Prolongation of the QT interval under treatment with hydroxychloroquine in a patient with systemic lupus erythematosus: A case report

Hydroxychloroquine (HCQ) is an antimalarial used in the treatment of patients with systemic lupus erythematosus (SLE). HCQ has a good safety profile and favorable results in terms of controlling clinical manifestations in SLE. In addition to known side effects such as retinal toxicity and neuromusculopathy, prolongation of the QT interval is mentioned in multiple studies. The QT interval can be prolonged due to comorbidities, medication or dyselectrolytemia. QT corrected interval (QTc) durations greater than 470ms for women and greater than 450ms for men are prolonged according to the European Medicines Agency (EMA). QTc interval duration greater than 500ms predisposes to Torsades des Pointes (TdP), a cause of sudden death. The aim of the present work was to present a case of a SLE patient who was treated with HCQ for over 20 years and who showed a prolongation of the QT interval on the electrocardiogram (ECG).