This paper has dealth with evaluation of an antimalarial agent, CI-564, a 1:1 mixture of cycloguanil pamoate (CI-501) and 4,4′-diacetyl-aminodiphenylsulfone (CI-556) against three different multiresistant strains of falciparum malaria, Malayan III, Malayan IV, and Thai II.
The CI-501 component, given intramuscularly, at a dosage of 5 mg per kg of body weight, had no protective effect against sporozoite-induced infections. CI-564, also given intramuscularly, at a dosage of 5 to 7.5 mg per kg of body weight, protected eight of nine volunteers exposed to bites of mosquitoes infected with one of the three multiresistant strains, but protection was lost in less than 70 days. When used as a therapeutic agent, radical cures were realized in only 10 of 15 infections. As a consequence of the above, we believe that CI-564 has limited possibilities as an antimalarial agent.
Present address: Department of Pharmacology, Louisiana State University School of Medicine, 1542 Tulane Avenue, New Orleans, Louisiana 70112.