Methylene Blue is a dye that was synthesized in the late 1800s as an antimalarial drug. After the emergence of chloroquine its use loss favor partly due to unpopular side effects of temporarily turning the urine, other body fluids, and the sclera blue. Methylene blue is primarily known as a highly effective fast acting antidote for methemboglobinemia. Over the past few years, it has become an important therapeutic modality with expanding uses in cardiac surgery and critical care. As a potent inhibitor of nitric oxide mediated guanylate cyclase induced endothelium vascular smooth muscle relaxation, it has been shown to be effective in increasing arterial blood pressure and cardiac function in several clinical states, such as septic shock and calcium channel blocker poisoning.
BOTTOM LINE:
Methylene blue should be considered for treatment of refractory shock from calcium channel and beta blocker poisoning.
Clinical improvement in refractory hypotension and reduction of vasopressor dose has been described in several poisoning cases.
Recommended dose is 1–2 mg/kg injection with effects seen within 1 hour.
References
Methylene Blue Used in the Treatment of Refractory Shock Resulting From Drug Poisoning. Fisher J, et al. Clin Toxicol 2914 Jan;52:63-65.
Calicum channel antagonist and beta blocker overdose: antidotes and adjunct therapies. Graudins A, et al. British Journal of Clin Pharm. 2016;81(3):453-461.
