Bansal T. Methylene blue - an emerging vasopressor. World J Clin Cases 2026; 14(13): 117947 [DOI: 10.12998/wjcc.v14.i13.117947]
Corresponding Author of This Article
Tapesh Bansal, Department of Intensive Care and Medicine, Paras Hospitals (former), C 43 Sushant Lok, Gurgaon 122002, Haryana, India. tapeshbansal1@gmail.com
Research Domain of This Article
Critical Care Medicine
Article-Type of This Article
Minireviews
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Tapesh Bansal, Department of Intensive Care and Medicine, Paras Hospitals (former), Gurgaon 122002, Haryana, India
Author contributions: Bansal T concept, write and edit the manuscript.
Conflict-of-interest statement: The author reports no relevant conflicts of interest for this article.
Corresponding author: Tapesh Bansal, Department of Intensive Care and Medicine, Paras Hospitals (former), C 43 Sushant Lok, Gurgaon 122002, Haryana, India. tapeshbansal1@gmail.com
Received: December 22, 2025 Revised: February 14, 2026 Accepted: April 1, 2026 Published online: May 6, 2026 Processing time: 125 Days and 11.8 Hours
Abstract
Methylene blue (MB) is being investigated as a useful adjunct in the management of vasoplegic and septic shock due to its targeted inhibition of the nitric oxide-soluble guanylate cyclase pathway. Early studies demonstrated improved systemic vascular resistance and reduced catecholamine requirements, laying the foundation for later randomized trials. The pivotal Ibarra-Estrada trial (2023) confirmed that early MB infusion decreases time to vasopressor discontinuation and increases vasopressor-free days. Subsequent data further support MB’s hemodynamic benefits in refractory distributive shock. Dosing regimens need to be refined, with cumulative doses of 2-4 mg/kg demonstrating optimal safety and efficacy currently. MB retains a favorable safety profile with minimal adverse effects when used within recommended limits. Additional applications include cardiac surgery vasoplegia, anaphylaxis, calcium channel blocker toxicity, ifosfamide encephalopathy, and reperfusion vasoplegia in liver transplantation. Overall, current evidence supports MB as a rational, mechanism-based adjunctive vasopressor in carefully selected patients with vasodilatory shock however a large randomised controlled trial and further evidence is needed to answer many lingering questions.
Core Tip: Methylene blue (MB) is a mechanistically rational adjunct vasopressor that targets nitric oxide (NO)-mediated vasodilation in septic shock. When used early and within safe cumulative dose (≤ 4 mg/kg), it consistently reduces vasopressor requirements without toxicity. Unlike non-selective NO synthase inhibitors, MB selectively modulates the NO-guanylate cyclase-cyclic guanosine monophosphate pathway by inhibiting only the inducible NO synthase isoform of NO synthase, preserving physiological constitutive functions. Current evidence supports its use as an adjunct rather than rescue therapy, pending results from ongoing randomized trials. In this narrative review we present the facts and data on MB with no fluff!
