Antimalarial drug therapy is a cornerstone of the WHO strategy for malaria eradication. Antimalarial drug resistance is a problem in many parts of the world necessitating multi drug therapy. However since the early 1990s concerns have surrounded the cardiac electrophysiological effects of these drugs resulting in black box warnings for cardiac side effects. These have prevented mass drug administration and mass multi drug therapy in areas of malarial endemicity. However the underlying electrophysiological effect of these drugs if any has been poorly researched especially in combination. Here we use a loose patch clamp technique and intact right ventricular murine preparations to assess the effect if single and multidrug therapy on sodium and potassium channel function in an intact right ventricular preparation. We find significant reductions in sodium current with medloquine and chloroquine as well as indicators of am effect on potassium channel function with artemether/amodiaquine combination. Further data will confirm these effects and the effect on calcium homeostasis in the cell.