Early serum sodium changes in elderly patients with nocturia receiving desmopressin

The purpose of the study is to identify early serum sodium changes that could happen in elderly patients with nocturia receiving desmopressin.

This study was conducted on 28 patients complaining of nocturia and receiving desmopressin. Inclusion criteria were patients diagnosed as having nocturia (at least one or more voids per night) aging ≥55 years with normal baseline serum sodium (135-150 mEq/L). All patients received desmopressin in the form of 60 μg at bedtime. Close follow-up was done for any adverse effects that may have occurred related to hyponatremia and serum sodium was reevaluated for all patients at 3, 7, 14, and 30 days from the start of the treatment.

Desmopressin resulted in a significant decrease in nocturnal urine volume, a decrease in nocturnal polyuria index, number of night voids and the time to first void was delayed. Furthermore, statistically insignificant sodium drop in males and statistically significant sodium drop in females were noted with infrequent side effects, for example, headache (10.7%) and hyponatremia (7.14%) that started after treatment by 1 week.

Hyponatremia can be avoided using the minimal effective dose of desmopressin. To receive desmopressin in elderly patients sodium baseline level must be ≥135 mmol/L. Close sodium monitoring has to be done at 7, 14, and 30 days from start of treatment for high-risk patients (especially elderly) or patients receiving other medication causing hyponatremia.