Beta-blockers help to reduce the speed and force of your heartbeat while also lowering your blood pressure. They work by preventing the hormone adrenaline (epinephrine) from binding to beta receptors.

Like most drugs, beta-blockers can trigger side effects. Usually, doctors prescribe these medications because the risks associated with a particular condition outweigh the side effects beta-blockers can cause.

Keep reading to find out more about the potential side effects and drug interactions of beta-blockers, as well as precautions to take.

Beta-blockers are often prescribed for heart-related conditions, including:

There are beta-receptors all over your body, not just in your heart. As a result, beta-blockers are sometimes prescribed for other conditions, such as migraine, anxiety, and glaucoma.

Not all beta-blockers are created equal. There are many different beta-blockers, and each one works in a slightly different way.

Doctors consider many factors when deciding which beta-blocker to prescribe. These include:

  • the condition being treated
  • the risk of side effects
  • other conditions you have
  • other medications you’re taking

There are three main types of beta-blockers, each of which is described in more detail below. They are:

  • nonselective
  • cardioselective
  • third-generation

Nonselective beta-blockers

Approved in the 1960s, the first beta-blockers were nonselective. In other words, they acted on all the beta receptors in your body, including:

  • beta-1 receptors (heart and kidney cells)
  • beta-2 receptors (lung, blood vessel, stomach, uterus, muscle, and liver cells)
  • beta-3 receptors (fat cells)

Since these beta-blockers don’t differentiate between the various types of beta receptors, they pose a slightly higher risk of side effects.

This is especially true for people who smoke or have lung conditions such as asthma or chronic obstructive pulmonary disease (COPD).

Some common nonselective beta-blockers include:

Cardioselective beta-blockers

More recent beta-blockers were designed to target only beta-1 receptors in the heart cells. They don’t affect other beta-2 receptors and are therefore safer for people with lung conditions.

Some common cardioselective beta-blockers include:

Third-generation beta-blockers

Third-generation beta-blockers have additional effects that help to further relax blood vessels and ease high blood pressure.

Some common third-generation beta-blockers include:

Research into the use of third-generation beta-blockers is ongoing. Some studies suggest that these drugs may be a safe option for people with metabolic syndrome.

For example, according to a 2017 review of studies, nebivolol might be a suitable treatment option for people who have high blood pressure along with impaired sugar (glucose) and fat metabolism.

A 2019 study on mice concluded that carvedilol boosted glucose tolerance and sensitivity to insulin. These are both key factors in diabetes. Additional research is needed to understand if carvedilol has the same effects in humans.

Beta-blockers are relatively effective, safe, and affordable. As a result, they’re often the first line of treatment in heart conditions.

The most common side effects of beta-blockers are:

  • Fatigue and dizziness. Beta-blockers slow down your heart rate. This can trigger symptoms associated with low blood pressure (hypotension).
  • Poor circulation. Your heart beats more slowly when you take beta-blockers. This makes it more difficult for blood to reach your extremities. You might experience coldness or tingling in your hands and feet.
  • Gastrointestinal symptoms. These include upset stomach, nausea, and diarrhea or constipation. Taking beta-blockers with food may help relieve stomach symptoms.
  • Sexual dysfunction. Some people report erectile dysfunction when taking beta-blockers. This is a common side effect with medications that lower blood pressure.
  • Weight gain. This is a side effect of some older, nonselective beta-blockers. Doctors aren’t sure why it happens, but it may be related to how beta-blockers affect your metabolism.

Other less common side effects include:

  • Difficulty breathing. Beta-blockers can cause lung muscle spasms that make it difficult to breathe. This is more common in people who have lung conditions.
  • High blood sugar (hyperglycemia). Beta-blockers can trigger high blood sugar in people with diabetes.
  • Depression, insomnia, and nightmares. These side effects are more common with older, nonselective beta-blockers.

Seek medical attention right away if you experience any of the following side effects while taking beta-blockers:

Yes, beta-blockers can interact with other medications. Some of these include:

You should tell your doctor about all the medications and supplements you take.

It’s best to avoid drinking alcohol if you take beta-blockers.

Both beta-blockers and alcohol can lower your blood pressure. Combining the two could cause your blood pressure to drop too quickly. This could leave you feeling weak, dizzy, or lightheaded. You might even faint if you stand up too fast.

Of course, these side effects depend on both your prescribed dose of beta-blockers and how much you drink. While there’s no completely safe combination, having an occasional alcoholic drink may be less risky. But it’s best to check with your doctor first.

You should also talk with your doctor if avoiding alcohol is difficult for you. Other medications may be available.

Beta-blockers aren’t for everyone. They may pose a greater risk to people with the following conditions:

If you have one of the medical conditions listed above, your doctor will probably consider other options before prescribing a beta-blocker.

Talking to your doctor about your health and any medical conditions may help you avoid negative side effects.

  • Let your doctor know if you’re pregnant, trying to get pregnant, or breastfeeding.
  • To prevent drug interactions, provide your doctor with a list of all the medications and supplements you take.
  • Be honest about your alcohol, tobacco, and drug use. These substances can interact with beta-blockers.

It’s dangerous to stop taking beta-blockers suddenly, even if you’re experiencing side effects.

When you take beta-blockers, your body gets used to your heart’s slower speed. If you stop taking them suddenly, you could increase your risk of a serious heart problem, such as a heart attack.

Contact your doctor if you experience unpleasant side effects with beta-blockers that last for more than a day or two. Your doctor might suggest another type of medication, but you’ll still need to slowly taper your beta-blocker dose.

Beta-blockers are used to treat heart conditions. Like all medications, they carry a risk of side effects and interactions.

Before taking beta-blockers, it’s important to talk to your doctor about any health conditions you have, any medications and supplements you take, as well as your use of alcohol, tobacco, and any recreational drugs.

If you experience any troubling side effects, be sure to follow up with your doctor as soon as possible. Your doctor can help you safely taper off the beta-blockers and suggest a different medication.