Nocturia.

A 52-year-old man complains of minor urgency and frequency during the day and nocturia × 3-5. His DRE reveals a 30-g benign prostate. He is started on tamsulosin, and his daytime symptoms resolve entirely; however, he still has nocturia × 2-4. He is counseled on lifestyle modifications and to decrease fluid consumption including caffeine but has no improvement in nocturia. Cystoscopy is normal with no evident visual obstruction. A urinalysis is normal. The PVR is 40 ml. He has a normal-sized neck and does not snore. He has no trouble sleeping and awakens because of the urge to void. This is very bothersome.