Hyponatraemia and selective serotonin re‐uptake inhibitors in elderly patients

Abstract

Hyponatraemia (serum sodium arbitrarily defined as less than 135 mmol/L) is an increasingly recognised adverse effect of selective serotonin re-uptake inhibitors (SSRIs). Its precise prevalence and incidence in the elderly are hard to determine because of confounding factors including other prescribed medications and medical conditions. Although hyponatraemia has been reported with all SSRIs and venlafaxine, most studies are small, retrospective, limited by confounding variables or are individual case reports. The risk of developing hyponatraemia while on an SSRI seems to increase with age, female, sex, previous history of hyponatraemia and the concomitant use of other medications known to include hyponatraemia. The sodium concentrations of most patients with SSRI associated hyponatraemia return to normal within days to weeks of SSRI withdrawal. A few cases of SSRI rechallenge indicate that hyponatraemia may sometimes be a transient effect with tolerance developing over time. There is an urgent need for controlled, rigorous studies to confirm the extent of the association between SSRIs and hyponatraemia. Older drugs such as tricyclic antidepressants also need systematic study. It remains quite unclear whether any specific SSRI or venlafaxine has a stronger association with hyponatraemia than any other antidepressant drug.

Duloxetine-induced Hyponatremia in the Elderly

“…This increased osmosensitivity may increase the risk of SIADH. The risk of developing SIADH seems to increase with female sex, previous history of hyponatremia, medical comorbidities, and concomitant drugs known to cause hyponatremia or alter secretion of ADH [8]. Therefore, the diagnosis of SIADH is one of exclusion, when no physiological cause of hyponatremia can be identified or inferred.…”

Hiponatremia in the practice of a psychiatrist. Part 1: SIADH syndrome and drug-induced hyponatremia.

“…According to many reports [22,25], this is often a sufficient method of treatment (in the case of SSRIs, approximately 2 weeks after the withdrawal of the drug, natremia is corrected) [25].…”

“…Giorlando et al, in a retrospective study from 2013, found that risk factors for hyponatremia following SSRI and SNRI were age > 65 years, female sex and sertraline or escitalopram use [37]. Other risk factors for hyponatremia include past events of hyponatremia in the patient, body weight <60 kg, psychotic symptoms [31], female sex [25] and antidepressant combination with diuretics, angiotensin converting enzyme inhibitors (ACEI) or inhibitors of protonic pump (IPP) [34].…”

“…wykazało, że do czynników ryzyka wystąpienia hiponatremii po zastosowaniu leków z grupy SSRI i SNRI należą wiek > 65 roku życia, płeć żeńska oraz zastosowanie sertraliny lub escitalopramu [37]. Wśród innych czynników ryzyka rozwoju hiponatremii można występowanie hiponatremii u pacjenta w przeszłości, masę ciała < 60kg, obecność objawów psychotycznych [31], płeć żeńską [25] oraz stosowanie leków przeciwdepresyjnych w skojarzeniu z diuretykami, inhibitorami konwertazy angiotensyny (ACEI) lub inhibitorami pompy protonowej (IPP) [34].…”

“…W przypadku pacjentów leczonych psychiatrycznie, przyczynowym leczeniem SIADH będzie najczęściej odstawienie leku, który wywołał zaburzenia elektrolitowe [22]. Wg wielu doniesień [22,25], często jest to wystarczająca metoda leczenia (w przypadku leków z grupy SSRI najczęściej po około 2 tygodniach od odstawienia leku natremia ulega wyrównaniu) [25].…”