Reactions 1073 - 15 Oct 2005

SCitalopram

Inappropriate antidiuretic hormone secretion in anelderly patient: case report

An 81-year-old woman developed inappropriate antidiuretichormone secretion during treatment with citalopram[therapeutic indications not clearly stated].

The woman, who had been treated with amitriptyline for2 years, started receiving citalopram [dosage not stated]because her depressive symptoms did not improve; otherconcomitant medication included ramipril, bisoprolol,amlodipine and moxonidine. Two months later, she washospitalised with a 5-day history of confusion, drowsiness,reduced food intake, vomiting and stupor. Laboratoryinvestigations revealed a serum sodium level of 112 mmol/L(normal 135–152) and a serum osmolality of 225 mOsm/kgH2O (280–300), with inappropriately normal urine osmolalityand urinary sodium. She was diagnosed with inappropriateantidiuretic hormone secretion after other cases ofhyponatraemia were excluded.

Amitriptyline and citalopram were discontinued. Thewoman received saline solution and, within 1 day, her serumsodium level was increased to 120 mmol/L. After 3 days, shewas put on a fluid restriction and received sodium chloridetablets. Within the following 9 days, her serum sodium levelwas 136 mmol/L and her symptoms improved, but she was notfully orientated until day 15. No further antidepressanttreatment was started.

Author comment: "Hyponatraemia developed shortly aftertherapy with citalopram had been started and, therefore, wasmost likely related to the initiation of citalopram therapy,possibly in combination with amitriptyline. Except foramitriptyline and citalopram the patient continued treatmentwith her previous medications. For amlodipine and ramipril,also taken by the patient, hyponatraemia is reported as well.However, citalopram is the only drug that has been added ormodified."Miehle K, et al. Citalopram therapy as a risk factor for symptomatic hyponatremiacaused by the syndrome of inappropriate secretion of antidiuretic hormone(SIADH): a case report. Pharmacopsychiatry 38: 181-182, No. 4, Jul 2005 -Germany 801018466

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Reactions 15 Oct 2005 No. 10730114-9954/10/1073-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved