Use of an older formulation of desmopressin, which is sometimes prescribed off-label for treating nocturia, may increase the risk of hyponatremia compared with the use of other drugs indicated for the treatment of lower urinary tract symptoms, according to a study.
“Quantifying the potential risks facing adult patients taking desmopressin has taken on added importance because a new intranasal formulation of desmopressin was approved by the FDA in 2017,” investigators Michael Fralick, MD, of Brigham and Women’s Hospital and Harvard Medical School in Boston, and colleagues wrote in an online report in PLOS Medicine. “Like the old formulation, the main active ingredient is desmopressin acetate, but the new formulation also contains an excipient designed to enhance absorption.”
Using a nationwide US commercial claims database, Dr Fralick’s team identified 3137 adults who were newly prescribed the older formulation of desmopressin and propensity score matched them to 3137 adults who were newly prescribed oxybutynin, another medication sometimes used to treat nocturia but which is not associated with hyponatremia. The study included only patients older than 50 years.
The rate of hyponatremia was 146 episodes per 1000 person-years with desmopressin compared with about 11 episodes per 1000 person-years among oxybutynin recipients, a 13-fold higher rate of hyponatremia in the desmopressin group, according to the investigators.
Dr Fralick and his colleagues also compared adults newly prescribed desmopressin use with propensity score matched cohort of adults newly prescribed tamsulosin and found that, compared with the tamsulosin group, desmopressin users had a 12-fold higher rate of hyponatremia.
“The potential risk of hyponatremia should be considered prior to prescribing this older formulation of desmopressin,” the authors noted.
Fralick M, Schneeweiss S, Wallis CJD, et al. Desmopressin and the risk of hyponatremia: A population-based cohort study [published online October 21, 2019]. PLoS Med. 2019;16(10):e1002930.