[Nocturia in men with benign prostatic hyperplasia]

Nocturia, defined as nocturnal micturition with a frequency of at least once per night, is one of the most frequent lower urinary tract symptoms in men with benign prostatic hyperplasia (BPH) and often causes them to consult a physician. Nocturia is often bothersome and responsible for increased morbidity and mortality. Nocturia can be caused by increased fluid intake, increased diuresis or decreased bladder capacity, either alone or in combination. The underlying pathophysiology of nocturia can only be detected by methodical evaluation of the patient. Bladder diaries for 3 days are an essential part of the assessment. Treatment goals include reducing the nocturnal voiding frequency to less than 2 episodes per night, increasing the duration of undisturbed sleep to more than 4 hours, restoring quality of life, and reducing morbidity as well as mortality. In patients with reduced functional bladder capacity, α-blockers, 5α-reductase inhibitors, phosphodiesterase type-5 inhibitors, plant extracts or prostate operations (e. g. TURP) have shown to significantly reduce nocturnal voiding frequency. If nocturnal polyuria causes or contributes to nocturia, as shown in up to 80 % of BPH patients with nocturia, the treatment goal is to reduce urine production during the night. Low nocturnal serum concentration of the antidiuretic hormone can be treated with desmopressin to be taken at bedtime. The risk of hyponatremia is reduced with the new low-dose desmopressin formulation, which can be used even in men older than 65 years of age. Drug combinations may be useful in men with a mixed pathophysiology of nocturia.