Abstract
An accurate system with stringent criteria was established to test antimalarial drugs and drug combinations against P. berghei in mice. Minimum effective doses for a number of antimalarial drugs were determined when used in this system. Considerable potentiation of the activity of pyrimethamine and to a somewhat less extent of proguanil by dapsone was demonstrated. The need to extend studies of these combinations to the parasites of human malaria is discussed in terms of establishing a safe chemoprophylactic regime in the presence of drug-resistant strains of parasites.