In-vitro susceptibility of Plasmodium falciparum to monodesethylamodiaquine, dihydroartemisinin and quinine in an area of high chloroquine resistance in Rwanda.
Plasmodium falciparum in-vitro susceptibility to chloroquine (CQ), monodesethylamodiaquine, quinine and dihydroartemisinin was investigated in Rwandan patients with a parasitaemia of at least >or=4000/microl. The study was carried out in November-December 2003. Dihydroartemisinin was the most potent (GM IC(50)=2.6nmol/l, 95% CI 2.2-3.2) among the drugs tested. Resistance to chloroquine was 45% (33/74) and that to monodesethylamodiaquine 7% (5/74). All the tested isolates were susceptible to quinine. The mean IC(50) of monodesethylamodiaquine, quinine and dihydroartemisinin was significantly higher for chloroquine-resistant than for chloroquine-sensitive strains (P<0.05). The IC(50) of each drug was significantly and positively correlated to that of the other three drugs (P<0.005), and this correlation was higher between CQ and monodesethylamodiaquine (r=0.8). In-vitro CQ resistance is linked to that of the other drugs tested. Most worrying is the positive correlation between the IC(50) of dihydroartemisinin and the other drugs, more particularly with CQ, suggesting an increased tolerance of the parasites to all drugs.
Tinto
Halidou
H
Institut de Recherche en Sciences de la Santé/Centre Muraz, Bobo Dioulasso, Burkina Faso. tintohalidou@yahoo.fr
Rwagacondo
Claude
C
Karema
Corinne
C
Mupfasoni
Denise
D
Vandoren
Waltruda
W
Rusanganwa
Emmanuel
E
Erhart
Annette
A
Van Overmeir
Chantal
C
Van Marck
Eric
E
D'Alessandro
Umberto
U
D000293:Adolescent; D000328:Adult; D000655:Amodiaquine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology* / Q000627:therapeutic use; D037621:Artemisinins / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D005260:Female; D006801:Humans; D007223:Infant; D020128:Inhibitory Concentration 50; D016778:Malaria, Falciparum / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D010963:Plasmodium falciparum / Q000187:drug effects*; D011803:Quinine / Q000494:pharmacology; D012432:Rwanda; D012717:Sesquiterpenes / Q000494:pharmacology
D000962:Antimalarials; D037621:Artemisinins; D012717:Sesquiterpenes; D000655:Amodiaquine; C039060:artenimol; C047386:desethylamodiaquine; D002738:Chloroquine; D011803:Quinine