background: the capacity of human hbaa erythrocytes of non-malarious blood to withstand osmotic stress in the presence of five antimalarial drugs, chloroquine phosphate, quinine, fansidartm, coartemtm and halfantm was studied in vitro. materials and methods: aqueous solutions of four increasing concentrations of the drugs used in this investigation were in the order: 0.2%, 0.4%, 0.6% and 0.8% (...