Successful management of methemoglobinemia with oral ascorbic acid: Dual case reports

Abstract Methemoglobinemia is a rare blood disorder characterized by elevated levels of methemoglobin (MetHb), leading to a reduced capacity of red blood cells to carry oxygen, resulting in functional hypoxia and cyanosis. This article presents two unique cases of methemoglobinemia successfully managed with oral ascorbic acid, showcasing an alternative treatment approach for mild cases. Both patients, an adult male and female with unexplained, persistent desaturation and central cyanosis, were diagnosed with congenital methemoglobinemia through arterial co-oximetry, revealing elevated MetHb levels (20.6% and 17.3%, respectively). Traditional therapy for methemoglobinemia involves methylene blue, which carries risks, particularly in glucose-6-phosphate dehydrogenase (G6PD) deficiency cases. In these instances, we opted for oral ascorbic acid as a safer alternative, resulting in substantial reductions in MetHb levels and symptomatic improvement within 2 weeks. This case series underscores the potential of ascorbic acid for managing nonsevere methemoglobinemia, especially in patients where G6PD status is unknown or in settings with limited resources. The key takeaway message is that ascorbic acid can be an effective, low-risk therapeutic option for managing mild cases of methemoglobinemia, expanding treatment options in specific clinical contexts.