Clinical problems associated with the use of primaquine as a tissue schizontocidal and gametocytocidal drug.

Clinically important side-effects of primaquine are reviewed. These include gastrointestinal disturbances, methaemoglobinaemia, acute intravascular haemolysis in individuals deficient in glucose-6-phosphate dehydrogenase (G6PD), and possibly immunosuppression through inhibition of lymphocyte proliferation. Dosages of 30 or 45 mg (base) of primaquine, given at weekly intervals, are suitable for patients with G6PD deficiency. If possible, primaquine should not be administered until the acute symptoms of the malaria attack have been brought under control.