However, in areas of chloroquine resistance an appropriate ACT (but not artesunate-sulphadoxine/pyrimethamine) combined with primaquine is to be used, particularly where ACT is first line therapy for P. falciparum, although primaquine is counter-indicated with severe glucose-6-phosphate dehydrogenase (G6PD) deficiency. Here, G6PD is linked to G6PD deficiency.