The aim of the present study was to determine whether the combined administration of a diuretic agent, hydrochlorothiazide, at night would improve the frequency of nocturia unresponsive to alpha-blocker monotherapy in men with LUTS.

Because nocturia may result in sleep disturbances, daytime fatigue, a lower level of general well-being, and an increased risk of falling at night, it is among the most bothersome of the lower urinary tract symptoms (LUTS). Nocturia is related to a variety of conditions such as aging, overactive bladder (OAB), benign prostatic hyperplasia (BPH)/LUTS, medications, diabetes mellitus, diabetes insipidus, anorexia nervosa, and sleep disturbance. In a previous study, we suggested that treatment with terazosin can reduce episodes of nocturia, both subjectively and objectively, in some men with LUTS. Other study showed that in men with nocturnal polyuria, furosemide resulted in a significant reduction in night-time frequency and percentage of the voided volume.

Inclusion Criteria:

• no response or < 25% reduction in subjective nocturia by the IPSS question 7 after 4-weeks of treatment with terazosin
• no response or < 25% reduction in objective nocturia by the FVC after 4-weeks of treatment with terazosin
• nocturia on average two times or more per night (according to the FVC) after 4-weeks of terazosin therapy

Exclusion Criteria:

• use of medications for the control of bladder symptoms
• use of sedatives or tranquillisers for treating sleep disturbances
• bladder tumours
• bladder stones
• urethral strictures
• neurogenic bladder dysfunction
• restricted mobility
• working primarily at night
• a documented history or clinical symptoms of prostatitis, prostate cancer, or prostatic intraepithelial neoplasia on biopsy
• serum PSA levels of >20 ng/mL
• a history of prostate surgery or radiotherapy, acute urinary retention or an indwelling catheter
• evidence of acute urinary infection (pyuria and bacteriuria)on urine analysis