Open AccessBlue cures blue but be cautious
Author(s) -
Praveen Sikka,
VK Bindra,
Seema Kapoor,
V. Jain,
K. D. Saxena
Publication year - 2011
Publication title -
journal of pharmacy and bioallied sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.268
H-Index - 36
eISSN - 0976-4879
pISSN - 0975-7406
DOI - 10.4103/0975-7406.90112
Subject(s) - methemoglobin , methylene blue , methemoglobinemia , pentose phosphate pathway , nicotinamide adenine dinucleotide phosphate , chemistry , enzyme , dehydrogenase , hemoglobin , biochemistry , medicine , oxidase test , catalysis , glycolysis , photocatalysis
Methemoglobinemia is a disorder characterized by the presence of >1% methemoglobin (metHb) in the blood. Spontaneous formation of methemoglobin is normally counteracted by protective enzyme systems, for example, nicotinamide adenine dinucleotide phosphate (NADPH) methemoglobin reductase. Methemoglobinemia is treated with supplemental oxygen and methylene blue (1-2 mg/kg) administered slow intravenously, which acts by providing an artificial electron acceptor for NADPH methemoglobin reductase. But known or suspected glucose-6-phosphate dehydrogenase (G6PD) deficiency is a relative contraindication to the use of methylene blue because G6PD is the key enzyme in the formation of NADPH through pentose phosphate pathway and G6PD-deficient individuals generate insufficient NADPH to efficiently reduce methylene blue to leukomethylene blue, which is necessary for the activation of the NADPH-dependent methemoglobin reductase system. So, we should be careful using methylene blue in methemoglobinemia patient before G6PD levels.