Long QT syndrome due to Doxylamine overdose

Abstract

The list of medications known to induce QT prolongation is long. We report here a case of long QT syndrome (LQTS) caused by use of Doxylamine, which has previously only been reported once. The patient arrived to the emergency department after having ingested two bottles of Doxylamine (roughly 96 tablets) in a suicidal attempt and was noted to have seizure-like activity prior to arrival. Upon admission she was found to have severe rhabdomyolysis and significant QTc prolongation (>650 ms). Her clinical status improved over the course of hospitalization with supportive treatment that included intravenous fluids as well as electrolyte monitoring and replacement. Given the relative ubiquity of Doxylamine, the purpose of this article is to raise awareness of a unique adverse effect of a widely available medication.