Three days after starting a new drug for malaria prophylaxis, a 19-year-old college student comes to the physician because of dark-colored urine and fatigue. He has not had any fever, dysuria, or abdominal pain. He has no history of serious illness. Physical examination shows scleral icterus. Laboratory studies show a hemoglobin of 9.7 g/dL and serum lactate dehydrogenase of 284 U/L. Peripheral blood smear shows poikilocytes with bite-shaped irregularities. Which of the following drugs has the patient most likely been taking?

Question

Quizplus · Accepted Answer

Eductional Objective: Primaquine is an antimalarial used for malaria prophylaxis that causes oxidative stress in RBCs and can precipitate hemolytic anemia in individuals with G6PD deficiency, as seen in this case. Bite cells and Heinz bodies are characteristic blood smear findings. Primaquine is contraindicated in patients with known G6PD deficiency.

Three Days After Starting a New Drug for Malaria Prophylaxis