Primaquine Disease Interactions

Hemolysis, hemolytic anemia, and methemoglobinemia have been reported during use of primaquine in patients with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency or nicotinamide adenine dinucleotide (NADH)-methemoglobin reductase deficiency. Therapy with primaquine should be administered cautiously in these patients. Since large doses of primaquine may increase the risk of hemolytic reactions, the recommended dosage (15 mg base daily for 14 days in adults) should not be exceeded. Close monitoring is recommended if primaquine is prescribed to patients who have shown a previous idiosyncrasy to primaquine or that have family or personal history of favism. Blood cell counts and hemoglobin determinations should be performed regularly. Primaquine therapy should be discontinued immediately if signs suggestive of hemolytic anemia occur, such as marked darkening of the urine or sudden decrease in hemoglobin concentration or erythrocytic count.

The use of primaquine is contraindicated in acutely ill patients suffering from systemic disease manifested by tendency to granulocytopenia, such as rheumatoid arthritis and lupus erythematosus. Primaquine has been reported to cause hematologic toxicity such as bone marrow depression, anemia, and leukopenia. Therapy with primaquine should be administered cautiously in patients with preexisting bone marrow depression or leukopenia. Since large doses of primaquine may increase the risk of leukopenia, the recommended dosage (15 mg base daily for 14 days in adults) should not be exceeded. Close monitoring is recommended if primaquine is prescribed to patients who have shown a previous idiosyncrasy to primaquine as manifested by leukopenia, hemolytic anemia, or methemoglobinemia. Blood cell counts should be performed regularly. Primaquine therapy should be discontinued immediately if there is a sudden decrease in leukocyte count.