Resistance of Plamodium falciparum to Antimalarial Drugs in Zaragoza (Antioquia, Colombia), 1998

Abstract

Plasmodium falciparum sensitivity to chloroquine (CHL), amodiaquine (AMO)

Sentinel network for monitoring in vitro susceptibility of Plasmodium falciparum to antimalarial drugs in Colombia: a proof of concept

“…A high prevalence (96.3%) of parasites with in vitro LS to CQ (IC 50 > 100 nM) was found at all sentinel sites. These results concur with the low efficacy of CQ against P. falciparum throughout Colombia that has been previously reported in therapeutic efficacy studies (Osorio et al 1999, blair et al 2001, blair-Trujillo et al 2002. Despite the fact that CQ was withdrawn for P. falciparum treatment in Colombia as early as 2000, it is still in use for P. vivax infections and remains available in the market, possibly enabling it to exert drug selection pressure on P. falciparum strains.…”

“…Clinical efficacy studies of antimalarial drugs in Colombia have shown therapeutic failures of up to 90% in patients with uncomplicated P. falciparum malaria treated with CQ. This evidence was the basis for changing the national antimalarial drug policy in 1999, when CQ was replaced by amodiaquine (AQ) combined with sulfadoxine/pyrimethamine (SP) as the treatment of choice (MS 1999, Osorio et al 1999, blair et al 2001, blair-Trujillo et al 2002. Similarly, therapeutic failures to AQ have reached up to 50% in the Pacific coast region and therapeutic failures to SP have reached up to 87% in the Amazon Region (Osorio et al 2007).…”

Effectiveness of Antimalarial Drugs

“…[74][75][76][77][78][79] Good efficacy (80 percent) persisted elsewhere -in southwestern Asia and on the Horn of Africa, where no parasitologic failures were reported among 362 evaluations 80,81 ; in southern Asia, where the failure rate was 18 percent (of 339 evaluations) by day 28 [55][56][57] ; and in South America, where the failure rate was 9 percent (of 50 evaluations) by day 7, 14 percent (of 42 evaluations) by day 14, and 6 percent (of 119 evaluations) by day 28. [82][83][84] The risk of resistance to sulfadoxine-pyrimethamine is relatively high in Southeast Asia and eastern Africa.…”

Eficacia de amodiaquina y sulfadoxina/pirimetamina en el tratamiento de malaria no complicada por Plasmodium falciparum en Nariño, Colombia, 1999-2002.

“…Un estudio realizado en 1985, en el cual se evaluó la sensibilidad in vitro de aislamientos de campo de P. falciparum a AQ, demostró que 1/30 (3,3%) aislamientos fue resistente al medicamento (11). Por otro lado, dos estudios realizados en Antioquia en 1998, en los cuales se evaluó la eficacia de AQ en el tratamiento de malaria demostraron que sólo el 3% (en Zaragoza) y el 7% (en Turbo) de los pacientes tratados presentaron falla terapéutica al medicamento (6,8). A pesar de la eficacia demostrada de AQ, su analogía con CQ y la posibilidad de resistencia cruzada con este medicamento permiten especular que el tiempo de vida útil de AQ en el tratamiento de malaria en áreas con alta resistencia a CQ es corto (12,13).…”