Letter to the Editor

First report of metronidazole-induced QT interval prolongation

This chapter explores the potential for antimicrobial drugs to cause QT interval prolongation and torsades de pointes (TdP). Common mechanisms include inhibition of the rapid component of the delayed rectifier potassium current (I_Kr) as well as pharmacokinetic and pharmacodynamic drug-drug interactions. Many antimicrobials agents have the potential to cause TdP and electrocardiogram (ECG) monitoring is recommended in some cases. Attention should also be paid to other risk factors for proarrhythmia.

This chapter discusses the adverse effects of antiprotozoal drugs, such as antimalarial drugs 4-aminoquinolines (chloroquine and congeners), pyrimethamine, congeners, quinine, and congeners. Amodiaquine + artesunate and artesunate + lumefantrine are currently the preferred regimens for the treatment of malaria in most of sub-Saharan Africa. However, there are limited data on their safety and efficacy in human immunodeficiency virus (HIV)-infected populations. Ina study, the authors concluded that although artesunate + amodiaquine is efficacious in the HIV-positive children, the high risk of neutropenia, especially in those receiving concurrent antiretroviral drugs, necessitates evaluation of alternative regimens. Cases of fixed skin eruptions because of quinine in tonic water have been reported, fixed skin eruptions have been reported with therapeutic quinine but rarely with quinine in drinks. Metronidazole, a drugs used in the treatment of other protozoal infections, is associated with acute reversible cerebellar lesions and thrombotic thrombocytopenic purpura.

El síndrome de QT largo adquirido es una entidad poco frecuente, pero su diagnóstico es de vital importancia por el riesgo que tiene de desencadenar una Torsión de puntas y muerte súbita. Es una patología que se puede producir por diferentes causas en pacientes que tienen una susceptibilidad genética. Estos pacientes habitualmente presentan un intervalo QT normal de base. Algunos de los factores que pueden alargar el intervalo QT son fármacos de uso habitual, como son antibióticos o algunos de los fármacos empleados en la anestesia general. Por todo ello, es fundamental diagnosticarlo y conocer el manejo anestésico de este tipo de pacientes, así como la prevención y el tratamiento de la complicación más temida que puede dar, que es la fibrilación ventricular. Presentamos el caso de un paciente sin antecedentes de interés que en el contexto del perioperatorio urgente de un absceso periamigdalino presentó un síndrome de QT largo adquirido con varios episodios de Torsión de puntas y parada cardiorrespiratoria.

Acquired long QT syndrome is a rare condition whose diagnosis is of vital importance given the risk of torsade de pointes and sudden death. This syndrome may be triggered by various events in patients with a genetic predisposition. Patients usually have a normal baseline QT interval. Some of the factors that may prolong the interval are exposure to common drugs such as antibiotics or agents used for general anesthesia. Diagnosis of the condition is essential, as is knowledge of how to manage anesthesia and prevent ventricular fibrillation, which is the most feared complication. We report the case of a man with no relevant medical history who underwent emergency surgery for a peritonsillar abscess. The patient developed long QT syndrome, with several episodes of torsade de pointes and cardiorespiratory arrest.