The December 2011 issue of Drug Safety Update from the MHRA includes an article advising healthcare professionals of new data concerning the risk of QT interval prolongation with citalopram and escitalopram. 

The potential for QT citalopram and escitalopram to cause QT interval prolongation has been known for some time and is reflected in the product information.  New data have however become available allowing clarification of the risks and their dose-dependency; new maximum daily dose restrictions (including in elderly patients), contraindications, and warnings have been issued as a result.  The article summarises the new data and resulting recommendations for both agents – please see the link below for further details.

Of note, the maximum daily doses for citalopram are now as follows: 40mg for adults; 20mg for patients older than 65 years; and 20mg for those with hepatic impairment.  For escitalopram, the maximum daily dose for patients older than 65 years is now reduced to 10mg/day; other doses remain unchanged.  Patients who currently take doses higher than the new recommended daily maximum should have their treatment reviewed.