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 production 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 production is 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 it has the full effect. 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. 

Please note: different generic brands of enalapril could contain different inactive ingredients than those listed here.

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 20mg once a day. The usual dosage for heart failure is one 10-20mg 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 or split?

Enalapril is available in tablet or liquid form. If you wish to make the medicine more palatable by mixing it with food, you can either use a liquid form, or the tablet can be crushed. Always use the measuring spoon provided when measuring out a liquid dose of enalapril.

Enalapril side effects

Like all medications, enalapril can cause side effects. If you experience any of the serious side effects listed below, stop taking enalapril and seek immediate medication attention: 

• An allergic reaction to enalapril, which may include swelling of the face, lips or throat, breathing difficulty, itch or rash
• Severe skin reaction, including rash, mouth ulcers, or blistering
• Yellow skin or eyes – this can be a sign of liver problems
• Severe stomach pain – this can be pancreatitis
• Unprovoked bleeding or bruising, catching infections more easily, or feeling tired – this can indicate a blood disorder
• Fast or irregular heart rate, chest pain or tightness – this can be signs of a heart problem
• Shortness of breath, wheezing or a persistent cough – this can indicate a lung problem
• Passing less urine than normal – this can be a sign of kidney problems
• Sudden weakness or problems speaking – this can be a stroke

Common side effects (affecting up to 1 in 10 people) include:

• Dry cough
• Dizziness
• Faints due to low blood pressure
• Headache
• Nausea or vomiting
• Diarrhoea or constipation
• Mild skin rash
• Blurred vision
• Hair loss
• Sinusitis or bronchitis
• Dry mouth
• Breathlessness
• Stomach upset or gut pain
• Chest pain or angina
• Muscle pain or cramps
• Blood tests showing more potassium than usual in the blood
• Angioedema (rapid swelling of the skin)
• Palpitations or an irregular heartbeat
• Fatigue
• Drowsiness
• Sensory changes e.g. pins and needles or numbness
• Changes in kidney function
• Runny nose
• Sleep disorders
• Altered taste
• Tinnitus (ringing in the ears)
• Depression
• Hypersensitivity

Uncommon side effects can affect up to 1 in 100 people and include:

• Joint pain
• Confusion
• Erectile dysfunction
• Fever
• Anaemia
• Hyperhidrosis (increased sweating)
• Heart attack 
• Pancreatitis
• Peripheral oedema (swelling in the hands or feet)
• Sensitivity to sunlight
• Respiratory (lung) disorders
• Stroke
• Decreased appetite
• Worsening of asthma
• Hoarse voice
• Low blood sugar
• Tiredness
• Nervousness
• Sleep disorders
• Throat pain
• Running nose

The following rare side effects can affect up to 1 in 1,000 people:

• Blood tests showing a decrease in red blood cells, white blood cells, platelets or haemoglobin
• Hepatitis (liver inflammation)
• Stevens-Johnson syndrome (a red rash typically causing blisters)
• Gynaecomastia (breast enlargement in men)
• Liver disorders
• Swollen glands
• Raynaud’s phenomenon
• Toxic epidermal necrolysis (a serious blistering skin condition)

Other side effects (frequency not known)

• Arthritis
• Inflammation of the muscles
• Vasculitis (inflammation of the vessels, causing rash)
• Syndrome of inappropriate ADH (a problem with the regulation of urine output)

Contraindications

Do NOT take enalapril if you:

• Are allergic to any of the ingredients in this medication
• Have a history of angioedema, a severe allergic reaction that includes itching, hives, red marks on the hands, feet and throat, swelling around the eyes or lips, difficulty breathing and swallowing
• Are pregnant or breastfeeding

Before taking enalapril, tell your doctor if any of the following applies to you:

• You have heart problems including cardiomyopathy and valvular heart disease
• You have liver problems
• You have kidney problems, including if you are having dialysis
• You have diabetes 
• You are of black African or Caribbean origin
• You have any problem with the salts in your blood (e.g. potassium, sodium)
• You have lost a lot of salts or fluids through vomiting, diarrhoea, sweating more than usual, being on a low-salt diet, taking diuretics or having dialysis
• You have primary aldosteronism
• You are going to receive an anaesthetic
• You might become pregnant
• Your blood pressure is abnormally low or unstable
• You have severe or symptomatic aortic stenosis
• You are having desensitization treatment for wasp stings
• You have a collagen vascular disease such as scleroderma or systemic lupus erythematosus
• You have peripheral vascular disease or generalised atherosclerosis

Drug interactions

Before taking enalapril, tell your doctor if you are taking any other medicines, including those purchased over the counter without a prescription. 

In particular, tell your doctor if you are taking any of the following:

• Angiotensin receptor blockers (ARB) e.g. Candesartan, Lorsaran
• Calcium channel blockers e.g. Amlodipine
• Aliskiren
• Anti-inflammatory medicines such as Ibuprofen 
• Diuretics e.g. Indapamide, Bendroflumethiazide, Furosemide
• Allopurinol 
• Bee/wasp venom extracts
• Antacids
• Amiloride
• Eplerenone
• Heparins
• Potassium salts
• Trimethoprim
• Medicines for heart rhythm such as Digoxin or Procainamide
• Alpha-blockers e.g. Doxasocin 
• Medicines for diabetes e.g. Insulin, Metformin, and Sulfonylureas
• Lithium
• Steroid medicines for inflammation such as prednisolone
• Sacubitril/valsartan for treatment of long-term chronic heart failure
• Medicines used for the treatment of low blood pressure, shock, cardiac failure, asthma or allergies such as ephedrine, noradrenaline or adrenaline
• Chemotherapy medicines
• Medicines to stop the rejection of organs after surgery such as Ciclosporin, Temsirolimus, Sirolimus, Everolimus
• Spironolactone
• Racecadotril

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, 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 inhibitor drugs that 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 wnalapril and some others can be taken just once a day.

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 vascular constriction. 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 altering water balance. 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 for example enalapril combined with the diuretic hydrochlorothiazide is available under the brand name Innozide, and perindopril with indapamide is sold as Coversyl Arginine Plus. 

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.

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.

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.

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 if you are at risk of lowered kidney function.

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.