Benazepril

Primary Use

Benazepril is primarily prescribed to treat hypertension, commonly known as high blood pressure. It belongs to a class of medications called angiotensin-converting enzyme (ACE) inhibitors. By relaxing the blood vessels, it allows blood to flow more easily, which helps the heart pump more efficiently.

Treatment Goals

The main goal of using benazepril is to lower blood pressure to a healthy range. Maintaining controlled blood pressure levels is essential for preventing long-term health complications, including:

• Strokes
• Heart attacks
• Kidney problems

Combination Therapy

Benazepril may be used as a standalone treatment or in combination with other types of blood pressure medications, such as diuretics (water pills) or calcium channel blockers. Healthcare providers determine the best approach based on an individual's specific health needs and blood pressure goals.

Mechanism of Action

Benazepril belongs to a group of medicines known as angiotensin-converting enzyme (ACE) inhibitors. It works by blocking the action of a specific enzyme in the body that produces a substance called angiotensin II.

Relaxing Blood Vessels

Angiotensin II is a potent chemical that causes the muscles in the walls of blood vessels to contract and narrow. When benazepril prevents the production of this substance, the blood vessels remain relaxed and open wider. This process is called vasodilation.

Effects on the Heart and Blood Pressure

By widening the blood vessels, benazepril provides several benefits for cardiovascular health:

• Lower Blood Pressure: As blood vessels relax, the pressure within them decreases.
• Reduced Heart Strain: The heart does not have to pump as hard to move blood through wider vessels.
• Improved Blood Flow: Blood and oxygen can circulate more efficiently to the heart and other organs.

While benazepril helps control high blood pressure, it does not cure the condition. It must be taken regularly to maintain its effects on the vascular system.

Common Side Effects

The most frequently reported side effects of benazepril are generally mild and may include:

• Headache
• Dizziness
• Fatigue
• Nausea
• A dry, hacking cough that does not go away
• Drowsiness

Serious Side Effects

Seek medical attention immediately if you experience any of the following serious symptoms:

• Allergic reactions: Swelling of the face, throat, tongue, lips, eyes, hands, or lower legs; difficulty breathing or swallowing; or hoarseness.
• Liver problems: Yellowing of the skin or eyes (jaundice).
• Infection signs: Fever, sore throat, and chills.
• Low blood pressure: Feeling lightheaded or fainting, especially when standing up quickly.
• Kidney issues: Changes in how often you urinate or swelling in the feet and ankles.
• High potassium: Symptoms may include muscle weakness or a slow heart rate.
• Chest pain: Any new or worsening chest discomfort.

Your healthcare provider may perform regular blood tests to monitor your kidney function and potassium levels while you are taking this medication.

Fetal Toxicity

Benazepril can cause injury and even death to a developing fetus. When pregnancy is detected, this medication must be discontinued as soon as possible. Exposure to ACE inhibitors during the second and third trimesters has been linked to fetal and neonatal injuries, including low blood pressure, skull defects, kidney failure, and death.

Angioedema and Allergic Reactions

Serious and potentially life-threatening allergic reactions, known as angioedema, can occur at any time during treatment. This involves swelling of the face, extremities, lips, tongue, glottis, and larynx. If swelling affects the upper airway, it can cause obstruction. Research indicates that Black patients may have a higher risk of experiencing angioedema compared to non-Black patients.

Low Blood Pressure (Hypotension)

Excessive low blood pressure may occur, especially in patients who are salt- or volume-depleted. This risk is higher for individuals taking diuretics, those on a salt-restricted diet, or those experiencing vomiting or diarrhea. Hypotension is most likely to occur when first starting the medication or when the dosage is increased.

Kidney and Liver Function

Benazepril may affect kidney function, particularly in patients with pre-existing kidney disease or severe heart failure. In rare cases, ACE inhibitors have been associated with a syndrome that begins with yellowing of the skin or eyes (jaundice) and can progress to severe liver damage. Monitoring of kidney and liver function is often necessary during treatment.

High Potassium Levels (Hyperkalemia)

Elevated levels of potassium in the blood may occur. Risk factors for developing hyperkalemia include:

• Kidney impairment
• Diabetes mellitus
• Concurrent use of potassium-sparing diuretics
• Use of potassium supplements or salt substitutes containing potassium

Other Precautions

• Cough: A persistent, dry, nonproductive cough may develop. This typically resolves once the medication is stopped.
• Blood Cell Changes: Rarely, benazepril may cause a decrease in white blood cells (neutropenia or agranulocytosis), which can increase the risk of infection. This is more common in patients with kidney issues or certain autoimmune conditions.
• Surgery and Anesthesia: Patients undergoing major surgery or receiving anesthesia may experience a significant drop in blood pressure while taking this medication.

Pregnancy

Using benazepril during the second and third trimesters of pregnancy can cause severe harm to the developing fetus. Exposure to this medication during pregnancy is associated with several serious risks, including:

• Kidney failure in the newborn
• Low blood pressure (hypotension)
• Skull deformities
• Underdeveloped lungs
• Reduced amniotic fluid levels

If you become pregnant while taking benazepril, you should contact your healthcare provider immediately. In most cases, the medication must be stopped as soon as possible to protect the fetus. Your doctor can help you transition to a different blood pressure treatment that is safer for use during pregnancy.

Breastfeeding

Benazepril and its active components pass into breast milk in very small amounts. While the levels found in milk are generally considered low, the potential effects on a nursing infant are not fully understood. Healthcare providers typically advise weighing the benefits of breastfeeding against the potential risks to the infant. It is important to consult with a medical professional to determine the best course of action for your specific situation.

Available Forms

Benazepril is available as a tablet to be taken by mouth. It is used as a standalone treatment or in combination with other medications.

Common forms include:

• Oral Tablet: The standard form for benazepril when used alone.
• Combination Oral Tablet or Capsule: Benazepril may be combined with other blood pressure medications, such as amlodipine or hydrochlorothiazide, in a combined dosage form.

FDA Approval and Indications

Benazepril was first approved by the U.S. Food and Drug Administration (FDA) in 1991. It is indicated for the treatment of hypertension (high blood pressure) to lower blood pressure in adults and children aged 6 years and older. It may be used as a standalone treatment or in combination with other blood pressure medications, such as thiazide diuretics.

Boxed Warning: Fetal Toxicity

The FDA requires a boxed warning for benazepril because drugs that act directly on the renin-angiotensin system can cause injury and even death to a developing fetus. Patients should discontinue benazepril as soon as pregnancy is detected to avoid these risks.

Safety Communications and Contraindications

The FDA has issued specific safety communications and contraindications regarding the use of benazepril:

• Aliskiren: Benazepril is contraindicated for use with aliskiren in patients with diabetes. This combination should also be avoided in patients with moderate to severe renal impairment due to the increased risk of low blood pressure, high potassium levels, and changes in kidney function.
• Angioedema: There is a regulatory warning regarding the risk of angioedema (severe swelling of the face, lips, tongue, or throat). The risk is higher in patients with a history of angioedema and those taking certain other medications, such as neprilysin inhibitors.
• Dual Blockade: Using benazepril with other drugs that block the renin-angiotensin system is generally associated with an increased risk of hypotension, hyperkalemia, and changes in renal function.

Benazepril is available only by prescription and is not approved for over-the-counter use.

Stopping Treatment

Benazepril is used to manage chronic conditions like high blood pressure. It helps control these conditions but does not cure them. If you stop taking the medication, its protective effects will wear off and your blood pressure will likely rise again.

Important considerations for discontinuing benazepril include:

• Medical Supervision: Do not stop taking this medication without first consulting your doctor. High blood pressure often has no symptoms, so you may not feel a difference if you stop, but your risk of heart attack or stroke may increase.
• Consistency: To maintain stable blood pressure levels, the medication must be taken exactly as prescribed. Missing doses or stopping abruptly can lead to rebound hypertension.
• Consultation: If you are experiencing side effects that make you want to stop the medication, talk to your healthcare provider. They can determine if a dosage adjustment or a different medication is necessary.