Desmopressin in Elderly Patients With Nocturia: Short-Term Safety and Effects on Urine Output, Sleep and Voiding Patterns
Rembratt A, Norgaard JP, Andersson KE.
BJU Int. 2003;91:642–646.
In this study, Rembratt and colleauges investigated the short-term safety of desmopressin in elderly patients with nocturia, with a special focus on the risk of hyponatremia, and assessed the agent’s short-term effects on urine output, sleep, and voiding patterns.
Seventy-two men and women older than 65 years were recruited from a study that used frequency-volume charts, which in turn was preceded by a questionnaire study. Each patient received a 0.2-mg desmopressin tablet at bedtime for 3 consecutive nights and maintained a frequency-volume chart. Serum sodium was assessed in the mornings after the first and the third dose. Patients with a mean serum sodium level during treatment deviating more than 5 units from baseline were considered sensitive to change in serum sodium. Potential predictors for sodium sensitivity and response were investigated with logistic and multiple regression.
All 72 enrolled patients completed the trial. No serious adverse events occurred, and no adverse events of severe intensity were recorded. Six patients were sensitive to change in serum sodium. The risk increased with increasing age (odds ratio [OR], 1.3), concomitant cardiac disease (OR, 10.0), and increasing baseline 24-hour urine output (OR, 1.2). Patients who were sensitive to change in serum sodium were pharmacologic responders, and desmopressin had a greater effect on their 24-hour diuresis.
Although this study concluded that desmopressin is generally safe in the elderly, several concerns remain. The study cohorts were all Caucasian (Swedes) and in good health. None smoked or consumed alcohol to excess (mean, 0.8 units ethanol/wk). It is not known whether desmopressin’s safety in this group of healthy Norwegians would translate to the ethically diverse US elderly population, with its multiple medical problems. In addition, acceptable sodium levels after 3 days of treatment does not guarantee that the drug is safe after 1 month or 1 year of administration. Several of my patients have presented to the emergency department with confusion and were subsequently found to have sodium levels less than 125 mmol/L after taking stable does of desmopressin for weeks to months.
Overall, I believe that desmopressin is a safe and effective drug, and I have had success with this treatment in adult neurogenic bladder patients. However, use of desmopressin in the elderly, even if apparently healthy, should be initiated with considerable caution.