The chemotherapy of rodent malaria, XXII. The value of drug-resistant strains of P. berghei in screening for blood schizontocidal activity.

Data are provided on the activity of a variety of antimalarial drugs against drug-sensitive and drug-resistant lines of Plasmodium berghei in albino mice. Parallel data for the response of the drug-sensitive parasites to these compounds in vitro indicate whether the drugs have a chloroquine-like or quinine-like type of action, or neither. The value of this test system for drug evaluation is debated. It is concluded that the in vivo tests do provide a valuable indication of the potential use of a compound against drug-resistant malaria parasites of man. The tests may also provide a good indication of the future value of new compounds against strains of parasites that are already resistant to chloroquine. Where necessary, steps should be taken to protect promising new compounds.