Amitriptyline is a member of the tricyclic antidepressant (TCA) drug group and can cause electrocardiographic (ECG) changes. Some of these changes include the prolongation of the QRS and QTc intervals, increment of R/s ratio on derivation aVR besides of arrhythmias such as supraventricular tachycardia (SVT) and ventricular tachycardia (VT) on overdose. Here, we present a case concerning a QRS interval prolongation caused by the intentional use of high doses of amitriptyline and treated with an intravenous lipid emulsion (ILE) infusion.