What should you be most vigilant about when monitoring a patient who ingested 150 amitriptyline tablets?

When monitoring a patient who has ingested 150 amitriptyline tablets, being vigilant about cardiac monitoring is essential. Amitriptyline is a tricyclic antidepressant that can lead to significant cardiovascular effects, especially in overdose situations. These effects may include arrhythmias, prolonged QT interval, and potential for ventricular dysrhythmias, which can be life-threatening.

The drug's anticholinergic properties can contribute to tachycardia and other cardiac complications. Close cardiac monitoring will allow for the early detection of these potentially dangerous changes and facilitate timely medical intervention, which can significantly improve the patient's outcome.

While monitoring neurological status, respiratory function, and gastrointestinal symptoms is also important, the primary concern in the case of amitriptyline overdose revolves around the cardiovascular system, given the specific toxic effects associated with high doses of this medication.