Ascorbic Acid for the Treatment of Methemoglobinemia

Abstract

The purpose of reporting this series of patients is to illustrate the role of ascorbic acid in the treatment of severe acquired methemoglobinemia (metHb), especially when methylene blue is not available. Medical records of affected patients were reviewed to collect history of exposures, food ingestion, physical examination, pulse oximetry, blood gas, and co-oximetry results, and outcomes. Five cases of acquired metHb are presented here, all of whom received treatment with ascorbic acid and fully recovered after 24 hours of treatment. Our series emphasizes that ascorbic acid is an effective alternative in the management of acquired metHb if methylene blue is unavailable and suggests that ascorbic acid infusion may be indicated in patients with glucose-6-phosphatase dehydrogenase deficiency.

Therapeutic effect of ascorbic acid on dapsone-induced methemoglobinemia in rats

“…When methylene blue is unavailable, ascorbic acid can be used, although multiple doses are required, and its response is less effective. As an alternative to methylene blue, ascorbic acid can be a therapeutic agent for methemoglobinemia in some cases [ 19 - 21 , 26 ]. Ascorbic acid, the most investigated antioxidant and free radical scavenger in the literature, reduces methemoglobin directly [ 27 , 28 ].…”

“…In this case, DDS induced toxic methemoglobinemia, and high doses of ascorbic acid (i.e., 10 g of ascorbic acid every 6 hours) were administered until approximately 54 hours after emergency department presentation. Another case series of ascorbic acid treatment for methemoglobinemia was reported by Rino et al [ 26 ] The authors described five cases of children with acquired methemoglobinemia; one patient became symptomatic after treatment with DDS for pemphigus, and three patients developed symptoms after ingestion of either food or water suspected of containing high levels of nitrites. The methemoglobin levels of these patients ranged from 6.4% to 43%.…”

“…At 120 minutes, the methemoglobin concentration of the ascorbic acid group was not significantly different from that of the control group, whereas the methylene blue group showed a more marked difference. In actual clinical cases, because the therapeutic response to ascorbic acid is less marked, repeated doses of intravenous ascorbic acid or an oral preparation have been prescribed, whereas we administered a single intravenous dose of ascorbic acid [ 20 , 26 ]. Furthermore, we administered 15 mg/kg of ascorbic acid in doses determined in a pilot study.…”

Not the Typical Pneumonia: An Unusual Case of Rasburicase-induced Methomoglobinemia

“…Furthermore, methylene blue has oxidant potential which may induce hemolysis in G6PD deficient patients [ 15 ]. In these patients, ascorbic acid is recommended [ 16 ]. Ascorbic acid is slow in onset and requires up to 24 hours and therefore is a poor choice in such emergencies [ 16 ].…”

“…In these patients, ascorbic acid is recommended [ 16 ]. Ascorbic acid is slow in onset and requires up to 24 hours and therefore is a poor choice in such emergencies [ 16 ]. Reviewing the literature, only one case was successfully managed using ascorbic acid alone [ 9 ].…”