Ranolazine is a metabolic modulator developed by Syntex (Roche) and sold under the trade name Ranexa by Gilead Sciences. Ranexa has antianginal and anti-ischemic effects that do not depend upon reductions in heart rate or blood pressure. The mechanism of action of ranolazine is unknown. It does not increase the rate-pressure product, a measure of myocardial work, at maximal exercise. In vitro studies suggest that ranolazine is a P-gp inhibitor. Ranolazine is believed to have its effects via altering the trans-cellular late sodium current. It is by altering the intracellular sodium level that ranolazine affects the sodium-dependent calcium channels during myocardial ischemia. Thus, ranolazine indirectly prevents the calcium overload that causes cardiac ischemia. Because Ranexa prolongs the QT interval, it should be reserved for patients who have not achieved an adequate response with other antianginal drugs. Ranexa should be used in combination with amlodipine, beta-blockers or nitrates. The effect on angina rate or exercise tolerance appeared to be smaller in women than men.