The Drug-Induced Respiratory Disease Website
Known since the 1940s (PMID 18883450). Comprehensive list of causal drugs and chemicals available at PMID 1564446. Methemoglobin is the oxidized (Fe3+) species of hemoglobin (Fe2+). Patients present with slate-grey cyanosis, low SpO2, normal SaO2 and PaO2. Normally, methemoglobin is <1%. Levels above 40% can be life-threatening, producing pulmonary edema, cardiovascular collapse (PMID 17122537) CNS disturbances and death. Management includes i.v. methylene blue. A possible rebound increase in MeHb upon treatment requires close monitoring. Excess methylene blue can also produce methemoglobinemia. Guidelines: PMID 34467556.
Publications
Blue cures blue but be cautious.
Journal of pharmacy & bioallied sciences 2011 Oct;3;543-5 — 2011 Oct — 543-5
Methylene blue-induced methemoglobinemia during cardiopulmonary bypass? A case report and literature review.
The journal of extra-corporeal technology 2008 Sep;40;206-14 — 2008 Sep — 206-14