A case report describing myocardial ischaemia as a side effect of carbamazepine overdose

Abstract

Background: Overdoses of carbamazepine may occur due to various reasons. The summary of product characteristics of carbamazepine includes information about the possibility of side effects after taking this drug. However, the symptoms described do not include coronary vasospasm, which occurred in the case described. Making such a diagnosis is a key element in therapeutic management, as it changes further clinical decisions.

Case summary: A 46-year-old patient was admitted to the hospital for disorders of consciousness following an overdose of carbamazepine. On the second day, the patient exhibited respiratory distress. Subsequently, the patient was transferred to the intensive care unit, intubated, and placed on mechanical ventilation. On the same day, the patient experienced recurrent cardiac arrhythmias in the form of pulseless ventricular tachycardia and ventricular fibrillation; the patient was resuscitated and defibrillated eight times. Due to a rapid decline in cardiac output coupled with persistent electrocardiographic changes and haemodynamic instability, the patient underwent urgent coronary angiography. The procedure revealed a spasm in the initial segment of the circumflex branch of the left coronary artery, which subsequently resolved following nitroglycerin administration. Subsequent to the implementation of this therapeutic approach, a reduction in the demand for norepinephrine and dobutamine was achieved. In the following days, the patient's general condition improved. The patient was discharged home while maintaining full cognitive capacity and cardiovascular and respiratory fitness.

Discussion: In the case described, the expeditious performance of a cardiological diagnostic evaluation played a pivotal role in achieving therapeutic success, enabling the prompt initiation of appropriate treatment.

Keywords: Arrhythmia; Carbamazepine; Case report; Coronary artery spasm; Intoxication.

Figure 1

Electrocardiogram performed before sudden cardiac arrest occurred.

Figure 2

Electrocardiogram performed immediately after return of spontaneous circulation, before coronary angiography.

Figure 3

Electrocardiogram performed the day after coronary angiography. The patient received intravenous nitroglycerin by continuous infusion.