It is an electrical disturbance which can be seen on an electrocardiogram (ECG). Excessive QT prolongation can trigger tachycardias such as Torsades de Pointes (Td P). Side effects discontinuing plaquenil Hydroxychloroquine plaquenil wikipedia Seroqul and chloroquin Drug-induced QT interval prolongation Experience with both QT/QTc interval-prolonging medicines and the congenital long QT syndrome suggests • A QT/QTc interval 500ms is associated with a higher risk of TdP and sudden cardiac death; • Among drugs with QT/QTc interval-prolonging potential, Several drugs have been withdrawn from the U. S. market or have received black box warnings due to their potential to cause QT interval prolongation that leads to fatal ventricular arrhythmias and sudden cardiac death. 1,2 Predicting the risks involved with most of these drugs is difficult, since they are often structurally and pharmacologically unrelated. Although it is convenient to think of QT prolongation as occurring because of either congenital or acquired abnormalities, the phenomenon probably most often involves a gene-environment interaction. Pure congenital prolongation characterized by lifelong, ambient QT prolongation is rare but does carry a high risk of sudden death. On an EKG, the QT interval represents the summation of action potentials in cardiac muscle cells, which can be caused by an increase in inward current through sodium or calcium channels, or a decrease in outward current through potassium channels. QT prolongation is an established side effect of anti-arrhythmic medicines, but can also be caused by a wide range of non-cardiac medicines, including antibiotics, antihistamines, opioid analgesics and complementary medicines. Chloroquine qt prolongation Risk assessment of drug-induced QT prolongation, Drug-Induced QT Prolongation - U. S. Pharmacist Plaquenil anxiety Chloroquine is associated with an increased risk of QT prolongation and torsade de pointes TdP; fatalities have been reported. The risk of QT prolongation is increased with higher chloroquine doses. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Chloroquine Phosphate chloroquine phosphate dose.. What Clinicians Should Know About the QT Interval Cardiology JAMA.. Drug-induced QT prolongation - Wikipedia. Acute HCQ poisoning has been reported to cause a prolonged QT interval, hypokalaemia and a prolonged QRS complex. RA itself is an independent risk factor for cardiovascular CV disease and a recent study has shown that patients are 40% more likely to develop atrial fibrillation. Before using chloroquine, tell your doctor or pharmacist if you have any of the following conditions certain heart problems heart failure, slow heartbeat, QT prolongation in the EKG, family history of certain heart problems QT prolongation in the EKG, sudden cardiac death. QT prolongation, a surrogate marker for the risk of developing TdP, is an established side effect of Class I and Class III anti-arrhythmic medicines. It is also a rare side effect of a wide range of non-cardiac medicines including some antibiotics, antihistamines, opioid analgesics and complementary medicines. What is QT prolongation?