The repository antimalarial cycloguanil pamoate, known as CI-501 (Camolar®) was administered to 173 subjects living on a malarious island near Rabaul, New Guinea. It was given as a deep intragluteal injection at a dosage of 9.3 to 11.0 mg per kg body weight to children and at a total dose of 350 mg to subjects weighing over 32 kg-Concurrently, a single oral dose of a 4-aminoquinoline (amodiaquine) was given on the basis of 600 mg base for adults and proportionately less for children.
The drug was well accepted by the community and there were no observed systemic side-effects. Many subjects showed some local injection site reactions but these were mostly mild in nature and subsided quickly.
Asexual forms of both Plasmodium falciparum and P. vivax disappeared within 72 hours of drug administration. High attendance was maintained at the monthly follow-up blood surveys. Patent infections of P. vivax first reappeared on day 90, but P. falciparum did not reappear until 150 days after treatment.
The entomological observations, as well as the blood surveys conducted on the untreated observation group, showed that transmission of both species occurred throughout the study period.
The results from this area indicate that the combined administration of cycloguanil pamoate and a 4-aminoquinoline provided better protection against P. falciparum than against P. vivax. The duration of protection afforded by CI-501 against P. falciparum makes it conceivable that this species could be eliminated from certain isolated communities provided all the inhabitants receive the drug.