Case Report on Metaclopromide Induced Methemoglobinemia in a CKD Patient

Methemoglobin is an oxidized metabolite of hemoglobin, and its normal physiologic level is (< 1%). Abnormality occurs as methemoglobin levels increase. Methemoglobinemia occurs when red blood cells (RBCs) contain methemoglobin at levels higher than 1%. This may be from congenital causes, increased synthesis, or decreased clearance, and acquired causes. Increased levels may also result from exposure to toxins that acutely affect redox reactions, increasing methemoglobin levels. A 49 year old male a known chronic kidney disease patient, whose blood sample sent for biochemical analysis showed dark brown (chocolate brown) serum. On analysis the patient found to have methemoglobinemia. His arterial methemoglobin level of 22%. Going into detailed history he was found to be using Inj. metaclopromide for gastroesophageal reflux, though it is rarely reported to cause methemoglobinemia in adults compared to infants. He was treated with dialysis, cautious use of methylene blue and his clinical symptoms improved and the methemoglobin level returned to normal within 24 hours. By analysing this case we discuss the clinical features, diagnosis, cause and treatment of acquired methemoglobinemia induced by metoclopramide.