Lercanidipine hydrochloride hemihydrate is an active pharmaceutical ingredient (API) used as a calcium channel blocker in medications for the treatment of hypertension. It works by relaxing the blood vessels, which helps to lower blood pressure and improve blood flow. This makes it effective in managing high blood pressure, reducing the risk of heart attacks, strokes, and kidney problems. It is often prescribed for patients who require long-term blood pressure control. Medications containing this API are typically taken orally, often in slow-release formulations to ensure a prolonged effect and minimize side effects like rapid heart rate or flushing. It is used as part of a comprehensive treatment plan that includes lifestyle changes such as diet and exercise.