Efficacy of intramuscular amopyroquin for treatment of Plasmodium falciparum malaria in the Gabon Republic.

The efficacy of a 12-mg/kg (of body weight) intramuscular amopyroquin (ApQ) regimen (two successive 6-mg/kg injections at a 24-h interval), previously established from kinetic studies on healthy volunteers and multicenter studies on patients with malaria, was investigated in 152 patients (children and adults) in Gabon with Plasmodium falciparum malaria. All children in the present study (ages, 1 to 14 years) showed higher degrees of parasitemia and temperatures and lower hematocrit values than did adults at the time of admission. No major side effects in the patients were observed.

Widespread in vitro resistance to chloroquine of Plasmodium falciparum in the Congo, 1987.

The drug sensitivity of 184 Plasmodium falciparum isolates was studied in vitro in three areas of the Congo in January 1987. Results show that parasites resistant to chloroquine but not to quinine or mefloquine were prevalent in the three investigated regions, but the drug response pattern varied widely. In Brazzaville, after the outburst of chloroquine resistance in 1985, prevalence of chloroquine resistant isolates seemed to have stabilized around 60%.

[Plasmodium falciparum drug resistance in the Congo. Evaluation of surveys carried out from 1985 to 1989].

Surveys on drug sensitivity of Plasmodium falciparum carried out between 1985 and 1989 included 7-day in vitro tests and in vivo tests. 485 in vivo tests were carried out in eight surveys conducted in Brazzaville and in several inland regions. The subjects were congolese children aged between 3 months and 15 years old.

Patterns of in vitro resistance to chloroquine, quinine, and mefloquine of Plasmodium falciparum in Cameroon, 1985-1986.

The drug sensitivity of 246 Plasmodium falciparum isolates was studied in vitro in five areas of Cameroon at the end of 1985. Results demonstrate that parasites resistant either to chloroquine, quinine, or mefloquine, or to two of these drugs, were prevalent in four of the areas investigated, but the drug response pattern varies widely from one area to another. The recent explosive emergence of chloroquine resistance in the south of the country, where both prevalences and levels are very high (up to 86%), contrasts with only moderate levels of resistance in the north.

Activity of a combination of three cinchona bark alkaloids against Plasmodium falciparum in vitro.

In vitro studies with quinine, quinidine, cinchonine, and cinchonidine showed that despite a similarity of chemical structure, the effectiveness of these cinchona bark alkaloids against several culture lines of Plasmodium falciparum varied widely. Depending on the strain tested, quinidine and cinchonine were 1 to 10 and 1 to 5 times, respectively, more active than quinine. A combination made of equal parts of quinine, quinidine, and cinchonine was found to have several interesting features; it had activity similar to that of quinine against quinine-susceptible strains but was found to be 2 to 10 times more effective against strains resistant to quinine and had a more consistent effect than any of the alkaloids used singly.