TCA overdose may occur by accident or purposefully in an attempt to cause death.[2] The toxic dose depends on the specific TCA.[2] Most are non-toxic at less than 5 mg/kg except for desipramine, nortriptyline, and trimipramine, which are generally non-toxic at less than 2.5 mg/kg.[5][2] In small children one or two pills can be fatal.[6] An electrocardiogram (ECG) should be included in the assessment when there is concern of an overdose.[2]