Pharmacotherapy for nocturia in the elderly patient

Nocturia may be attributable to nocturnal polyuria (nocturnal urine overproduction), a diminished nocturnal bladder capacity or a combination of the two conditions. A disorder of the vasopressin (antidiuretic hormone) system with very low or undetectable levels of vasopressin at night, affecting some elderly people, may cause an increase in the nocturnal urine output, which in the most extreme cases accounts for 85% of the 24-hour diuresis. The increased urine output can be treated with desmopressin orally at bedtime, generally using low doses. Self-imposed fluid restrictions before bedtime are not effective in reducing the nocturnal urine output in this condition. Nocturia is also more prevalent in association with a reduced bladder capacity. Antimuscarinic drugs are used in attempts to depress involuntary bladder contractions. Decreased nocturnal voided volumes in men and consequent increased nocturia may suggest difficulty in emptying the bladder or detrusor overactivity. alpha(1)-Adrenoceptor antagonists and 5 alpha-reductase inhibitors are often used in men with symptoms indicative of benign prostatic hyperplasia, and one of their effects is reduction of nocturia. In women, estrogen deficiency, a common consequence of the menopausal transition, causes atrophic changes within the urogenital tract. Consequently, such women are more disposed to having urogenital symptoms, among them nocturia. This review emphasises the importance of correctly diagnosing and treating nocturia in elderly patients. This will improve patients' sleep and, in turn, reduce their risk of fall injuries and the associated detrimental consequences, thereby improving patients' health and quality of life.