When treating or managing a case of heart enlargement, ACE inhibitors and ARBs are commonly prescribed medications, these are the two powerful classes of medications that can significantly improve heart function and reduce symptoms. However, like any other medication, they can also come with potential side effects. Understanding these reactions helps us take control of treatment and address concerns early on. This article goes through the most common side effects of ACE inhibitors and ARBs.

Though these medications are effective, they have side effects which include a persistent dry cough (more common with ACE inhibitors), dizziness or low blood pressure, elevated potassium levels, and potential changes in kidney function. In rare cases, they may also cause angioedema, a serious swelling of the lips, face, or throat that requires prompt medical attention. Dizziness is the most frequent side effect of ARBs; cough and angioedema are less likely to occur since ARBs do not raise bradykinin levels, which are linked to these responses.^2,4,5

Cardiomegaly and its causes

Heart enlargement, also known as cardiomegaly is when the heart is bigger than its usual size and this could be due to a stretch or thickening. This is noted in various causes and is primarily due to increased effort from the heart. The most common cause of this is CAD or coronary artery disease.¹

Understanding ACE inhibitors and ARBs

ACE inhibitors

Angiotensin-converting enzyme (ACE) inhibitors are a class of medication that lower your blood pressure by interfering with the conversion of angiotensin that raises your blood pressure. High blood pressure is a significant risk factor for coronary disease, heart failure, stroke, and other cardiovascular conditions, which is why ACE inhibitors are medications used to treat these conditions.³

Mechanism

Angiotensin II is a key molecule in regulating blood pressure and heart function. It causes blood vessels to constrict, raises blood pressure, stimulates the release of aldosterone (which promotes sodium and water retention), and encourages the growth of vascular smooth muscle and cardiac cells. These effects can worsen conditions like heart enlargement.

ACE inhibitors help manage these effects by blocking the enzyme that converts angiotensin I into angiotensin II. With lower levels of angiotensin II, ACE inhibitors help relax blood vessels, reduce blood pressure, and prevent the remodelling of heart and blood vessel tissue. They also promote the excretion of sodium, reducing fluid buildup and easing the heart's workload.

Additionally, ACE inhibitors increase levels of bradykinin, a peptide that promotes vasodilation (blood vessel relaxation), further lowering blood pressure. However, this can also contribute to side effects like a dry cough.³

Adverse effects 

• ACE inhibitors can cause a few common side effects. One of the most frequent issues is a dry, persistent cough, which occurs in 1 to 10% of patients. This cough is often bothersome enough to require stopping the medication. Women are more likely to experience this side effect than men.
• Renal function can be affected, and some patients may experience a temporary decline in kidney function. This is especially true for those with pre-existing heart or kidney issues. Low blood pressure is also a concern, particularly for people already suffering from heart failure or dehydration.
• Hyperkalemia, or high potassium levels, is another potential risk, particularly for those with kidney problems or diabetes. Although rare, ACE inhibitors can also lead to liver issues like hepatitis, requiring the medication to be stopped.
• Dizziness: like many blood pressure medications, ACE inhibitors can cause dizziness, especially when standing up too quickly. It’s important to rise slowly from sitting or lying down to avoid lightheadedness or fainting.
• Headaches: mild headaches are also a common side effect of ACE inhibitors.⁴

Severe side effects  

Though rare, more serious side effects can occur with ACE inhibitors. These include:

• Angioedema (Swelling): this is swelling in the face, mouth, lips, tongue, or throat, and it can be life-threatening if it affects the airway. Immediate medical attention is necessary if swelling occurs in these areas.  
• Jaundice: yellowing of the skin or eyes, which indicates potential liver damage. This requires urgent medical evaluation.
• Allergic reactions: rashes or more severe reactions may occur, requiring immediate attention.⁴

Toxicity

In the case of an overdose, ACE inhibitors can lead to dangerously low blood pressure, kidney dysfunction, and electrolyte imbalance like high potassium or low sodium levels. If someone has overdosed, activated charcoal may be used if it is within an hour of ingestion. Fluids are the first step to treat low blood pressure, and sometimes vasopressors are needed. While there’s no specific antidote for ACE inhibitor toxicity, supportive treatment and monitoring can help manage these effects.³

ARBs

Mechanism

When there’s too much angiotensin in the body, fluid retention increases, leading to higher blood pressure. This elevated blood pressure causes blood vessels to narrow, which can further exacerbate the issue. To constrict blood vessels, angiotensin II requires binding to specific proteins known as receptors. Angiotensin receptor blockers (ARBs) prevent this binding, allowing the blood vessels to stay open and relaxed. As a result, blood flows more freely and with less pressure.²

Side effects 

The main side effect of ARBs is dizziness, which is common with most blood pressure medications. In rare cases, ARBs can affect kidney function, particularly in individuals with existing renal artery disease, which may impact blood flow to the kidneys.⁵

Comparing ACE inhibitors and ARBs in terms of side effects

ACE inhibitors and ARBs both target the renin-angiotensin system to lower blood pressure, but they do so in different ways, leading to distinct side effect profiles. ACE inhibitors reduces angiotensin production, which is effective in controlling blood pressure but can lead to side effects like a persistent dry cough, loss of taste, skin rashes, and, in rare cases, kidney damage. On the other hand, ARBs work by blocking angiotensin receptors, which typically results in fewer side effects. The most common side effect of ARBs is dizziness, and because they do not raise bradykinin levels, ARBs are less likely to cause a cough or angioedema, which are more commonly associated with ACE inhibitors.^2,3

Summary 

ACE inhibitors and ARBs are commonly used medications for treating heart enlargement, offering significant benefits by improving heart function and reducing symptoms. However, they can also cause side effects. ACE inhibitors often lead to side effects such as a persistent dry cough, dizziness, elevated potassium levels, and potential kidney issues. Rarely, they can cause angioedema, which is swelling of the lips, face, or throat. ARBs, which block angiotensin receptors rather than decreasing angiotensin production, typically have fewer side effects. Dizziness is the most common side effect of ARBs, and they are less likely to cause a cough or angioedema since they do not raise bradykinin levels. Despite their benefits, both medications require careful monitoring to manage potential adverse effects.

FAQs

What is heart enlargement?

Heart enlargement, also known as cardiomegaly is when the heart is bigger than its usual size and this could be due to a stretch or thickening. 

What are the common side effects seen with ACE inhibitors?

Common side effects of ACE inhibitors include dry cough, dizziness, headaches, fatigue, and elevated potassium levels. They may also cause low blood pressure, particularly when starting the medication.

When should you see a doctor?

In case of serious side effects like angioedema, which is swelling in areas like the tongue, throat, or face, visit your doctor immediately.

What are the side effects of ARBS?

The drugs in this class have similar but lower rates of side effects. The prominent side effect of ARBs is dizziness.

What are ACE inhibitors used for? 

ACE inhibitors are primarily used to treat high blood pressure, heart failure, chronic kidney disease, and to prevent strokes.

How do ARBs work differently from ACE inhibitors?

ARBs block angiotensin receptors to prevent blood vessel constriction, while ACE inhibitors reduce angiotensin production. ARBs generally cause fewer side effects, particularly related to dry cough.

Can I take ACE inhibitors or ARBs if I have kidney problems?

ACE inhibitors and ARBs can affect kidney function, so they should be used cautiously in patients with existing kidney issues. Regular monitoring of kidney function is recommended.