Methaemoglobinaemia and the radical curative efficacy of 8-aminoquinoline antimalarials.

Methaemoglobin results from the oxidation of ferrous to ferric iron in the centre of the haem moiety of haemoglobin. The production of dose-dependent methaemoglobinaemia by 8-aminoquinoline antimalarial drugs appears to be associated with, but is not directly linked to, therapeutic efficacy against latent Plasmodium vivax and Plasmodium ovale malarias (radical cure). Iatrogenic methaemoglobinaemia may be a useful pharmacodynamic measure in 8-aminoquinoline drug and dose optimization.