Methaemoglobin results from the oxidation of ferrous to ferric iron in
the centre of the haem moeity 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 vivax and ovale malarias. Iatrogenic
methaemoglobinaemia may be a useful pharmacodynamic measure in
8-aminoquinoline drug and dose optimization.