Figure 2.

Worsening resistance; the antimalarial concentration-effect relationship moves to the right. In this example the shift is parallel. IC50 is the concentration giving 50% of maximum effect, and Emax is the maximum effect possible. Usually in-vitro susceptibility is assessed by growth inhibition, inhibition of uptake of ³H Hypoxanthine, or inhibition of formation of pLDH or PfHRP2.