Methylene Blue for the Treatment of Refractory Hypotension in Polysubstance Overdose.

Methylene blue is commonly used for methemoglobinemia and vasoplegia following coronary artery bypass procedures but has recently been investigated as a treatment for refractory hypotension. One such cause of refractory hypotension is overdose of calcium channel blocker medications. This case presents a patient with polysubstance overdose and refractory hypotension that improved with methylene blue infusion. This 67-year-old female presented to the ED following an intentional toxic ingestion of multiple substances, including metoprolol, amlodipine, mirtazapine, pantoprazole, quetiapine, levetiracetam, melatonin, and levothyroxine. The patient's hypotension remained unresponsive to fluids, calcium chloride, calcium gluconate, and multiple pressure support medications, including norepinephrine, epinephrine, vasopressin, and phenylephrine. Insulin and dextrose, as well as methylene blue were initiated for severe refractory hypotension unresponsive to other measures. Methylene blue inhibits guanylate cyclase, which decreases the production of cyclic guanosine monophosphate. This, in turn, inhibits vascular smooth muscle relaxation and can be an effective method for refractory hypotension. Therefore, methylene blue can be used for the treatment of refractory vasoplegia unresponsive to other methods.