Without any effect on myocardial, smooth muscle, or endothelial cells, ivabradine reduces heart rate by blocking the inward cellular sodium and potassium flux in the pacemaker cells of the sino-atrial node.13 Ivabradine may be introduced either in combination with a BB or as monotherapy. The most common side-effects are usually transient visual disturbances due to inhibition of retinal electrolyte currents, symptomatic bradycardia, and conduction abnormalities. As the drug is metabolized by the hepatic CYP3-A4 enzyme system, changes in plasma levels may occur if there is concurrent enzyme competition from other medication.