Glucose-6-Phosphate Dehydrogenase Deficiency-Associated Hemolytic Anemia and Methemoglobinemia in a Patient Treated With Hydroxychloroquine in the Era of COVID-19.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymatic disorder of red blood cells worldwide. The severity of hemolytic anemia varies among individuals with G6PD deficiency, depending on the genetic variant in the G6PD gene; this makes the diagnosis of the condition more challenging in some cases. In this report, we present a case of severe hemolytic anemia and methemoglobinemia in a patient with G6PD deficiency who had been exposed to hydroxychloroquine prescribed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To the best of our knowledge and based on a literature search, this is one of the first case reports in the literature about hemolytic crisis and methemoglobinemia in a patient with critical illness due to severe coronavirus disease 2019 (COVID-19) who was exposed to hydroxychloroquine. It is critical for physicians and caregivers to recognize the effects of oxidative stressors such as hydroxychloroquine, particularly in this era of the COVID-19 pandemic and in regions with a high prevalence of G6PD deficiency, for the appropriate management of this unique subset of patients.