The patient experienced a ventricular tachycardia leading to cardiac arrest and was found to have a prolonged QT interval. Although citalopram is eliminated more slowly in patients with mild to moderate renal impairment a dose adjustment is not necessary. However, no information is available on treatment of patients with severely reduced renal function and prescribers are advised to use caution. Chloroquine lupus treatment Plaquenil boils Chloroquine and diazepam What does the drug plaquenil do Keywords Long QT Syndrome, Torsades de pointes, Anesthesia, QT-prolongation, Anesthetic drugs Core tip Long QT syndrome is a cardiac conduction disorder characterized by prolongation and increased dispersion of ventricular repolarization, manifested by lengthening of the QT interval on the surface electrocardiography. Some SSRI antidepressants such as fluoxetine and citalopram have shown to cause QT interval prolongation and ventricular arrhythmias including Torsade de Pointes. These drugs should be used with caution in patients with congenital QT syndrome, a previous personal or family history of QT prolongation, and ventricular arrhythmia. List of Drugs to be Avoided by Patients with Congenital Long QT Syndrome LQTS* updated July 2013 *This list is not comprehensive but is meant to be a practical list for those clinicians managing patients with LQTS in Canada. QT prolongation is a measure of delayed ventricular repolarisation, which can cause Torsades de Pointes, ventricular tachycardia, and sudden death. In elderly patients, patients with reduced hepatic function, patients who are CYP2C19 poor metabolisers, and patients taking CYPC19 inhibitors (eg, cimetidine and omeprazole), the maximum dose should not exceed 20 mg a day because these factors lead to increased blood levels of citalopram. Plaquenil and citalopram qt prolongation Evaluation of QTc prolongation and dosage effect with citalopram, Citalopram Disease Interactions - Adverse effects of hydroxychloroquine Patients should be screened for risk factors for QT prolongation before starting treatment with citalopram. Citalopram should be stopped and specialist advice sought in patients who have significant QTc prolongation QTc 500 ms or an increase of 60 ms unless there are compelling reasons to continue. Reminder Citalopram and QT Prolongation. List of Drugs to be Avoided by Patients with Congenital Long.. Plaquenil hydroxychloroquine – New Warnings. QT prolongation is an extended corrected QT QTc interval seen on an ECG at rest. 2 Because the QT interval is dependent on heart rate, the QTc interval is calculated to control for this factor. 2 QTc can be calculated by a variety of methods. 3 Definitions of QTc prolongation vary, but often this condition is described as a QTc interval of 440 ms. 2 Other definitions allow for a higher cutoff, such as 460 ms, in females. 3 The absence of drugs from these lists should not be considered an indication that they are free of risk of QT prolongation or torsades de pointes. Many medicines have not been tested for this risk in patients, especially those with congenital long QT syndrome. Cases of QT prolongation and ventricular arrhythmia, including Torsade de Pointes TdP, have been reported via the Yellow Card Scheme with citalopram and escitalopram, mainly in women, those with hypokalaemia, or in those with pre-existing QT prolongation or other cardiac diseases.