Cardiovascular changes and plasma drug levels after amitriptyline overdose

Area of Science:

• Cardiology
• Clinical Toxicology
• Pharmacology

Background:

• Amitriptyline, a common tricyclic antidepressant (TCA), overdose can lead to significant cardiovascular toxicity.
• Understanding the specific electrocardiographic (ECG) and blood pressure (BP) changes associated with amitriptyline overdose is crucial for patient management.

Purpose of the Study:

• To retrospectively analyze ECG and BP parameters in patients following amitriptyline overdose.
• To investigate the correlation between plasma tricyclic antidepressant (TCAD) levels and observed cardiovascular effects.

Main Methods:

• Retrospective review of 17 patients with confirmed amitriptyline overdose.
• Analysis of electrocardiographic (ECG) findings including heart rate, QRS duration, PR interval, and QTc.
• Measurement of blood pressure (systolic and diastolic).
• Correlation analysis between plasma TCAD levels and clinical parameters.

Main Results:

• Significant increases in heart rate and QRS duration were observed in patients with available baseline EKGs.
• Sinus tachycardia (88%) and hypotension (53%) were the most common findings.
• Widened PR and QRS intervals were frequently noted post-overdose.
• Plasma TCAD levels correlated with PR and QRS durations and lowest observed systolic and diastolic blood pressure.
• The sole fatality exhibited the highest plasma TCAD level and ventricular arrhythmias.

Conclusions:

• Amitriptyline overdose commonly causes sinus tachycardia, hypotension, and ECG changes like widened PR and QRS intervals.
• Higher plasma TCAD levels are associated with more pronounced cardiovascular effects, including hypotension and ECG abnormalities.
• Close monitoring of ECG and BP is essential in managing amitriptyline overdose, with high TCAD levels indicating a poorer prognosis.