Efficacy of Magnesium Sulfate for Treatment of Ventricular Tachycardia in Amitriptyline Intoxication

Abstract

In our country, tricyclic antidepressants are usually present in most of the homes. Myocardial depression and ventricular arrhythmia are the severe side effects in tricyclic antidepressant overdose. A 4-year-old boy was brought to our hospital after taking 70 mg/kg of amitriptyline. On arrival, the patient was comatose (Glasgow Coma Score was 3), had a shallow breathing pattern with bradycardia (HR <30/min), and hypotension. He was intubated and resuscitated with multiple doses of adrenaline and sodium bicarbonate. He was infused with a bolus of 20 mg/kg of normal saline for hypotension. After 30 minutes, ventricular fibrillation was detected. Lidocaine and bicarbonate were not effective in converting the rhythm to normal, therefore, synchronized cardioversion was used. After cardioversion, the rhythm converted to ventricular tachycardia. Because ventricular tachycardia did not resolve, we administered a load of less than 2 g of magnesium sulfate for 30 minutes followed by a continuous infusion of 3 mg/min. After magnesium sulfate infusion, a normal cardiac rhythm was achieved. Magnesium sulfate is a very effective treatment in intractable arrhythmias caused by high-dose amitriptyline intoxication.

Can empirical hypertonic saline or sodium bicarbonate treatment prevent the development of cardiotoxicity during serious amitriptyline poisoning? Experimental research: cardiovascular topic

“…1 , 11 The most important cause of death is persistent hypotension resulting from myocardial depression due to arrhythmias. 3 , 5 , 10 , 12 , 13 …”

“…Various methods have been used to treat patients with severe cardiotoxicity due to amitriptyline overdose. These include serum alkalinisation with hypertonic NaHCO 3 20 or hyperventilation, 21 inotropic agents, 4 , 22 magnesium sulphate, 5 anti-arrhythmic drugs, 2 , 14 glucagon 12 haemoperfusion, 23 , 24 or lipid emulsion. 25 Although many studies have compared these treatment methods, no treatment has been shown to prevent or reduce the toxicity in patients who may potentially develop severe toxicity.…”

“…Sodium bicarbonate is the first choice in the treatment of TCA-induced cardiotoxicity. 4 , 5 There are several mechanism by which NaHCO 3 treatment may confer beneficial effects. It may increase serum sodium levels and reduce cardiac arrhythmias resulting from the inhibition of sodium channels.…”

“…1 , 3 Sodium bicarbonate (NaHCO 3 ) administration is the most widely accepted treatment to reduce amitriptyline-induced cardiotoxicity. 2 , 4 , 5 However, at an alkaline pH, the volume distribution of amitriptyline expands, and the elimination time is longer. Therefore, NaHCO 3 treatment is suggested only in the presence of cardiac findings.…”

Management of persistent wide QRS in flecainide overdose with magnesium sulphate

“…It has been used successfully in the treatment and prevention of various atrial and ventricular arrhythmias, torsades de pointes and in stabilising cardiac repolarisation in heart failure 9. Moreover, in cardiac toxicity (wide QRS, prolonged QT) due to tricyclic antidepressant overdose, which is largely mediated by class 1A antiarrhythmic effect (sodium channel blockade), magnesium has been found to be very effective in treating intractable arrhythmias 10. As a calcium-channel antagonist, magnesium sulphate may have the potential to worsen hypotension and atrioventricular block and its administration must be carefully considered.…”