Methylene blue reverses recalcitrant shock in β-blocker and calcium channel blocker overdose

Abstract

SUMMARY β-blocker and calcium channel blocker toxicity generally present with bradycardia and hypotension. A 69-year-old woman presented after a suicide attempt with a β-blocker and calcium channel blocker overdose. Her blood pressure was 69/35 mm Hg and her HR was in the 40s. She was treated with calcium chloride, glucagon, a dextrose-insulin infusion and three vasopressors, but remained hypotensive. She suffered two cardiac arrests and required a transvenous pacemaker. When all interventions failed, she was started on a methylene blue infusion for refractory vasodilatory shock which resulted in a dramatic improvement in her blood pressure. The patient was successfully weaned off all vasopressors and from mechanical ventilation without any end-organ damage. BACKGROUND

H2S induced coma and cardiogenic shock in the rat: Effects of phenothiazinium chromophores

“…Both these agents share the same inhibitory effect on mitochondrial function as H 2 S. Finally, MB may have antagonized the blocking effects of H 2 S on calcium channels. 75,76 …”

Improvement in Hemodynamics After Methylene Blue Administration in Drug-Induced Vasodilatory Shock: A Case Report

“…No apparent adverse effects were noted in this case nor have they been reported in previous cases in which methylene blue was used for drug-induced vasodilatory shock [8,10]. Risks from use of methylene blue are mainly described in case reports in which methylene blue has been used for other indications.…”

“…Existing case reports for use of methylene blue in vasodilatory drug-induced shock describe improvements in clinical parameters of blood pressure, pulse rate, and acidemia shortly after (∼1 h) administration of methylene blue for shock recalcitrant to other interventions including high-dose insulin, vasopressors, calcium, and transvenous pacing [8][9][10]12]. Invasive hemodynamic data is well documented in cases of refractory vasodilatory shock treated with methylene blue in sepsis and coronary artery bypass surgery [4,5,7].…”

“…Increases in systemic vascular resistance and mean arterial pressure have been consistently described following methylene blue administration for shock due to non-poisoning causes, including vasoplegic syndrome after coronary artery bypass surgery [4] and sepsis [5][6][7]. Methylene blue, from a mechanistic standpoint, is an attractive therapy for drug-induced vasodilatory shock, though published literature includes only a small number of human case reports and animal studies [8][9][10][11]. The human reports primarily describe the successful use of methylene blue in vasodilatory shock caused by dihydropyridine calcium channel blockers, though successful treatment of shock from quetiapine [9] and valsartan [12] with methylene blue has also been described.…”

Therapeutic Approach to the Critically Poisoned Patient

“…In a single case report, methylene blue was successfully used in a mixed atenolol and amlodipine ingestion [126]. Amlodipine stimulates the release of nitric oxide, thereby causing vasodilation and worsening hypotension.…”