An ACE inhibitor
Enalapril
An ACE inhibitor for high blood pressure and heart failure; can cause a dry cough and is avoided in pregnancy.
What is Enalapril?
Enalapril is an ACE inhibitor used to lower blood pressure and to treat heart failure with a weakened pumping action. It works by relaxing and widening blood vessels, which lowers blood pressure and eases the work of the heart.
Education and reference only. This is a plain-language guide to Enalapril — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Enalapril is an ACE inhibitor. It lowers blood pressure and is a long-established treatment for heart failure with a reduced pumping function, where it helps the heart and improves outcomes. ACE inhibitors are usually among the first choices for these conditions. Enalapril is a long-term tablet, often started low and built up gradually. In the UK it is sold generically and under the brand Innovace; in the US it is known as Vasotec.
How it works
Enalapril blocks the angiotensin-converting enzyme (ACE), which the body uses to make angiotensin II — a hormone that tightens blood vessels and makes the body hold on to salt and water. With less angiotensin II, blood vessels relax and fluid load falls, so blood pressure drops and the heart has less to work against. In heart failure, easing this strain helps a struggling heart and is part of why ACE inhibitors improve survival.
Company & origin
Originated / developed by: Merck & Co..
Enalapril was developed by Merck & Co. in the early 1980s as a successor ACE inhibitor to captopril. It received US FDA approval in 1985 and was marketed as Vasotec (Innovace in the UK).
What it treats
Conditions Enalapril is used for
Practical use
How to take Enalapril
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it at the same time each day, with or without food.
- Take the first dose when you can rest, as it may cause dizziness, particularly if you also take a water tablet.
- Expect blood tests to check your kidney function and potassium levels around starting and after changes.
- Report a persistent dry, tickly cough, as this is a known effect of ACE inhibitors.
- Avoid anti-inflammatory painkillers and salt substitutes unless advised, and seek urgent help if your face, lips or tongue swell.
Weighing it up
Advantages & disadvantages of Enalapril
Advantages
- Lowers blood pressure and reduces the risk of stroke and heart problems.
- Improves symptoms and survival in heart failure.
- Can help protect the kidneys in some people.
- A long-established treatment with extensive evidence.
Disadvantages
- Commonly causes a persistent dry cough that some people cannot tolerate.
- Can raise potassium and affect kidney function, so blood tests are needed.
- May cause dizziness, especially with the first dose or alongside diuretics.
- Rarely causes serious swelling of the face, lips or throat (angioedema).
- Must not be used in pregnancy because of risk to the baby.
Practical use
Good to know
It is often started at a low level and built up, with blood-pressure and blood-test checks after starting and after increases. A dry, tickly cough is the most recognised nuisance effect and, if troublesome, is usually solved by switching to an ARB. The first dose can cause dizziness from a drop in blood pressure, so it is sometimes taken at bedtime to begin with. It can raise blood potassium and affect kidney function in some people, which is why blood tests are used. It must not be taken in pregnancy. Anti-inflammatory painkillers (NSAIDs), especially alongside a water tablet, can stress the kidneys.
Who should not take it / use with caution
- People who are pregnant or planning pregnancy — ACE inhibitors are contraindicated in pregnancy and switched beforehand.
- Anyone with a history of angioedema (sudden swelling of the lips, tongue or throat), including from a previous ACE inhibitor — a reason never to take it again.
- Used with caution in significant kidney artery narrowing, low blood pressure, or a high blood potassium level.
Monitoring
- Blood pressure
- Kidney function and blood potassium before and after starting/increasing
- For cough or any swelling
Side effects
- A persistent dry cough (common and harmless, but can be annoying).
- Dizziness or light-headedness, especially on standing or after the first dose.
- A rise in blood potassium or a change in kidney function (watched with blood tests); rarely, angioedema — sudden swelling of the face or throat needs emergency care.
Key interactions
- NSAID painkillers (e.g. ibuprofen) can reduce its effect and stress the kidneys, especially alongside a diuretic (the "triple whammy").
- Potassium supplements, potassium-based salt substitutes and certain diuretics can push potassium too high.
- Care with other blood-pressure-lowering medicines, with ARBs, and with lithium.
Available as: Tablets (several strengths). A liquid is available for those who cannot swallow tablets.
Answers
Enalapril: frequently asked questions
Why does enalapril make me cough?
ACE inhibitors can cause a persistent dry, tickly cough because of the way they affect natural body chemicals in the airways. It is harmless but can be annoying; if it bothers you, your prescriber can usually switch you to an ARB, which rarely causes a cough.
What is angioedema and why does it matter?
Angioedema is sudden swelling of the face, lips, tongue or throat. With an ACE inhibitor it is rare but a medical emergency, because throat swelling can affect breathing — call 999 if it happens. Anyone who has had it should never take an ACE inhibitor again.
Why must enalapril be stopped in pregnancy?
ACE inhibitors can harm a developing baby, so they are contraindicated in pregnancy. If you are pregnant, think you might be, or are planning pregnancy, tell your healthcare team promptly so they can switch you to a medicine that is safe to use.
Do I need blood tests on enalapril?
Yes. It can raise blood potassium and affect kidney function in some people, so your prescriber checks your kidney function and potassium before starting and after any increase, then periodically. These tests are routine and help keep treatment safe.
What is the difference between enalapril and Innovace or Vasotec?
They are the same medicine — enalapril is the generic (active-ingredient) name, Innovace is the UK brand name and Vasotec is the US brand name. The active ingredient is identical.
The wider class
About ACE inhibitors
Enalapril belongs to the ace inhibitors class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF: Enalapril maleate.
- NICE NG106: Chronic heart failure in adults.
- NICE CKS: Enalapril.
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