Rapid reversal of vasoplegia with methylene blue in calcium channel blocker poisoning.

INTRODUCTION

Calcium channel blockers (CCBs) are a potent class of medications that exert its action by blocking 'L-type' calcium channels. CCB overdose can be fatal even with appropriate and aggressive therapy. Death ensues from heart block, myocardial suppression, vasoplegia, and shock. Early use of methylene blue (MB) might provide additional means to improve outcomes.

CASE PRESENTATION

A 25-year-old female presented after an attempted suicide. The patient ingested a substantial amount of diltiazem, promethazine, and trazodone. Seven hours following the ingestion, she became profoundly vasoplegic and hypotensive. Despite guideline-based therapy and high doses of vasopressors, she suffered from worsening lactic acidosis and multiorgan failure. Administration of an intravenous bolus dose of MB resulted in a rapid and sustained improvement of vasoplegia, and the patient subsequently went on to make a complete recovery.

DISCUSSION

In addition to calcium channel blockade, CCBs cause vascular smooth muscle relaxation by the production of nitric oxide (NO). In cases of overdose, NO production can be significant. MB is a safe and inexpensive medication with the potential to reverse NO-mediated vasoplegia that is responsible for CCB induced shock state. In parts of the world where access to advanced medical care is not readily available, early use of MB might have a significant role in the management of CCB overdose.