Methylene blue in the critical care setting

Methylene blue (MB) is a versatile medicine with a long history of use in various medical applications, including dye, antiseptic, and treatment for methemoglobinemia. It has a role in vasoconstriction, methemoglobin reduction, inhibition of guanylate cyclase, and anti-inflammatory effects. We reviewed PubMed and Google Scholar literature for relevant studies on MB in intensive care unit (ICU). We created search criteria using a combination of free text words, including MB, critical care, intensive care, sepsis, surgery, pharmacokinetics, and pharmacodynamics. Relevant articles published in the English language were analyzed and incorporated. MB has been used in managing patients with refractory shock, including septic shock, vasoplegic shock, surgical patients, and some instances of drug-induced hypotension. In conclusion, MB in the ICU is a promising medication for sepsis and vasoplegic shock. Further research with randomized trials on its long-term safety in the ICU, time of initiation, dose, and duration is necessary.