Propranolol is a type of beta-blocker that helps the heart to beat slower and more steadily.

Researchers originally developed propranolol to treat angina pectoris but have since found uses for it in treating other conditions, such as migraine, anxiety, and hypertension.

However, not everyone will benefit from taking it due to some contraindications. For example, people living with diabetes should not take propranolol.

The following article reviews everything a person needs to know about the medication propranolol.

A British scientist named Sir James Black first developed propranolol over 50 years ago. As a type of beta-blocker, it works by changing how the heart reacts to certain nerve impulses. This change helps to slow the heart down and decrease blood pressure.

A person needs a prescription from their doctor for propranolol. Several companies manufacture it under the brand names Inderal, Inderal LA, InnoPran XL, and Hemangeol.

Propranolol comes in several forms, such as tablets, capsules, an oral solution (Hemangeol), and a solution used for injection.

The most common side effects of propranolol include:

  • nausea
  • drowsiness
  • diarrhea
  • wheezing or symptoms of bronchitis
  • fatigue (feeling weak)
  • coldness in extremities
  • slower heart rate (bradycardia)
  • abdominal pain
  • erectile dysfunction
  • gastrointestinal issues
  • dry eyes
  • insulin resistance

Some symptoms may be mild and go away within a few weeks as the body adjusts to the medication. A person should discuss any severe symptoms or symptoms that do not go away with their doctor.

Some less common but more severe symptoms can be associated with propranolol. A person who experiences any of the following symptoms should call their doctor right away:

  • breathing problems or bronchospasms
  • slow heart rate
  • allergic reactions, such as itching, rashes, and hives, or swelling in the face or tongue
  • sudden weight gain
  • swelling of legs, ankles, or feet
  • sudden changes in blood sugar
  • trouble sleeping or nightmares
  • hallucinations

People with breathing disorders such as asthma, bronchitis, or emphysema should not take propranolol. People with slow heartbeats or low blood pressure should avoid this medication as well.

Doctors will also need to know if the person is living with or has a history of:

  • liver or kidney disease
  • blood sugar problems or diabetes
  • circulation problems
  • thyroid disorders
  • congestive heart failure
  • allergies
  • muscular disorders
  • symptoms of depression

People who are pregnant or breastfeeding should also avoid taking propranolol.

Doctors typically prescribe propranolol alone or combined with other medications to treat high blood pressure.

High blood pressure makes the heart work too hard. If it is left unchecked, the heart and arteries may begin to wear down over time. The heart controls the blood supply and if it is not working properly it can cause damage to many areas of the body.

Typically, propranolol has a half-life of 3–6 hours, but long-acting propranolol can have a half-life of 8–11 hours due to slower absorption in the gut. This means it can take 4–5 half-lives for the medication to be fully effective, which is about 55 days in patients with normal renal function.

Doctors may also prescribe the medication to help prevent severe headaches and migraine, chronic chest pain, and to help treat or prevent heart attacks.

In addition, doctors may prescribe propranolol for:

  • portal hypertension
  • pheochromocytoma, a tumor of the adrenal gland
  • essential tremor
  • supraventricular arrhythmia, an abnormal rhythm in the top chambers of the heart
  • panic disorders
  • aggressive behaviors
  • restlessness caused by antipsychotics
  • infantile hemangioma

Can propranolol help with mental health conditions?

Negative emotions play a role in mental health conditions such as post-traumatic stress disorder (PTSD).

There are a number of ways healthcare professionals help people with negative emotions. According to a 2017 study, researchers found that propranolol can block the strengthening of emotional memories if taken before a person recalls the memory. This reduces the emotional memory in a way.

In other words, the person’s emotional attachment to the negative memory may not be as strong while taking propranolol. This could help people manage a negative emotional memory or traumatic event.

This research added to another study published in 2016, which found that people living with post-traumatic stress disorder (PTSD) have a better ability to think clearly while taking propranolol. These combined studies indicate that propranolol may play an effective role in helping people with PTSD.

Dosage for propranolol varies based on the condition a doctor prescribes it for, the form taken, and a person’s response to the medication.

For example, some common doses of a propranolol tablet include:

  • Hypertension: initial dose, twice daily 40 milligrams (mg); maintenance dose, 120 mg–240 mg per day
  • Atrial fibrillation: 10 mg–30 mg three to four times per day
  • Angina: 80 mg–320 mg daily
  • Migraine: initial dose, 80 mg per day; maintenance doses between 160 mg–240 mg per day
  • Essential tremor: initial dose, 40 mg twice per day; maintenance typically around 120 mg per day
  • Myocardial infarction (heart attack): initial dose, 40 mg three times per day; maintenance doses between 180 mg–240 mg per day, divided
  • Hypertrophic subaortic stenosis: 20 mg–40 mg three to four times per day

A person should ask their doctor about dosing for their condition and follow all directions they provide. They should also make sure they follow the directions written on the medication packaging and talk with their doctor or pharmacist if they have any questions.

A person should talk with their doctor if they notice any symptoms after a dose adjustment, particularly if the symptoms are severe or do not improve in a few days.

Taking other medications can interfere with how propranolol works in the body. Anyone taking a medication to treat heart rhythm problems should talk with their doctor before taking propranolol.

People switching from other blood pressure medications, such as clonidine, should do so slowly. Over the course of a few days, a person’s doctor may recommend slowly decreasing the dose of the other medication while increasing the dose of propranolol to avoid side effects.

A person should not take propranolol with other beta-blockers, ACE inhibitors, calcium channel blockers, and alpha-blockers, as the combined effect can lower the heart rate to an unsafe level and could trigger a heart attack.

People taking propranolol should also avoid nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. These drugs may reduce the effects of propranolol.

If a person needs to take NSAIDs, they should work directly with a doctor. The doctor can help to decide which drug is best and monitor the person’s heart rate in order to adjust the levels of each drug as needed.

Propranolol can also interact with other substances such as alcohol. Doctors typically recommend avoiding alcohol when taking propranolol since it can increase the levels of propranolol in the body, which can lead to side effects.

A person should discuss all medications, supplements, and other substances they take with their doctor. Their doctor can help determine if there are alternatives or can advise a person to stop taking other medications if needed.

Propranolol is a nonselective beta-adrenoceptor antagonist, otherwise known as a beta-blocker.

It works by preventing hormones, specifically beta-1 and beta-2, from interacting with the heart. By blocking these hormone receptors, beta-blockers, such as propranolol, help to slow down the heart.

In order to take propranolol and other beta-blockers, a doctor must prescribe them for a person.

Propranolol may present some risk to the developing fetus. Risks include:

  • small placentas
  • bradycardia
  • slower growth rate
  • hypoglycemia
  • congenital abnormalities
  • respiratory depression

As a result, a person who is pregnant or planning to become pregnant should talk with their doctor before taking propranolol. A doctor may prescribe the medication if they feel the benefit outweighs the risk to the developing fetus.

People concerned about or experiencing side effects and interactions from propranolol should talk with their doctor about alternative medications. Whether an alternative exists will depend on the condition a person is taking the medication to treat.

People experiencing side effects or at higher risk may find that a selective beta-blocker, such as metoprolol, may work better for them. Metoprolol is another type of beta-blocker, sometimes called a selective beta-blocker. It only blocks beta-1, not beta-2. This may help reduce the severity and risk of side effects.

Doctors may prescribe propranolol and metoprolol to treat similar conditions, such as angina, hypertension, and heart attacks. They are both forms of beta-blockers. They also share similar warnings, side effects, and interactions.

However, the two medications have some distinctions. Metoprolol is a selective beta-blocker. It only blocks beta-1, while propranolol blocks beta-1 and beta-2. This can make it less likely that a person will experience side effects from taking metoprolol, and many have reported that side effects tend to be mild.

A doctor may also prescribe propranolol for different medical conditions beyond high blood pressure and angina. By comparison, metoprolol’s usage is more specifically for heart attacks, high blood pressure, and angina.