G6pd Deficiency

A patient develops pallor, jaundice, fatigue, and cola-coloured urine several days after starting an antibiotic. The immediate question is not simply whether the haemoglobin is low; it is whether an oxidant exposure has triggered haemolysis in red cells that cannot defend themselves against reactive oxygen species. G6PD deficiency is usually quiet between episodes. The clinical pattern appears when infection, fava beans, or a medication creates oxidative stress. The practical sequence is to identify and remove the trigger, support the patient while haemolysis settles, and avoid being falsely reassured by a normal enzyme result obtained during the crisis. Medication and food education then prevent the next episode. In a newborn, the same disorder may present instead as an abrupt, severe rise in bilirubin, so unexplained or persistent jaundice requires a lower threshold for investigation.