title: In vitro susceptibility of Gabonese wild isolates of Plasmodium falciparum to artemether, and comparison with chloroquine, quinine, halofantrine and amodiaquine.
abstract: The in vitro activity of artemether against 63 African isolates of Plasmodium falciparum from Libreville, Gabon was evaluated using an isotopic drug susceptibility semi-microtest. The 50% inhibitory concentration (IC50) values for artemether were in a narrow range from 0.8 to 34.8 nM (mean IC50 5.0 nM) and the 95% confidence interval (CI95%) was 3.6-6.3 nM. In vitro decreased susceptibility or resistance were observed with artemether (14%), to chloroquine (90%), to quinine (32%). Isolate susceptibility to amodiaquine and halofantrine was high i.e. 100% and 98%, respectively. There was a significant positive correlation between responses to artemether and amodiaquine (r2 = 0.45, P < 0.001), artemether and chloroquine (r2 = 0.36, P < 0.001), artemether and quinine (r2 = 0.31, P < 0.001), and artemether and halofantrine (r2 = 0.19, P < 0.01). Positive correlation between these drugs suggests in vitro cross-resistance or at least common features in drug uptake and/or mode of action or resistance.
authors.affiliation: Unité de Parasitologie, Institut de Médecine Tropicale du Service de Santé des Armées, Marseille, France.
authors.forename: B
authors.initials: B
authors.lastname: Pradines
authors.forename: M
authors.initials: M
authors.lastname: Mabika Mamfoumbi
authors.forename: D
authors.initials: D
authors.lastname: Parzy
authors.forename: M
authors.initials: M
authors.lastname: Owono Medang
authors.forename: C
authors.initials: C
authors.lastname: Lebeau
authors.forename: J R
authors.initials: JR
authors.lastname: Mourou Mbina
authors.forename: J C
authors.initials: JC
authors.lastname: Doury
authors.forename: M
authors.initials: M
authors.lastname: Kombila
mesh_terms: D000293:Adolescent; D000655:Amodiaquine / Q000494:pharmacology; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D000077549:Artemether; D037621:Artemisinins; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000494:pharmacology; D004352:Drug Resistance, Microbial; D005681:Gabon; D006801:Humans; D007223:Infant; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000469:parasitology; D010616:Phenanthrenes / Q000494:pharmacology; D010963:Plasmodium falciparum / Q000187:drug effects*; D011803:Quinine / Q000494:pharmacology; D012717:Sesquiterpenes / Q000494:pharmacology*
chemical_list: D000962:Antimalarials; D037621:Artemisinins; D010616:Phenanthrenes; D012717:Sesquiterpenes; D000655:Amodiaquine; D002738:Chloroquine; D011803:Quinine; D000077549:Artemether; C023768:halofantrine