Enalapril

What is Enalapril?

Enalapril is a type of medicine called an ACE inhibitor. It is used to treat high blood pressure (hypertension) and is often prescribed to patients who have experienced heart failure or a heart attack, or whose high blood pressure puts them at risk of a heart attack, heart failure or stroke in future. The generic drug Enalapril is also sold under the brand name Innovace.

How does Enalapril work?

Enalapril works by reducing the activity of a hormone in the body called angiotensin II. Angiotensin II helps to maintain the body’s blood pressure system and its function is to make the arteries narrow, which in turn raises the blood pressure. When angiotensin II is stopped from working so much (inhibited), the arteries are wider, which helps to reduce blood pressure. Enalapril is one of a number of drugs that work in this way, known as angiotensin-converting enzyme (ACE) inhibitors.

How long does Enalapril take to work?

Enalapril starts working to reduce your blood pressure within hours of taking your first dose. However, you may need to wait a few weeks before feeling better. It’s important to keep taking the medicine consistently, as prescribed, during this time.

Active ingredients

The active ingredient in Enalapril tablets is enalapril maleate.

Inactive ingredients

The inactive ingredients in Enalapril tablets are lactose, magnesium stearate, sodium bicarbonate, and starch. Note that Enalapril may not be suitable for you if you are allergic or intolerant to lactose.

How to start taking Enalapril

Patients are often advised to take their first dose of Enalapril before bed, because it can make you feel dizzy.   You may be prescribed a low dosage of Enalapril to start with, which might be increased over time. This gives your body a chance to get used to the medication, and reduces the chances of side effects like dizziness.

Enalapril is normally taken in tablet form, with a glass of water.

Enalapril Dosage

Enalapril is available in 2.5mg, 5mg, 10mg and 20mg tablets. The recommended dosage of Enalapril varies, depending on:  

• your kidney function
• the potassium levels in your blood
• whether you are just starting your first course of medication, and
• whether you are taking it for high blood pressure or heart failure.

The usual dosage for high blood pressure is one 20mg dose, once a day. The usual dosage for heart failure is one 10mg dose or one 20mg dose, once a day.   When you first start taking Enalapril, your dosage may be as low as 2.5mg once a day, which will be increased gradually if all goes well.  

Can Enalapril be crushed/split?

Enalapril is available in tablet or liquid form. If you wish to make the medicine more palatable by mixing it with food, it is better to use an accurately-measured liquid dose, rather than crushing a tablet. Always use the measuring spoon provided when measuring out a liquid dose of Enalapril.

Enalapril Side Effects

Most people will not experience any side effects when taking Enalapril. However, the following mild side effects are reported by some patients:

• Persistent, dry cough. If you experience this on an ongoing basis, an ARB drug may be a good alternative
• Dizziness. This is more likely to happen when you first start taking Enalapril, before your body gets used to the medication
• Headaches
• Diarrhoea
• Blurred vision
• Skin rash.

Serious side effects require immediate medical help. Contact a doctor if you experience any of the following:

• Yellowing skin or eyes
• Increased heart rate, chest pain or tightness in the chest
• Wheezing or shortness of breath
• Unexplained bleeding or bruising, pale skin, sore throat, high temperatore and infections
• Severe stomach pain
• Swollen ankles, problems urinating or blood in the urine
• Weak limbs, which could be a sign of stroke
• Swollen tongue, lips or face, trouble breathing, wheezing, tightness in the chest and / or a skin rash. These could indicate anaphylaxis (a severe allergic reaction) which is a medical emergency.

Contraindications

Enalapril is not suitable for everyone. Anyone who falls into one or more of the following categories should talk to their doctor before commencing or continuing treatment:  

• Pregnant women, or women who are trying to conceive
• People who are allergic to the active ingredient Enalapril, or any of the inactive ingredients, including lactose
• Patients undergoing a general anaesthetic before surgery
• People with kidney problems, or who are undergoing dialysis
• People with liver problems
• Patients with heart problems
• People who have recently suffered from a bout of vomiting or diarrhoea
• Those with low blood pressure
• Patients with a low white blood cell count
• Patients with an insect sting allergy who are undergoing desensitisation treatment.

Drug Interactions

Enalapril must not be taken with certain drugs. The following medications may interfere with the way Enalapril works, or may be less effective if taken with Enalapril:  

• Ibuprofen and other anti-inflammatory medicines
• Other medicines for treating high or low blood pressure (talk to your doctor about how these may interact)
• Medicines that may affect your blood pressure, such as antidepressants and anaesthetics
• Diuretics: these are often prescribed together with Enalapril but check to make sure they won’t affect the way it works
• Potassium supplements and other medications that alter the levels of potassium in your blood
• Drugs that suppress the immune system, such as ciclosporin and tacrolimus
• Adrenaline and other drugs to treat allergies, asthma or heart failure
• Steroid medicines
• Allopurinol
• Procainamide
• Medicines for diabetes
• Racecadotril
• Lithium.

This is not an exhaustive list, so always always talk to your doctor before taking Enalapril if you are taking any other medications or non-prescription herbal remedies.  

How to cope with Enalapril side effects

Most people won’t experience side effects when taking Enalapril, but if you do, there are some things that can help you cope.   Dizziness is a relatively common side effect when you start your medication or increase your dose. Start with a small dosage and gradually build up, to help your body get used to it, and take your dose before bed. If you do feel dizzy, stop what you are doing and find somewhere safe to lie down until you feel better.   Some people experience a dry, tickly cough when taking Enalapril. If this persists, talk to your doctor. You might be able to switch to a different type of medicine.   Headaches can be a side effect of Enalapril. If you have headaches when taking this medication, the usual advice applies; drink plenty of fluids and take a painkiller if you need to. Talk to your doctor if the headaches last for longer than a week or are particularly severe.   Some people experience diarrhoea when they take Enalapril. If this happens, drink lots of fluids but do not take any medication to treat diarrhoea without talking to your doctor first.   If you get a mild skin rash, talk to your pharmacist. They may be able to recommend an antihistamine to treat the rash.   Blurred vision is a side effect that sometimes occurs when first starting medication. If you experience this, do not drive or operate machinery. If it persists for more than a few days, speak to your doctor, as you may need to change to an alternative blood pressure medication.

Enalapril and Pregnancy

Enalapril and other ACE inhibitors are not recommended during pregnancy, especially in the second and third trimesters, due to the risk of harm to the foetus. However, high blood pressure is undesirable during pregnancy, so talk to your GP about the relative risks. You may be prescribed an alternative medication to keep your blood pressure down.

Enalapril vs other ACE inhibitors

As well as Enalapril, a number of other ACE inhibiting drugs also work in the same way to reduce high blood pressure. These include:  

• Captopril
• Cilazapril
• Fosinopril
• Imidapril
• Lisinopril
• Moexipril
• Perindopril
• Quinapril
• Ramipril
• Trandolapril

The main difference between these drugs is how long-acting they are; Captopril, for example, needs to be taken 3 times a day because its effects only last a short time, whereas Enalapril and some others can be taken just once a day.  

Dietary changes to make when taking Enalapril

You won’t need to make any significant changes to your diet when you start taking Enalapril. The only foods to avoid are those containing salt substitutes such as Lo-Salt. These salt substitutes have high levels of potassium, and when combined with Enalapril could make the levels of potassium in your blood too high.

Lifestyle changes to make when taking Enalapril

You won’t need to make many lifestyle changes when taking Enalapril, but when you first start treatment, you may feel dizzy or experience blurred vision. For this reason, it’s a good idea to take your first dose at a time when you do not need to drive, ride a bicycle or operate machinery. You should also avoid alcohol until your body adapts to the medication, because this could make the dizziness worse.

Lifestyle changes to reduce your blood pressure

If you have high blood pressure, making changes to your lifestyle can make a difference to your blood pressure and heart health. These include:

• Cut down on salt in your diet, and eat healthily. Too much salt (more than 6g per day) can raise your blood pressure
• Stop smoking. By quitting completely or even just cutting down, you can improve your heart health and reduce your blood pressure
• Reduce your alcohol intake, because drinking too much alcohol is linked with high blood pressure. Try to stay within the guidelines of 14 units or less of alcohol per week
• Be more active. Moderate, regular exercise, such as walking a few times a week, helps to regulate your blood pressure
• Manage stress. Too much pressure and stress can lead to raised blood pressure. It’s not always easy to avoid stressful situations, but having regular breaks, getting enough sleep and spending time with friends and family may help you to feel less stressed.

Enalapril vs other high blood pressure medications

ACE inhibitors are not the only type of drug available to treat high blood pressure.   Angiotensin receptor blockers (ARBs) also work to lower blood pressure and reduce the risk of heart failure by stopping Angiotensin II from narrowing the arteries. Unlike ACE inhibitors, they do this by blocking the receptor that allows Angiotensin II to work. ARBs include Candesartan, Irbesartan, Losartan and Valsartan. They may be recommended if you are experiencing a persistent dry cough as a side effect of Enalapril or other ACE inhibitors.   Calcium-channel blockers (CCBs) work by stopping calcium from narrowing the blood vessels. Because ACE inhibitors like Enalapril are less effective in over-55s and in people of Afro-Caribbean origin, CCBs may be prescribed as an alternative if you are in either of these groups.   Beta blockers reduce blood pressure by slowing down your heart rate, as well as blocking Angiotensin II. They are normally used as an alternative for people who cannot take other high blood pressure medicines, such as pregnant women.   Diuretics help lower blood pressure by relaxing the walls of the blood vessels, allowing blood to flow more easily. Like CCBs, they may be prescribed to people over 55 or of Afro-Caribbean origin, because ACE inhibitors may not be so effective for these patients. Sometimes diuretics are taken in combination with Enalapril. Enalapril combined with the diuretic hydrochlorothiazide is available under the brand name Innozide.  

Will I need to take Enalapril forever?

Yes, possibly. Enalapril is a long-term treatment to regulate your blood pressure and you may need to take it for the rest of your life.  

Is Enalapril safe for long term use?

Yes, Enalapril is designed for long term use, and most patients are advised to take it on a long term basis.   Because of the way ACE inhibitors work, Enalapril can affect the function of your kidneys. It should still be safe to take, but just to make sure, you will have regular blood tests for the duration of your treatment, to check that your kidneys are continuing to work well.  

If my blood pressure is lower can I stop taking Enalapril?

Even if your blood pressure goes down when you take Enalapril, you are likely to be advised to keep taking it. That’s because without the drug, your blood pressure could rise again. High blood pressure poses big risks to your health, including an increased risk of heart attack or stroke.  

Can I take Enalapril before surgery?

You may need to stop taking Enalapril 24 hours before you are due to undergo surgery. That’s because when combined with anaesthetic, it could make your blood pressure too low. Always tell your doctor that you are taking Enalapril if a surgical procedure is planned.

Will Enalapril affect my contraception?

No, Enalapril will not affect your contraception. If you have high blood pressure, however, you are advised against taking hormonal forms of contraception such as the combined pill and the hormonal patch. Talk to your GP about alternative options.  

Will Enalapril affect my fertility?

There are no studies linking Enalapril with a drop in fertility in either men or women. If you are trying to conceive, it’s a good idea to discuss this with your GP and follow their advice, because Enalapril is not normally recommended during pregnancy.    

Sources

• Patient Information Leaflet
• NHS > Enalapril
• British Heart Foundation > ACE Inhibitors
• Blood Pressure UK > ACE Inhibitors
• Your Hormones > Angiotensin
• JACC Heart Failure > Can Vaccinations Improve Heart Failure Outcomes?
• Canadian Family Physician > Taking ACE inhibitors during early pregnancy

Will Enalapril help anxiety?

If you have a stressful and anxious lifestyle, this may affect your blood pressure. Enalapril will bring down your blood pressure, but this in itself may not help you to feel less anxious. Speak to your GP or therapist if you are concerned about anxiety.