Clinical Question: Is there an increased risk of hyponatremia for older patients who are taking a second-generation antidepressant?
Background: Mood and anxiety disorders affect about one in eight older adults, and second-generation antidepressants are frequently recommended for treatment. A potential adverse effect of these agents is hyponatremia, which can lead to serious sequelae. The aim of this study was to investigate the 30-day risk for hospitalization with hyponatremia in older adults who were newly started on a second-generation antidepressant.
Study design: A retrospective population-based cohort study of older adults from 2003 to 2012 using linked health care databases.
Setting: Ontario, Canada.
Synopsis: Multiple databases were utilized to obtain vital statistics and demographic information, diagnoses, prescriptions, and serum sodium measurements to establish a cohort population. One group of 172,552 was newly prescribed a second-generation antidepressant. A second control group of 297,501 was established in which patients were not prescribed antidepressants. Greedy matching was used to match each user to a nonuser based on similar characteristics of age, sex, evidence of mood disorder, chronic kidney disease, congestive heart failure, or diuretic use. After matching, 138,246 patients remained in each group and were nearly identical for all 10 0 measured characteristics. The primary outcome was that, compared with nonuse, second-generation antidepressant use was associated with higher 30-day risk of hospitalization with hyponatremia (relative risk, 5.46; 95% CI, 4.32-6.91). The secondary outcome showed that, compared with non-use, second-generation antidepressant use was associated with higher 30-day risk for hospitalization with concomitant hyponatremia and delirium (RR, 4.00; 95% CI, 1.74 – 9.16). Additionally, tests for specificity and temporality were employed.
Bottom Line: A robust association between second-generation antidepressant use and hospitalization with hyponatremia was determined in the large population-based cohort study.
Citation: Gandhi S, Shariff SZ, Al-Jaishi A, et al. “Second-generation antidepressants and hyponatremia risk: a population-based cohort study of older adults.”.
is clinical assistant professor in the division of hospital medicine, Loyola University Chicago, Maywood, Ill.