Interaction between lumefantrine and monodesbutyl-benflumetol in Plasmodium falciparum in vitro

The pharmacodynamic interaction between lumefantrine and its monodesbutyl analogue (DBB) has been investigated in 35 fresh isolates of Plasmodium falciparum. Both compounds showed highly significant activity correlation. The geometric mean values for complete inhibition of schizont maturation (GMCOC) were 536,8 nM for lumefantrine, 246.0 nM for DBB, 235,5 nM for LUM-DBB 999:1, and 155,2 nM for LUM-DBB 995:5, with significant activity differences between lumefantrine and DBB as well as the LUM-DBB combinations. For the combination of lumefantrine and DBB 995:5 the sums of the fractional inhibitory concentrations according to Berenbaum (SFIC) indicated marked synergism, the intensity of interaction rising with the effective inhibitory concentrations.