Heart Health Heart Disease Treatment Ranexa for Treating Angina By Richard N. Fogoros, MD Richard N. Fogoros, MD Facebook LinkedIn Richard N. Fogoros, MD, is a retired professor of medicine and board-certified internal medicine physician and cardiologist. Learn about our editorial process Updated on February 09, 2022 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Yasmine S. Ali, MD, MSCI Medically reviewed by Yasmine S. Ali, MD, MSCI Facebook LinkedIn Twitter Yasmine S. Ali, MD, MSCI, is a board-certified preventive cardiologist and lipidologist. Dr. Ali is also an award-winning writer. Learn about our Medical Expert Board Print Pillbox/Ranexa Ranexa (ranolazine) is a relatively new drug with a unique mechanism of action that's used mainly for the treatment of chronic stable angina. It is sometimes used for other cardiovascular conditions that produce chest pain as well. Ranexa has been shown to significantly improve the amount of time patients with stable angina are able to exercise before developing symptoms. It was approved by the Food and Drug Administration (FDA) in 2008 as a first-line treatment for angina. What Is Angina? Angina is pain or discomfort in the chest that results from the heart muscle being deprived of oxygen-rich blood. Some describe the feeling as pressure or squeezing, and the discomfort can be felt in the shoulders, arms, neck, jaw, or back, in addition to the chest. Angina pain may even feel like indigestion. Angina is a symptom rather than a disease in and of itself. Usually, it signals that a person has atherosclerotic coronary artery disease (CAD), resulting in a narrowing of one or more of the coronary arteries. When people with CAD stress their hearts (for instance, when they exert themselves), the region of the heart muscle that is supplied by the narrowed artery can become ischemic, which means it is deprived of oxygen. When the heart muscle becomes ischemic, angina often occurs. How Does Ranexa Benefit Angina? Ranexa has a unique mechanism of action, and as a result it can be added to other medications to treat angina (such as beta-blockers and nitrates) to improve the control of this symptom. Originally it was believed that Ranexa caused the heart muscle to switch from using fatty acids to glucose for energy production. This process would reduce the amount of oxygen the heart muscle needed to function—and, thus, would diminish ischemia. More recently, however, researchers learned that the principal effect of Ranexa is actually to block what is called the "late inward sodium channel" in heart cells. This sodium channel increases the calcium concentration inside cardiac cells and increases the muscle contraction and energy usage of the heart muscle. By blocking this sodium channel (which it does only in ischemic cells, not healthy heart cells), Ranexa improves the metabolism in ischemic heart cells, reducing damage to the heart muscle and also reducing angina symptoms. When Is Ranexa Useful? The chief use of Ranexa is to treat people with chronic stable angina. Ranexa can significantly reduce the frequency of angina episodes and increase the amount of exercise that can be performed without experiencing angina. It is usually combined with standard drug therapy for angina. In addition to standard therapy, a few studies have suggested that Ranexa may also be useful in managing unstable angina, when the heart doesn't get enough blood flow or oxygen. Ranexa also has shown promise in the treatment of microvascular angina, chest pain that's due to abnormalities in the tiny arteries of the heart. How Is Ranexa Taken? Ranexa comes as 500 milligram and 1,000 milligram extended-release tablets, and generic forms of ranolazine are also available. The usual dose is 500 milligrams twice per day, but it may be increased to 1,000 milligrams twice per day. Ranexa is one of the drugs that should not be taken along with grapefruit or grapefruit juice, which can increase the blood levels of Ranexa and make side effects more likely. Side Effects with Ranexa The most common reported side effects of Ranexa are headache, constipation, and nausea. Other less serious side effects may include: Dizziness or a spinning sensationHeadacheDry mouthWeaknessRinging in the ears In addition, while taking Ranexa, it is important to pay attention to any of the following serious side effects and immediately call your physician if they occur: Feeling as though you might pass outSwelling in the hands, ankles, or feetSlow, fast, or pounding heartbeatsTremorsBlood in the urineUrinating less frequently or not at allShortness of breathRashes, bruising, tingling, numbness, pain, or muscle weakness Initially, a chief concern about Ranexa was that it can prolong the QT interval (a measurement of electrical activity within the heart) on an ECG (electrocardiogram). Some drugs with this effect can increase the risk of developing dangerous heart arrhythmias. However, careful studies have shown this risk to be minimal or nonexistent with Ranexa. In fact, Ranexa now has been shown to actually reduce the risk of developing ventricular arrhythmias and atrial fibrillation (conditions that cause abnormal heart rhythms) and is sometimes used off-label as an antiarrhythmic drug. In addition, people with cirrhosis (scarring) of the liver should not take Ranexa, and neither should people taking Saint-John’s wort and certain other medications for: Fungus infectionDepressionHIVTuberculosis (TB)Seizures Studies suggest that side effects are more common in people over 75 years of age, so this drug should be used with caution in older individuals. Pregnant women are advised not to take Ranexa. A Word From Verywell Ranexa is a unique drug that has proven to be useful in the treatment of chronic stable angina. It can be useful to patients with other chest pain syndromes as well. Was this page helpful? Thanks for your feedback! Did you know the most common forms of heart disease are largely preventable? Our guide will show you what puts you at risk, and how to take control of your heart health. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 4 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Kosiborod M, Arnold SV, Spertus JA, et al. Evaluation of ranolazine in patients with type 2 diabetes mellitus and chronic stable angina: results from the TERISA randomized clinical trial (Type 2 diabetes evaluation of ranolazine in subjects with chronic stable angina). J Am Coll Cardiol. 2013;61:2038. doi:10.1016/j.jacc.2013.02.011 Morrow DA, Scirica BM, Karwatowska-Prokopczuk E, et al. Effects of ranolazine on recurrent cardiovascular events in patients with non-ST-elevation acute coronary syndromes: the MERLIN-TIMI 36 randomized trial. JAMA. 2007;297:1775. doi:10.1001/jama.297.16.1775 Mehta PK, Goykhman P, Thomson LE, et al. Ranolazine improves angina in women with evidence of myocardial ischemia but no obstructive coronary artery disease. JACC Cardiovasc Imaging. 2011;4:514. doi:10.1016/j.jcmg.2011.03.007 Food and Drug Administration. Ranexa (ranolazine) extended-release tablets. Additional Reading Belardinelli L, Shryock JC, Fraser H. The mechanism of ranolazine action to reduce ischemia-induced diastolic dysfunction. Eur Heart J Suppl. 2006;8(suppl A): A10–A13. doi:10.1093/eurheartj/sui091 Chaitman BR. Ranolazine for the treatment of chronic angina and potential use in other cardiovascular conditions. Circulation. 2006;113:2462.doi:10.1161/CIRCULATIONAHA.105.597500