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

Effect of the selective mitochondrial KATP channel opener nicorandil on the QT prolongation and myocardial damage induced by amitriptyline in rats

OBJECTIVES

The aim of this study is to evaluate the protective effect of nicorandil, a selective mitochondrial KATP channel opener, on QT prolongation and myocardial damage induced by amitriptyline.

METHODS

The dose of amitriptyline (intraperitoneal, i.p.) that prolong the QT interval was found 75 mg/kg. Rats were randomized into five groups the control group, amitriptyline group, nicorandil (selective mitochondrial KATP channel opener, 3 mg/kg i.p.) + amitriptyline group, 5-hdyroxydecanoate (5-HD, selective mitochondrial KATP channel blocker, 10 mg/kg i.p.) + amitriptyline group and 5-HD + nicorandil + amitriptyline group. Cardiac parameters, biochemical and histomorphological/immunohistochemical examinations were evaluated. p < 0.05 was accepted as statistically significant.

KEY FINDINGS

Amitriptyline caused statistically significant prolongation of QRS duration, QT interval and QTc interval (p < 0.05). It also caused changes in tissue oxidant (increase in malondialdehyde)/anti-oxidant (decrease in glutathione peroxidase) parameters (p < 0.05), myocardial damage and apoptosis (p < 0.01 and p < 0.001). While nicorandil administration prevented amitriptyline-induced QRS, QT, QTc prolongation (p < 0.05), myocardial damage and apoptosis (p < 0.05), it did not affect the changes in oxidative parameters (p > 0.05).

CONCLUSIONS

Our results suggest that nicorandil, a selective mitochondrial KATP channel opener, plays a protective role in amitriptyline-induced QT prolongation and myocardial damage. Mitochondrial KATP channel opening and anti-apoptotic effects may play a role in the cardioprotective effect of nicorandil.

Potential Impact of 3% Hypertonic Saline Infusion on Tramadol Poisoning-Induced Electrocardiogram Changes; a Randomized Clinical Trial

Introduction

Tramadol is a synthetic analgesic with weak mu-opioid receptor agonist activity. Tramadol overdose is associated with adverse cardiac effects due to inhibiting cardiac Na+ and K+ channels. This study aimed to investigate the potential ameliorative role of 3% hypertonic saline on the electrocardiogram (ECG) changes in patients presenting with tramadol poisoning.

Methods

This was a single-center, controlled, randomized, single-blind clinical trial. Patients were randomized into the case (received hypertonic saline) and control (received placebo) groups. ECG was obtained twice in each group (upon arrival and following the intervention). Response to therapeutic interventions was evaluated using Wilcoxon Signed Ranks Test.

Results

A total of 76 patients were included. The mean age of patients was 24.88 ± 4.29 years, and 62 (81.6%) were male. The mean ingested dose of tramadol was 1673.68 ± 608.85 (range: 550-2750) mg. The number needed to treat and the absolute risk reduction of 3% hypertonic saline in the treatment of wide QRS were 1 (95% CI: 1.00 - 1.00) and 100%, respectively. In the treatment of long QTc, these measures were 1.9 (95%CI: 1.2 - 4.5) and 53.85% (95%CI: 22.00 - 85.69), respectively.

Conclusion

Given that hypertonic saline infusion can significantly ameliorate tramadol-mediated ECG changes, including QRS prolongation and QT lengthening, it can be regarded as a potential therapeutic strategy to prevent the development of life-threatening ventricular arrhythmias caused by tramadol toxicity.

A Case of Amitriptyline-induced Myocarditis

Amitriptyline is a widely prescribed tricyclic antidepressant (TCA) with a very concerning cardiotoxicity profile, but it is one that has not been discussed much in literature. Here, we present a case of amitriptyline toxicity presenting as myocarditis with pericardial involvement. A 21-year-old male with no previous cardiac history presented to the emergency department (ED) with a decreased level of consciousness after an amitriptyline overdose as a suicidal attempt. For concerns with airway protection, the patient was intubated and subsequently admitted to the intensive care unit (ICU). An electrocardiogram (EKG) showed sinus tachycardia, prolonged QRS complex, prolonged QTc interval, and nonspecific ST-T wave changes. Intravenous fluid resuscitation and sodium bicarbonate were administered with a target blood pH of 7.5 to 7.55. Two days later, the patient was taken off mechanical ventilation and improved clinically. However, troponin levels began to rise with a peak level of 4.08 µg/L. He then began having fevers, elevated white blood cell counts (WBCs), and elevated inflammatory markers. Transthoracic echo (TTE) revealed an ejection fraction (EF) of 45%-50%, no wall segment motion abnormalities, and a mild-to-moderate pericardial effusion. Cardiac magnetic resonance (CMR) was done, which revealed changes indicative of acute myocarditis, moderate pericardial effusion, a calculated EF of 45% with a moderate left ventricular dilation, and no coronary artery stenosis or anomalous coronary artery origin. Given the patient’s age, the absence of cardiac risk factors, and the presence of an amitriptyline overdose along with his EKG, TTE, and CMR findings, we hypothesize that this myocarditis with pericardial involvement is due to amitriptyline-induced direct toxicity.