Inderal XL (Inderal XL Propranolol Hydrochloride Capsules) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Propranolol is a beta-blocker used to treat high blood pressure, irregular heartbeats, shaking (tremors), and other conditions. It is used after a heart attack to improve the chance of survival. It is also used to prevent migraine headaches and chest pain (angina). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Preventing chest pain can help improve your ability to exercise. Inderal LA (Propranolol) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. IndERAL 40 Tablet contains propranolol, a beta blocker. It works by affecting the body’s response to nerve impulses, especially in the heart. It slows down your heart rate and makes it easier for the heart to pump blood around the body. This prevents arrhythmias.