Factors Associated with Hyponatremia in Patients Newly Prescribed Citalopram: A Retrospective Observational Study

Abstract

Background Hyponatremia is a common and under-recognized adverse drug reaction of selective serotonin re-uptake inhibitor (SSRI) antidepressants. Despite its clinical importance, there are few large-scale studies on the factors associated with hyponatremia.Objective The aim of this study was to determine the incidence of hyponatremia and to identify patient factors associated with hyponatremia in a large, population-based cohort initiating new prescriptions for citalopram. Methods We included all patients with a new prescription for citalopram during 2010-2017, inclusive, with baseline and post-initiation serum sodium values available. Data were obtained from an Alberta Health Pharmacy database to identify new citalopram prescriptions. Laboratory values for patients with new prescriptions were obtained from linked Calgary Laboratory Services data. Incident hyponatremia was defined as serum sodium level < 135 mmol/L, following prescription initiation. Associations were determined by performing Cox regression with time-varying covariate analysis, with the development of hyponatremia as the dependent variable. Results A total of 19,679 patients with new prescriptions were identified; 12,842 females and 6837 males. The mean age was 55.48 years (SD 21.35). Of these patients, 3250 (16.5%) developed hyponatremia, 1996 (15.5% of) females and 1254 (18.3% of) males (p = 0.002). Cox regression showed significant associations of hyponatremia with lower baseline sodium (HR 0.788), older age (HR 1.029), thiazide diuretic use (HR 1.141), and male sex (HR 1.168). Pharmaceutical manufacturer or strength of citalopram did not have significant effects on the development of hyponatremia. ConclusionThis study provides additional data on the predictors of hyponatremia among patients initiating citalopram therapy. We report a 16.5% incidence of hyponatremia after starting citalopram treatment, and significant new findings include a higher incidence in males. This is the first published incidence of hyponatremia following the initiation of citalopram treatment across all ages in Canada.

Study on the feasibility of pharmacist intervention on management of antidepressant treatment in late life depression under MDT: a mixed methods study

“…ADEs caused by antidepressants can aggravate or mask the related symptoms, such as dry mouth dysuria, which can aggravate urinary system reactions in patients with prostatic hyperplasia [22]. Drug-related risk increases in elders such as bleeding [23], hyponatremia [24], orthostatic hypotension [25], bone density decrease [26], and falls due to long-term or even lifetime medication. At the same time, antidepressant is more likely to increase the risk of ADEs because of complicated prescription in elderly patients [27,28].…”

Eslicarbazepine‐induced hyponatremia: A retrospective single‐center real clinical practice study

“…1,7,9,10 Citalopram is a widely used antidepressant causing hyponatremia (with a reported 16.5% prevalence of hyponatremia after starting treatment); we particularly explored citalopram administration as a covariable related to hyponatremia. 12 Only patients with known natremia before ESL administration were included in the study. Patients with hyponatremia before ESL administration were excluded, with the exception of patients with previously documented CBZ-induced hyponatremia (switching from CBZ).…”

“…Following the results of earlier studies, age, gender, antidiuretic drugs, and other (than diuretic) drugs causing hyponatremia were counted as covariables related to hyponatremia 1,7,9,10 . Citalopram is a widely used antidepressant causing hyponatremia (with a reported 16.5% prevalence of hyponatremia after starting treatment); we particularly explored citalopram administration as a covariable related to hyponatremia 12 …”

“… 1 , 7 , 9 , 10 Citalopram is a widely used antidepressant causing hyponatremia (with a reported 16.5% prevalence of hyponatremia after starting treatment); we particularly explored citalopram administration as a covariable related to hyponatremia. 12 …”