Reactions 963 - 9 Aug 2003

Citalopram

Syndrome of inappropriate antidiuretic hormonesecretion in an elderly patient: case report

A 75-year-old woman started receiving citalopram 20mgonce daily and trazodone after her physician noted that shewas sad. Two weeks later, during complete work-up forabdominal pain, laboratory investigations revealed sodium andchloride levels of 118 and 84 mEq/L, respectively, and serumosmolality of 250 mOsm/kg. A diagnosis of syndrome ofinappropriate antidiuretic hormone secretion (SIADH)secondary to citalopram therapy was made and citalopram,trazodone and concomitant diphenhydramine werediscontinued. SIADH was treated with fluid restriction and hersodium level increased to 123 mEq/L in 3 days.

Author comment: "The likelihood that our case was drug-induced is probable based on the Naranjo probability scale. . .Although it is unlikely that our patient’s hyponatremia wasassociated with trazodone, we cannot rule out that trazodoneplus citalopram may have increased the likelihood of thispatient developing hyponatremia.Ertel GJ, et al. Citalopram-related SIADH. Journal of Pharmacy Technology 19:91-93, Mar-Apr 2003 - USA 800946810

1

Reactions 9 Aug 2003 No. 9630114-9954/10/0963-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved