Benazepril side effects: what to expect

Benazepril is a drug commonly used to treat high blood pressure. It falls into a class of medications called ACE inhibitors, which relax blood vessels and keep blood pressure under control. 

These medications effectively treat high blood pressure and reduce the risk of heart attacks and stroke, but there are some side effects to watch out for. People with high blood pressure are often prescribed multiple medications, so it’s essential to check what drugs or supplements are safe to use with benazepril and which ones are not.

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Benazepril is generally safe for most patients, but there are some potential side effects to be aware of.

The most common side effects include dizziness, headache, fatigue, nausea, and coughing. A persistent, dry cough is often associated with ACE inhibitors and can be bothersome enough that people stop taking the medication altogether. If this is the case, there are types of other blood pressure medications that your healthcare provider can recommend. 

Severe or life-threatening side effects don’t happen often but do occur. Here are some of the more severe adverse reactions to watch out for if you’re taking benazepril (Dahal, 2020):

• Angioedema: Benazepril can cause angioedema, a life-threatening allergic reaction that causes rapid swelling in the face and neck. If you experience these symptoms, seek medical attention immediately. 

• Liver failure: While rare, ACE inhibitors can lead to liver failure. Signs of liver failure include jaundice (yellowing of the skin or whites of the eyes).

• Hyperkalemia: Benazepril may cause potassium levels to increase in the body, a condition called hyperkalemia. It’s easy to treat and symptoms are typically mild, however, left untreated hyperkalemia can lead to deadly heart problems. 

• Agranulocytosis: Agranulocytosis, which is a very low white blood cell count, is a serious side effect. This condition can be dangerous as people with not enough white blood cells are at a much higher risk of infection. Agranulocytosis may be seen in people who have kidney problems in addition to heart disease (Hashmi, 2016).

• Low blood pressure: Since benazepril is responsible for lowering blood pressure, it can sometimes go too far and result in a drop in blood pressure below the normal range. Symptoms include dizziness, nausea, and loss of consciousness. If you experience any of these symptoms, speak with a healthcare provider as a dosage change may be necessary. 

• Severe allergic reactions: If you have ever experienced an allergic reaction to benazepril or other ACE inhibitors, do not take this medication. Signs of an allergic reaction include itching, hives, and difficulty breathing. If you experience any of these symptoms, seek emergency medical attention. 

Benazepril, also found under the brand name Lotensin, is an effective drug for managing high blood pressure. 

Like other ACE inhibitors, benazepril works by blocking an enzyme that usually causes vessels to constrict. It’s kind of like converting a four-lane highway to a two-lane, which increases the amount of traffic. In our case, the same volume of blood is traveling through a much smaller space, causing blood pressure to rise. By blocking these enzymes, blood vessels stay relaxed and open, which helps lower blood pressure (Herman, 2020).  

Additionally, ACE inhibitors yield long-term benefits like a reduced risk for heart attacks, preventing migraines, and reducing the risk of kidney damage in people with diabetes. These are just a few reasons why benazepril—especially when combined with other appropriate blood pressure medications—is a good option for treating hypertension (Herman, 2020).

You may be prescribed benazepril on its own or with other medications. Research is also shifting towards combination drugs (like amlodipine/benazepril) to treat high blood pressure. Multiple medications are often more effective compared to just one drug alone.

While that’s good news, taking drugs simultaneously means there’s more of a chance for drug interactions to occur. Here are some medications and supplements benazepril may interact with (FDA, 2014):

• Diuretics: If you’re taking diuretics (also called water pills) at the same time as benazepril, it could cause an excessive drop in blood pressure.

• Medications that affect potassium levels: Mixing benazepril with any medications or supplements containing potassium could lead to hyperkalemia (high potassium levels in the blood).

• Diabetes medications: This medication may raise the risk for hypoglycemia (low blood sugar) if you’re taking diabetes medications like insulin, for example.

• Non-steroidal anti-inflammatory drugs (NSAIDs): NSAIDs can reduce the effectiveness of benazepril. Mixing the two may also compromise kidney function, especially for older adults or patients on diuretic therapy. 

• Drugs that block the renin-angiotensin-aldosterone system (RAAS): RAS inhibitors are another class of medications that treat high blood pressure. Use caution taking with benazepril as it increases the risk for hyperkalemia, low blood pressure, and impaired kidney function.

• mTOR inhibitors: Primarily used for treating cancer, mTOR inhibitors can trigger angioedema if combined with benazepril.

• Lithium: Lithium is commonly used to treat mood disorders, such as bipolar disorder. It’s important to monitor your lithium levels closely when taking benazepril as ACE inhibitors can cause a lithium overdose.

Benazepril carries a U.S. Food and Drug Administration (FDA) black box warning—the most severe type of warning the FDA issues.

Do not use this drug if you are pregnant or suspect you might be. ACE inhibitors like benazepril are toxic to a developing fetus, and exposure could lead to devastating health consequences for the fetus or even death. In the case of nursing mothers, low levels of benazepril have been found in breastmilk, but it’s not enough to cause any adverse reactions in infants who are nursing (FDA, 2014).  

Others who should use caution when taking benazepril or avoid taking altogether include:

• People with a history of angioedema 

• Those with heart disease or who’ve had a past heart attack

• Individuals with health conditions that affect the liver or kidneys 

Along with your prescribed medications, it’s important to follow a heart-healthy lifestyle, including exercising regularly, maintaining a healthy diet, and regulating stress (Tsai, 2020).  

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

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Current version

April 15, 2021

Written by

Anna Brooks

Fact checked by

Yael Cooperman, MD

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About the medical reviewer

Yael Cooperman, MD, Ro

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.