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% (w/v). Spectrophotometric method was employed to ascertain the osmotic fragility index of the erythrocytes. The mean corpuscular fragility (MCF) index (X+S.D) of the control sample was 0.351+0.06 g/100ml. The MCF values of the control and test samples were statistically compared (p value = 0.05).

Results: At the drug concentration of 0.8g, MCF values (g) of 0.401±0.005, 0.391±0.003, 0.364±0.02, 0.344±0.02 and 0.338±0.04 were obtained for halfan, coartem, quinine, chloroquine phosphate and fansidar, respectively.

Conclusion: An overview of the results showed that in a concentration dependent manner, Choroquine phosphate and FansidarTM exhibited a diminishing capacity to stabilize red blood cell membrane while HalfanTM CoartemTM and Quinine elicited an increasing propensity to disrupt erythrocyte membrane integrity.