Adverse Effects of Beta-Blockers

If you have been diagnosed with Heart Failure (HF), you may have been prescribed a beta-blocker. A beta-blocker is a class of medications commonly used to treat HF, high blood pressure, heart attacks, and arrhythmias. While these drugs are life-saving, they come equipped with adverse effects. Knowing and understanding how to manage these side effects will help you navigate your new treatment.

What are beta-blockers?

Beta-blockers are a large class of medications that block the effects of a hormone, adrenaline. Adrenaline is the hormone that triggers the fight-or-flight response. There are various different beta blockers within the class; an easy way to distinguish these drugs is by their name. All beta blockers end with “-lol”. Examples include the following:

• Propranolol
• Sotalol
• Metoprolol
• Labetalol
• Carvedilol
• Bisoprolol
• Atenolol

Common side effects

Before prescribing a beta-blocker, your doctor will ensure that the medication is safe and indicated. Some potential risks and unwanted side effects of beta-blockers are outlined below.

• Weight gain: Fat accumulation is more likely with the older agents, such as metoprolol and atenolol. Weight gain usually occurs in the first initial months of treatment, but stops and reaches a plateau thereafter. The average weight gain is 1.2 kg.¹
• Low blood sugars: This drugs class can worsen or extend a period of hypoglycaemia, or low blood sugar levels. This is especially concerning for people with diabetes. Beta-blockers can also mask the symptoms of low blood sugar, which may be problematic if people rely on symptoms alone to determine whether their sugars are low.²
• Worsening asthma and COPD: Some beta-blockers are not recommended for people with severe asthma or COPD, as they may cause narrowing of the respiratory tract and worsen respiratory symptoms. However, it was found that medications commonly used for asthma and COPD such as inhaled steroids are protective against this side effect³.

Minor risks with heart failure

Many people choose not to take beta-blockers due to concerns of depression and sexual dysfunction, which this class of medications has been linked to. However, studies have shown that the risk is very low. To summarize these trials:⁴

• Beta blockers do not increase the risk of depression.
• There is a small increase in the risk of sexual dysfunction. To put this risk into perspective, for every 200 people treated with a beta blocker, one person will experience sexual dysfunction.

If you are concerned about these side effects, it is a good idea to have a discussion with your doctor, as your underlying health factors can further predict these risks.

Withdrawal concerns

All of the side effects mentioned above are reversible when discontinuing the drug. However, it is very important that if a beta-blocker needs to be discontinued, that it be gradually tapered. Stopping beta-blockers abruptly can cause withdrawal syndrome, leading to high heart rate and high blood pressure.

There have also been reports of heart attacks with abrupt discontinuation. For this reason, it is very important that if you need to discontinue therapy that you speak to your doctor about a taper schedule.⁵

Do you take a beta-blocker? Have you experienced any of the side effects mentioned above? Share your experiences below!