Reactions 1290 - 27 Feb 2010

SCitalopram

QT-interval prolongation in an elderly patient:case report

A 76-year-old woman developed QT-intervalprolongation during treatment with citalopram for chronicdepression [duration of treatment to reaction onset notstated].

The woman, whose history included Alzheimer’sdisease, rheumatoid arthritis and a paranoid schizophrenicepisode, was hospitalised after collapsing on her way to thebathroom. On admission, she was in mildly reduced state,but showed no other conclusive pathology. An ECGrevealed bradycardia of 55/min, a QT interval of 526ms anda QTc interval of 503ms; she also had hypokalaemia of3.4 mmol/L. At that time, her medication includedcitalopram 20 mg/day, olanzapine, methotrexate,prednisone, folic acid and atorvastatin.

Citalopram and olanzapine were discontinued. Two dayslater, an ECG showed a normal sinus rhythm with a HR of65/min, and a normal QT interval of 410ms (QTc interval428ms). Her therapy was changed to escitalopram;olanzapine was currently not indicated and therefore notrestarted. On day 2, a 24h ECG was largely normal, withoutarrhythmias apart from isolated supraventricular andventricular extrasystoles. A Schellong test was pathologicalwith a 26mm Hg drop in her systolic BP. Five days afteradmission, a repeat ECG was normal with a HR of 58/min, aQT interval of 412ms and a QTc interval of 408ms. Hercollapse was interpreted as orthostatic syncope.

Review of her history later revealed severalhospitalisations for syncopes during the previous years.Three years before the current event, while she wasreceiving citalopram 40 mg/day, the hospital work-up haddisclosed a prolonged QT interval and hypokalaemia. Oneand a half years later, she was hospitalised while receivingcitalopram, olanzapine, and after taking a dose ofoxazepam; on that occasion, her QT interval hadnormalised following a reduction in her citalopram dosageto 20 mg/day. On her last admission about 0.5 years later,she was again receiving citalopram 40 mg/day, and had aprolonged QT interval and mild hypokalaemia.

Author comment: Given the known association betweencitalopram intake and prolonged QT duration, immediateregression of QT duration after discontinuation or dosereduction, and new QT prolongation following re-exposure tocitalopram, causality between citalopram intake and onset ofQT/QTc prolongation can be considered at least likely.Bruggisser M, et al. Drug-induced long QT syndrome. Praxis 98: 1409-15, No. 24,2 Dec 2009 [German] - Switzerland 803006452

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Reactions 27 Feb 2010 No. 12900114-9954/10/1290-0001/$14.95 © 2010 Adis Data Information BV. All rights reserved