Abstract
Baclofen overdose occasionally results in cardiac effects, but serious tachyarrhythmias have not been reported. We present the case of a 21-year-old man with an acute baclofen overdose who developed increased cardiac conduction times and a rapid supraventricular tachyarrhythmia which required medical intervention. Acute baclofen toxicity can result in the development of tachyarrhythmias and cardiac monitoring is warranted in acute overdose states.