Is Lisinopril a Diuretic? Uses and Side Effects

Lisinopril is a medication that is frequently prescribed to treat high blood pressure.

It is also approved by the U.S. Food and Drug Administration (FDA) as an adjunctive treatment for heart failure and a certain type of heart attack known as ST-segment elevation myocardial infarction (STEMI). In the U.S., around 116 million adults have hypertension.

This condition means systolic blood pressure (the top number) is higher than 130 mm Hg or diastolic blood pressure (the bottom number) is over 80 mm Hg. Of those who have high blood pressure, only 25% have it well-controlled. Medications like lisinopril can be effective for treating hypertension.

In this article, we’ll explore how lisinopril works, how it compares to other types of drugs, and alternatives. We’ll also discuss common risks and precautions, as well as how you should know when it’s time to see a medical provider.

Is Lisinopril a Diuretic?

On its own, lisinopril is not a diuretic. It is an angiotensin-converting enzyme inhibitor, also known as an ACE inhibitor.

ACE inhibitors help to relax the blood vessels to lower blood pressure, while diuretics help the body to get rid of water and sodium. Sometimes lisinopril is paired with the diuretic hydrochlorothiazide. This is known as combination therapy and is highly effective for treating high blood pressure.

In some cases, the drugs work better together than on their own. Lisinopril-hydrochlorothiazide is a single prescription that combines these two medications.

Lisinopril on its own is available as a generic or found under the brand names Prinivil and Zestril. Lisinopril paired with hydrochlorothiazide is available as a generic or found under the brand names Zestoretic and Prinzide.

What are Diuretics?

Diuretics are drugs that increase the amount of urine that the kidneys make to get rid of excess fluid. They are sometimes called water pills because they help remove excess water and salt from cells and flush it from the body.

They work for treating high blood pressure because they lower the amount of blood volume that the heart must work to pump.

Diuretics are mainly used for treating hypertensive disorders but may also be prescribed for:

• Heart failure
• Edema (tissue swelling)
• Kidney problems like kidney stones
• Liver failure

There are three types of diuretics that all work to reduce excess fluid in the body but have slightly different effects. 

• Thiazide diuretics widen blood vessels and block the sodium and water from being reabsorbed. This is the most common type of diuretic used for treating high blood pressure.

• Potassium-sparing diuretics block sodium and water from being reabsorbed.

• Loop diuretics reduce how much salt and water is reabsorbed.

What are ACE Inhibitors?

ACE inhibitors are a type of drug that stops the production of a hormone that makes blood vessels contract. When the hormone is blocked, the blood vessels are more relaxed, leading to lower blood pressure.

ACE inhibitors are prescribed to manage blood pressure problems, but may also be used as an adjunct therapy for:

• Heart failure
• Chronic kidney disease
• Coronary artery disease
• STEMI

How Does Lisinopril Work?

Lisinopril is an ACE inhibitor. It blocks a specific enzyme and prevents the hormone angiotensin I from being converted to angiotensin II. By blocking increased levels of angiotensin II, lisinopril decreases how the blood vessels constrict.

Just like a blood pressure cuff when it relaxes on the arm, ACE inhibitors decrease the pressure inside blood vessels, making blood flow easier. This lowers blood pressure and helps the heart pump with less effort. However, even though it reduces blood pressure, it does not reduce heart rate.

Lisinopril also has an effect on kidney function, preventing them from holding onto too much salt and water. When the body’s fluids are off balance, it can lead to elevated blood pressure.

Lisinopril takes effect quickly. It can impact blood pressure levels within 1 hour of taking, although the maximum effect of the drug may take up to 6 hours.

Lisinopril with Hydrochlorothiazide

When lisinopril is paired with hydrochlorothiazide, a diuretic, the two medications work together to reduce blood pressure through two important modes of action:

• Blocking the conversion of angiotensin I to angiotensin II, which keeps vessels dilated.
• Reducing the amount of salt and water in the body, therefore reducing the volume of blood the heart has to pump.

Together, these can help to effectively lower blood pressure.

Because this is a combination of 2 medications, there might be a chance of more side effects. Common side effects are:

• Headache
• Fatigue
• Heartburn
• Decreased libido

If a doctor has prescribed this medication for you, they feel that the benefits outweigh the risks. But it’s still important to communicate with your doctor about side effects or symptoms.

Lisinopril Alternatives

Sometimes lisinopril is not the best option to treat a patient. In such a case, medical providers may prescribe other drugs in the same class as lisinopril which are called ACE inhibitors.

These include:

• Benazepril (Lotensin)
• Captopril (Capoten)
• Fosinopril (Monopril)
• Perindopril (Aceon)
• Enalapril (Epaned, Vasotec)
• Moexipril (Univasc)
• Quinapril (Accupril)
• Ramipril (Altace)
• Trandolapril (Mavik)

Healthcare providers may also prescribe drugs that treat high blood pressure, like lisinopril but are a different drug type.

These include:

• Diuretics
• Vasodilators
• Calcium channel blockers
• Beta-blockers
• Combined alpha and beta-blockers
• Angiotensin II receptor blockers
• Alpha-blockers
• Alpha-2 receptor agonists
• Central agonists
• Peripheral adrenergic inhibitors

Precautions and Risks

Lisinopril comes with serious warnings for pregnant people. If you become pregnant while taking this medicine, inform your doctor immediately. Lisinopril can cause serious harm to the fetus.

Lisinopril may not be safe for the following health conditions or medical treatments:

• Kidney disorders or disease
• People who are being treated with dialysis
• People who are breastfeeding

Lisinopril may not be safe for people who are taking the following medications:

• Other angiotensin-converting enzyme inhibitors (ACEs)
• Diabetes medications
• Steroids
• Other medications for high blood pressure
• Potassium supplements

Make sure you tell your medical provider or pharmacist if you take any of the following, since they can cause interactions:

• Nonsteroidal anti-inflammatory medications (NSAIDs) like aspirin, ibuprofen, or naproxen
• Any vitamins or nutritional supplements
• Any herbal supplements

These are not complete lists of precautions. Be sure to follow your medical provider’s instructions. Ask your pharmacist if you have questions.

When to See a Medical Provider

If you are taking lisinopril and have questions, see your medical provider.

If you experience any serious side effects, speak to a healthcare provider right away. Signs of concern include:

• Upset stomach, nausea, or vomiting
• Light-headedness or feeling faint 
• Severe fatigue
• Chest pain
• Changes to your heart rate
• Yellow-tinged skin or eyes (jaundice)
• Decreased urine output
• Muscle cramps
• Fever, chills, or infection

If you experience swelling, breathing problems, or other signs of anaphylaxis, get emergency medical care right away.

How K Health Can Help

K Health offers affordable and convenient access to highly qualified doctors to treat and manage high blood pressure, as long as you are not having a hypertensive crisis.

You can meet with your K Health doctor from the comfort of your own home via the K Health app, all while knowing that you’re getting individualized and expert care.