The artemisinin derivatives are the most potent of all anti-malarial drugs. They reduce the infecting parasite biomass by approximately 10 000 fold per asexual lifecycle, which would protect vulnerable anti-malarials (those with a prolonged terminal elimination half life, those with a shallow concentration-effect relationship, and those in which a few base pair mutations confer a marked reduction in susceptibility¹⁶) against the development of resistance.

Artemisinin derivatives also reduce gametocyte carriage  by approximately 90%, reducing selection pressure to the spread of resistance, and reducing the transmission of malaria, and particularly the transmission of resistant strains of P falciparum.⁵ Recrudescent infections are associated with increased gametocyte carriage rates, which provide a powerful selection pressure for the spread of resistance.  With the possible exception of artemisinin derivatives, resistance of P falciparum to all available alternatives has been frequently described.

The efficacy and safety of artesunate plus SP is currently being evaluated in randomised controlled trials involving 4500 patients in sub Saharan Africa.  Results from the first study completed in the Gambia, where cure rate with SP monotherapy is 93%, showed that cure rate and parasite clearance was significantly higher in patients who received 3 days of artesunate PLUS a stat dose of SP when compared  to those who received SP monotherapy.  Gametocyte carriage was 68% following SP treatment in comparison to 21% following combination treatment (p = 0.001).

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