Methemoglobinemia in Acetaminophen Overdose and Glucose-6-phosphate Dehydrogenase Deficiency

Authors

Maelen Ignacio, PharmD, Thomas Jefferson University HospitalFollow
Colin Craft, MD, Thomas Jefferson University HospitalFollow
Fern M. Martin, MD, Thomas Jefferson University HospitalFollow
Cara McDaniel, PharmD, BCPS, Thomas Jefferson University HospitalFollow

Files

Description

Background:

• Methemoglobin (MetHb) is formed when the iron moiety of hemoglobin (Hgb) is oxidized from ferrous (Fe²⁺) to ferric (Fe³⁺) state à impaired O₂ delivery to tissues
• Acetaminophen Metabolism:

~90% is metabolized in liver via sulfation and glucuronidation

remainder is metabolized via CYP450 to a toxic oxidizing agent, N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified via glutathione¹

• Acute Acetaminophen Overdose:

saturates sulfation and glucuronidation pathways

depletes glutathione stores

leads to excess NAPQI à oxidative stress à methemoglobinemia¹

• MetHb Reduction Pathway:

cytochrome b5 reductase removes 95% to 99% of endogenous MetHb

nicotinamide adenine dinucleotide phosphate (NADPH

Publication Date

2-24-2016

Keywords

Methemoglobinemia in Acetaminophen Overdose and Glucose-6-phosphate Dehydrogenase Deficiency

Disciplines

Pharmacy and Pharmaceutical Sciences

Comments

Poster presented at: Society of Critical Care Medicine at Orange County California.

Recommended Citation

Ignacio, PharmD, Maelen; Craft, MD, Colin; Martin, MD, Fern M.; and McDaniel, PharmD, BCPS, Cara, "Methemoglobinemia in Acetaminophen Overdose and Glucose-6-phosphate Dehydrogenase Deficiency" (2016). College of Pharmacy Posters. 2.
https://jdc.jefferson.edu/pharmacyposters/2