Ranolazine: An Antiarrhythmic and Cardioprotective Agent.

Ranolazine is a drug with a dual mode of action as a metabolic modulator and membrane stabilizer. It is better known for its anti-ischemic and antianginal properties rather than its antiarrhythmic effects. It also possesses favorable antioxidant capacity and effects on glycemic control. Ranolazine is listed in current guidelines as a second-line agent for chronic angina. As mentioned, myocardial cells have high inward late-phase sodium-channel activity under ischemic conditions, followed by an increase in intracellular sodium levels, thus enhancing active exchange with extracellular calcium. Ranolazine is the agent that disrupts this inward sodium-channel activity during ischemia and thus can effectively reduce myocardial demand. Ranolazine increases exercise duration on treadmill testing and time-to-ischemia in patients with stable angina. Most articles discussing the best medical treatment for stable ischemic heart disease include ranolazine as part of this optimal therapeutic scheme. As guidelines state, ranolazine is an appropriate alternative for symptom relief when beta-blockers are contraindicated or not tolerated, and it can also be employed in combination with beta-blockers if monotherapy fails to provide sufficient symptom relief. Also, when beta-blockers and/or calcium channel blockers fail to successfully control the symptoms, ranolazine pitches in as an important second-line agent. This is also true when these primary therapeutic agents produce hypotension or severe bradycardia, as ranolazine does not exert a vasoactive and hypotensive action, nor does it have a bradycardic effect, except for extremely rare instances.