Propranolol

Key facts

• Propranolol is a non-selective beta-blocker (brand name Inderal) that slows the heart and lowers blood pressure by blocking adrenaline's effects on the heart and blood vessels.
• It treats high blood pressure, angina, certain irregular heart rhythms, essential tremor, migraine prevention, and the physical symptoms of situational anxiety.
• Never stop propranolol suddenly, especially if you have heart disease: abrupt withdrawal can cause a rebound surge in heart rate or blood pressure, chest pain, or a heart attack. Your doctor will taper the dose down gradually.
• Seek urgent care for a very slow heartbeat, fainting, severe breathlessness, or signs of a severe allergic reaction.

What propranolol treats

Propranolol treats high blood pressure, angina, and certain arrhythmias where a slower heart rate helps. It prevents migraine attacks and reduces essential tremor in the hands. It is also used for the physical symptoms of situational anxiety, such as a pounding heart before public speaking, and by specialists for portal hypertension and some symptoms of an overactive thyroid.

How propranolol works

Propranolol blocks beta-adrenergic receptors, stopping adrenaline and noradrenaline from speeding up the heart or acting on blood vessels. This slows the heart rate, reduces the force of each heartbeat, and lowers blood pressure, while also steadying tremor and blunting the adrenaline surge that drives migraine and anxiety symptoms.

Before you take it

• Avoid propranolol if you have asthma or severe COPD: blocking beta receptors in the airways can trigger a dangerous asthma attack, even at doses used for tremor or migraine.
• Avoid it if you have a very slow heart rate, certain heart block conditions, or uncontrolled heart failure.
• Tell your prescriber if you have diabetes, since propranolol can mask the warning signs of low blood sugar, such as a racing heart.
• Tell your prescriber about other heart or blood pressure medicines, since combining them can slow the heart too much.

Side effects

Common effects include fatigue, cold hands and feet, dizziness, sleep disturbance or vivid dreams, and nausea.

Stop and seek urgent medical care for any of these:

• Severe shortness of breath or wheeze.
• Chest pain or pressure.
• Fainting or a very slow heartbeat.
• Signs of a severe allergic reaction: rash, swelling, or difficulty breathing.

Safety essentials

• Never stop propranolol abruptly, particularly if you have angina or heart disease: your doctor must reduce the dose gradually to avoid rebound chest pain, high blood pressure, or an arrhythmia.
• Avoid propranolol if you have asthma or reactive airway disease, since even a low dose can trigger a serious attack.
• If you have diabetes, monitor your blood sugar closely, since propranolol can hide the usual warning signs of hypoglycemia.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.