Antimalarial activity of azithromycin and erythromycin against Plasmodium berghei

Several antibiotics that inhibit protein synthesis on 70S ribosomes, including the macrolide erythromycin, and the azalides azithromycin (ZITHROMAX) and CP-63,956, demonstrated antimalarial activity against two strains of Plasmodium berghei. In a four-day in vivo test, the azalides were 25-fold more potent than erythromycin against the chloroquine-sensitive P. berghei N strain, and displayed additive effects with chloroquine. This effect was not observed with the erythromycin-chloroquine combination. Against the chloroquine-resistant P. berghei MSU/RC strain, the azalides were 60-fold more potent than erythromycin. Additive effects were observed with azalide-chloroquine combinations against this strain, but these results were not significantly different from the erythromycin-chloroquine combination.