Ranolazine dihydrochloride is primarily used in the treatment of chronic angina, a condition characterized by chest pain due to reduced blood flow to the heart. It works by improving the efficiency of the heart's use of oxygen, allowing patients to engage in physical activities with less discomfort. Unlike traditional angina medications, it does not significantly affect heart rate or blood pressure, making it a suitable option for patients who cannot tolerate other treatments. It is often prescribed when other anti-anginal therapies are not effective or appropriate. Additionally, it may be used in combination with other medications to manage symptoms and improve the quality of life for individuals with chronic angina.