In vitro chloroquine resistance modulation study on fresh isolates of Brazilian Plasmodium falciparum: intrinsic antimalarial activity of phenothiazine drugs

• Autor(a) principal: Menezes,Carla MS
• Data de Publicação: 2002
• Outros Autores: Kirchgatter,Karin, Di Santi,Sílvia M, Savalli,Carine, Monteiro,Fabiola G, Paula,Gilberto A, Ferreira,Elizabeth I
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Memórias do Instituto Oswaldo Cruz
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762002000700018
• topic: antimalarial; chloroquine; multidrug resistance; phenothiazines; modulating agents; chemosensitizer agents

Phenothiazine drugs - fluphenazine, chlorpromazine, methotrimeprazine and trifluoperazine - were evaluated as modulating agents against Brazilian chloroquine-resistant fresh isolates of Plasmodium falciparum. Aiming to simulate therapeutic schedules, chloroquine was employed at the concentration used for sensitive falciparum malaria treatment and anti-psychotic therapeutic concentrations of the phenothiazine drugs were adopted in two-fold serial dilutions. The in vitro microtechnique for drug susceptibility was employed. Unlike earlier reported data, the phenothiazine modulating effect was not observed. However, all the drugs demonstrated intrinsic antiplasmodial activity in concentrations lower than those described in the literature. In addition, IC50 estimates have been shown to be inferior to the usual anti-psychotic therapeutic concentrations. Statistical analysis also suggested an increase in the parasitaemia rate or, even, a predominant antiparasitic effect of phenothiazine over chloroquine when used in combination.