Fig. (1) Summary of picture from previously published pharmacokinetic studies for piperaquine. A graphic which is located on top-left-corner of the picture indicate a multiple dose concentration with 3-days course. A picture which is situated on bottom-right-corner exhibit a multiple dose concentration with 1-day course of the drug. All the 3-days course of the drug are in agreement of above-5 ng/ml concentration of the drug (the lower quartile is still above 1 ng/ml). While 1-day course regimen, with regards to the varying dosage of the drug, is below 1 ng/ml. It is indicative of potential threshold of measurable adherence assessment.