In vitro evaluation of quinidine sensitivity in brazilian Plasmodium falciparum isolates: comparative analysis to quinine and chloroquine Avaliação da sensibilidade in vitro à quinidina em isolados brasileiros de Plasmodium falciparum: análise comparativa à quinina e à cloroquina

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Carla M. S. MENEZES, Karin KIRCHGATTER, Sílvia Maria DI SANTI, Gilberto A. PAULA, Elizabeth I. FERREIRA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2001
• Subjects: Quinidine; Malaria; Quinine; Chloroquine; P. falciparum; Antimalarial resistance; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic
• Online Access: https://doi.org/10.1590/S0036-46652001000400009; https://doaj.org/article/2015198ea2314848a09a55237b682f9f

Falciparum malaria represents a serious and an increasing world public health problem due to the acquired parasite's resistance to the most available drugs. In some endemic areas, quinidine, a diastereoisomer of the antimalarial quinine, has been employed for replacing the latter. In order to evaluate the use of quinidine as an alternative to the increasing loss of quinine effectiveness in Brazilian P. falciparum strains, as has been observed in the Amazon area, we have assayed quinidine, quinine and chloroquine. The in vitro microtechnique was employed. All isolates showed to be highly resistant to chloroquine. Resistance to quinine was not noted although high MIC (minimal inhibitory concentration) values have been observed. These data corroborate the decreasing sensitivity to quinine in strains from Brazil. Quinidine showed IC50 from 0.053 to 4.577 mumol/L of blood while IC50 from 0.053 to 8.132 mumol/L of blood was estimated for quinine. Moreover, clearance of the parasitemia was observed in concentrations lower than that used for quinidine in antiarrhythmic therapy, confirming our previous data. The results were similar to African isolate. Malária falciparum representa grave e crescente problema de saúde pública mundial, dada a resistência do parasito à maioria dos fármacos disponíveis. Em algumas áreas endêmicas, a quinidina, diastereoisômero do antimalárico quinina, vem sendo empregada em substituição a este último. Com o objetivo de avaliar o emprego da quinidina como alternativa à perda crescente de sensibilidade de cepas brasileiras de P. falciparum à quinina, como o observado na região Amazônica, realizamos ensaio comparativo entre quinidina, quinina e cloroquina. A técnica in vitro do microteste de sensibilidade foi utilizada. Todos os isolados mostraram-se altamente resistentes à cloroquina. Resistência à quinina não foi observada, embora altos valores de CMI (concentração mínima inibitória) tenham sido encontrados. Estes resultados corroboram o decréscimo de suscetibilidade de cepas brasileiras à ...