapy for 6 months produces the highest long-term cure rate and should be initiated if desmopressin fails or after desmopressin discontinuation 1, 7.

• Success rate: 33% achieve continence off all medications with alarm therapy alone 7
• Advantage: More likely to produce permanent resolution compared to medication 1, 9
• Duration: Requires 6 months of consistent use 7

Step 4: Combination Therapy (Refractory Cases)

If alarm therapy fails or patient has detrusor overactivity on urodynamics:

• Add anticholinergic medication: Tolterodine 4 mg daily can be combined with desmopressin 8
• Urodynamic findings: 50% of adults with persistent enuresis have detrusor instability, 40% have bladder hypocompliance 8
• Combined success rate: Desmopressin plus anticholinergic achieves 86% continence rate 8

Step 5: Alternative Medication (Treatment-Resistant Cases)

• Imipramine 50 mg nightly: Reserve for patients unresponsive to desmopressin and alarm therapy; achieves continence in 29% of refractory cases 7

Special Considerations for Non-Monosymptomatic Enuresis

If daytime urinary symptoms are present, treat the underlying bladder dysfunction before addressing nocturnal enuresis 1, 5.

• Overactive bladder with urgency requires anticholinergic therapy first 5
• Urodynamic studies may be warranted to identify detrusor overactivity or bladder outlet obstruction 8

When to Refer to Urology

• Refractory cases: Persistent enuresis after 6 months of desmopressin, alarm therapy, and combination treatment 7
• Suspected anatomical abnormalities: Hematuria, elevated post-void residual, or abnormal physical examination 3, 9
• Non-monosymptomatic enuresis: Daytime symptoms suggesting bladder dysfunction 1, 9
• Neurological concerns: Signs of spinal cord pathology or neurogenic bladder 1, 6

Common Pitfalls to Avoid

• Assuming benign prostatic hyperplasia in men: Adult enuresis has multiple non-urological causes that must be systematically excluded 3
• Overlooking sleep apnea: OSA is a major contributor to nocturnal enuresis through increased arousals and light sleep 6
• Ignoring medication contributions: Drugs causing xerostomia increase fluid intake and worsen enuresis 1, 3
• Premature discontinuation of alarm therapy: Requires full 6-month trial for maximum benefit 7
• Failure to monitor sodium with desmopressin: Hyponatremia risk necessitates baseline and follow-up electrolyte monitoring 3

Expected Outcomes

Overall, 83% of adults with persistent primary nocturnal enuresis achieve continence with systematic treatment 7:

• 38% become continent off all medications (primarily with alarm therapy)
• 45% require maintenance pharmacotherapy (desmopressin or imipramine)
• 17% remain refractory to all interventions