Cetiedil is effective potassium channel blocker used as a peripheral vasodilator to treat patients with painful crises in sickle cell anemia and pain in the extremities caused by an arterial disease. Known pharmacological properties of the drug include vascular smooth muscle relaxation, inhibition of phosphodiesterase with the consequent increase in circulating cyclic AMP concentration, blockade of the effect of bradykinin and serotonin, analgesia, inhibition of platelet aggregation and the decrease of plasma and blood viscosity and plasma fibrinogen level. The antisickling effect of cetiedil is explained mainly in the light of the changes it induces in the activities of membrane-bound ATPases and the permeability properties of the erythrocyte membrane to cations and anions.