Primaquine is an 8-aminoquinoline which is given orally for the terminal prophylaxis and radical cure of vivax and ovale malaria. It is invariably given together with chloroquine. Primaquine causes haemolysis in susceptible individuals who suffer from glucose-6-phosphate dehydrogenase deficiency. Severe haemolytic reactions are seen among blacks and dark-skinned Caucasians such as Greeks, Sardinians, Sephardic Jews, and Iranians. Methaemoglobinaemia is fairly common with high doses of primaquine and can be severe in indi-viduals with NADH -methaemoglobin-reductase deficiency. Less serious adverse effects include abdominal distress, mild anaemia and leucocytosis.
Overdose is associated with granulocytopenia, agranulo-cytosis, hypertension, and arrhythmias. During the course of primaquine therapy, it is desirable to perform regular blood counts and urinalysis for haemoglobinuria.