Digoxin - EM Doctors

1. About digoxin

Digoxin is a type of medicine called a cardiac glycoside.

It’s used to control some heart problems, such as irregular heartbeats (arrhythmias) including atrial fibrillation.

It can also help to manage the symptoms of heart failure, usually with other medicines.

Digoxin is only available on prescription.

It comes as tablets and as a liquid (sometimes called an elixir). It can also be given as an injection, but this is usually done in hospital.

2. Key facts

Digoxin slows down your heart rate and makes it easier for your heart to pump blood around your body.
It's usual to take digoxin once a day and it's best if you take it at the same time each day.
Common side effects include feeling confused, dizzy, feeling or being sick, loss of appetite, diarrhoea, changes in your vision or skin rashes.
Digoxin is usually recommended with other heart medicines when these medicines have not been enough to control your symptoms on their own.
It's also known by the brand name Lanoxin.

3. Who can and cannot take digoxin

Digoxin can be taken by adults. It's sometimes prescribed for children if a heart specialist recommends it.

It is not suitable for everyone. Check with your doctor before you start taking digoxin if you have:

had an allergic reaction to digoxin or any other medicine in the past
serious heart problems such as cardiomyopathy, Wolff-Parkinson-White syndrome, heart block, pericarditis, myocarditis, any problems with arrhythmias or you have recently had a heart attack
kidney problems
an overactive thyroid (hyperthyroidism) or an underactive thyroid (hypothyroidism) – changes in how the thyroid works can affect how digoxin works
stomach or bowel problems, such as Crohn's disease, or if you have had surgery on your bowel or stomach – these can affect how much digoxin gets into your body and may change the dose of digoxin you need
lung disease or severe asthma
a rare hereditary problem of galactose intolerance (including the Lapp lactase deficiency or glucose-galactose malabsorption)
beriberi disease (also known as thiamine deficiency)
a low blood potassium or magnesium level, or a high blood calcium level

4. How and when to take it

You can take digoxin with or without food, but it's best to take it at the same time each day.

Most people take it in the morning after breakfast. You'll usually take it once a day.

Swallow the tablets whole with a drink of water.

If you are using the liquid, it's important to measure your dose using the syringe (pipette) that comes with the medicine. Do not dilute the liquid.

Dosage

The first time you take digoxin you may be asked to take several tablets (or amounts of liquid) as a single dose – this is called the "initial dose".

Your doctor will do a blood test after the initial dose to see how it's worked for you. They'll then recommend a daily dose. Sometimes this will be split into doses to take throughout the day.

After the initial dose, the usual daily dose for adults and children over 10 years is 125 micrograms to 250 micrograms daily.

Doses are usually lower for people over 65 years and for people with kidney disease, as they may be more likely to get side effects.

For babies and children under 10 years, the doctor will use the child's weight and age to work out the right dose for them.

What if I forget to take it?

If you miss a dose of digoxin, leave out that dose and take your next dose at the usual time. Do not take a double dose to make up for the forgotten dose.

If you often forget doses, it may help to set an alarm to remind you.

A pharmacist can give you advice on other ways to remember your medicine. Let your doctor know too, as it may affect your heart.

What if I take too much?

The amount of digoxin that can lead to an overdose varies from person to person. Children and older people may be more affected by the effects of too much digoxin.

If you have taken too much digoxin, your doctor may ask you to have a blood test to see how much digoxin is in your blood and to check if your kidneys are working properly.

You may also be asked to have an electrocardiogram (ECG) to see the effect on your heartbeat.

Call a doctor straight away if you take too much digoxin.

Urgent advice: Call 111 for advice now if:

you take too much digoxin and you feel unwell
you take too much digoxin and you are over 65 or have kidney problems (even if you feel well)
a child has taken too much digoxin (even if they feel well)

If you need to go to A&E, take the digoxin packet, or the leaflet inside it, plus any remaining medicine with you.

5. Side effects

Like all medicines, digoxin can cause side effects.

Some people are more sensitive to the effects of digoxin than others. These include children, older people, people with kidney disease or an underactive thyroid (hypothyroidism).

Common side effects

These common side effects happen in more than 1 in 100 people.

Talk to your doctor or pharmacist if these side effects bother you or last longer than a few days:

feeling confused, dizzy or generally unwell
feeling or being sick (nausea or vomiting) and loss of appetite
diarrhoea
changes in your vision (including blurred vision and not being able to look at bright light)
skin rashes

Important

Tell your doctor if you have more than 2 of the common side effects – it means you could have too much digoxin in your blood.

Serious side effects

It happens rarely, but some people have serious side effects after taking digoxin.

Tell your doctor straight away if you:

have more than 2 of the common side effects – it means you could have too much digoxin in your blood
have a fast heart rate (palpitations), shortness of breath, feel dizzy or lightheaded and are sweating

Serious allergic reaction

It's possible to have a serious allergic reaction (anaphylaxis) to digoxin.

Immediate action required: Call 999 or go to A&E now if:

you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
you're wheezing
you get tightness in the chest or throat
you have trouble breathing or talking
your mouth, face, lips, tongue or throat start swelling

You could be having a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of digoxin. For a full list see the leaflet inside your medicines packet.

You can report any suspected side effects to the UK safety scheme.

6. How to cope with side effects

What to do about:

feeling confused, dizzy or generally unwell – if digoxin makes you feel dizzy, lie down so that you do not faint, then sit until you feel better. Do not drive, ride a bike or use tools or machines until you feel better.
feeling or being sick (nausea or vomiting) and loss of appetite – stick to simple meals and do not eat rich or spicy food. Drink plenty of fluids, such as water or squash, to avoid dehydration. If you're being sick, take small, regular sips of water. If you have heart failure you may need to be careful about how much you drink - (ask your doctor how much is ok).
diarrhoea – drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor. If you have heart failure you may need to be careful about how much you drink - (ask your doctor how much is ok).
changes in your vision – do not drive, ride a bike or use tools or machinery until these symptoms stop.
skin rashes – ask a pharmacist or doctor if they can recommend something to help.

7. Pregnancy and breastfeeding

Digoxin and pregnancy

Digoxin is not thought to be harmful during pregnancy, but it's not possible to be certain.

It's important to treat a heart condition when you're pregnant and this will help your baby to stay healthy.

If your doctor recommends digoxin during your pregnancy, they'll prescribe the lowest dose that works for you.

If there is too much digoxin in your blood, it could affect your baby. Your doctor may do blood tests to check that the level of digoxin in your blood is OK. If there is too much digoxin in your blood, your doctor may reduce your daily dose of digoxin.

If you're trying to get pregnant or you're already pregnant, talk to your doctor about the benefits and possible harm from taking digoxin.

It will depend on the reason you need to take it, how many weeks pregnant you are and what other treatments are an option for you.

Digoxin and breastfeeding

If your doctor or health visitor says that your baby is healthy, it's OK to take digoxin while breastfeeding.

Digoxin passes into breast milk in very small amounts. It's unlikely to cause any side effects in your baby.

If you notice that your baby is not feeding as well as usual, seems unusually sleepy, or if you have any other concerns about your baby, talk to a health visitor or doctor.

Non-urgent advice: Tell your doctor if you're:

trying to get pregnant
pregnant
breastfeeding

8. Cautions with other medicines

Some medicines can interfere with the way digoxin works or can increase the risk of side effects.

Tell your doctor if you're taking:

medicines used to treat an irregular heartbeat (arrhythmia), heart conditions or high blood pressure such as amiodarone, verapamil or diltiazem
medicines that make you pee more (diuretics) such as furosemide
medicines to treat bacterial or fungal infections, such as tetracycline, clarithromycin, erythromycin, rifampicin, trimethoprim or itraconazole
medicines for arthritis, including ibuprofen, diclofenac, indomethacin, hydroxychloroquine and chloroquine
medicines to treat HIV, such as atazanavir, darunavir, ritonavir and saquinavir

Some medicines that you can buy from a pharmacy or shop can affect with the way digoxin works.

Ask a pharmacist for advice before using antacids, kaolin (for stomach upsets) or laxatives (for constipation).

Do not take non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen regularly without checking with your doctor first.

Mixing digoxin with herbal remedies or supplements

There's very little information about taking herbal remedies and supplements with digoxin.

The herbal remedy St John's wort can interfere with how digoxin works. Tell a pharmacist or doctor if you are using this or thinking about using it.

Important

For safety, tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions

How does digoxin work?

How long does it take to work?

How will I know if it's working?

If you have atrial fibrillation, or certain heart problems such as arrhythmia, you may notice improvements after a few weeks.

If you have atrial fibrillation, the following symptoms may mean that digoxin is not working as well as it could be:

a fast pulse
a fast heart beat (palpitations)
you feel dizzy, faint or have fainted

If you have heart failure, the following symptoms may mean that digoxin is not working as well as it could be:

more shortness of breath than usual
you cannot climb stairs or walk as easily as usual
you are waking up short of breath at night, or if you need more pillows than usual
you need to pee more at night
your ankles appear swollen or your shoes feel too tight

If you get any of these symptoms, your doctor will decide how to change your dose.

How long will I take digoxin for?

Is digoxin safe to take?

Digoxin is a very effective medicine, but it can have serious side effects. It's important to take it as your doctor has recommended.

It is safe to take as long as the benefits of taking it are greater than the risks – your doctor will help you decide this.

Your doctor will check your dose is right and you will be asked to have blood tests.

It's important to let your doctor know if you have any new symptoms or symptoms that get worse.

Do I need to have regular blood tests if I'm taking digoxin?

You will have regular blood tests to check that your kidneys are healthy (because they remove digoxin from the body, so it's important they work properly).

Your blood test may also check that you have the right amounts of potassium, magnesium and calcium in your blood. If there's too much or too little of these in your blood it can affect how digoxin works.

The dose of digoxin is important as too little will not help, but too much can cause side effects. To make sure your dose is right, you doctor will ask you to have a blood test.

This must be done at least 6 hours after your last dose of digoxin, so you'll need to tell your doctor or nurse when you normally take your digoxin.

They may want you to wait to take your dose or they may schedule your appointment so that you will have your blood taken at the right time.

What will happen if I stop taking it?

Talk to your doctor if you want to stop taking digoxin. Stopping digoxin suddenly can make your condition worse.

If you have side effects, it's important that you talk to your doctor about this. Your doctor may be able to prescribe a different medicine for your heart problems.

If you stop taking digoxin, it will take about 8 days for it to be completely out of your body. It could take longer if you have kidney problems.

How does it compare with other heart medicines?

Digoxin is a type of medicine called a cardiac glycoside and it's the only medicine of its kind.

Digoxin is used much less commonly now than in the past because newer, more effective medicines for heart failure and certain heart problems, such as arrhythmia and atrial fibrillation, are now available.

Some of the main medicines for heart failure include:

ACE inhibitors
angiotensin receptor blockers (ARBs) such as valsartan
beta blockers
spironolactone or eplenerone
medicines which make you pee more (diuretics) such as furosemide
ivabradine, sacubitril, and hydralazine with nitrate

Some of the medicines which help to control heart rate include:

beta blockers, such as bisoprolol or atenolol
calcium channel blockers, such as verapamil or diltiazem

They all work differently to digoxin and the side effects can also be different.

Your heart specialist might prescribe digoxin for you to use alongside your other heart medicines when these are not enough to manage your symptoms.

You may need to try a few different medicines before you find a combination that controls your symptoms but does not cause unpleasant side effects.

Will I need to stop digoxin before surgery?

Is there any food or drink I need to avoid?

Can I drink alcohol?

Will it affect my contraception?

Will it affect my fertility?

Will it affect my sex life?

Can I drive or ride a bike?

Can lifestyle changes help?

You can boost the health of your heart by making some key lifestyle changes.

Quit smoking – smoking increases your heart rate and blood pressure. Quitting smoking brings down your blood pressure and relieves heart failure symptoms. Try to avoid second-hand smoke.

Cut down on alcohol – it's a good idea to not drink alcohol when you first start taking digoxin, or after a dose increase, until you see how the medicine affects you. If you find digoxin makes you feel dizzy, it's best to stop drinking alcohol. If you do drink, keep to the recommended guidelines of no more than 14 units of alcohol a week. A standard glass of wine (175ml) is 2 units. A pint of lager or beer is usually 2 to 3 units of alcohol.

Exercise – regular exercise lowers blood pressure by keeping your heart and blood vessels in good condition. It does not need to be intense; walking every day will help.

Eat well – aim to eat a diet that includes plenty of fruit and veg, wholegrains, fat-free or low-fat dairy products and lean proteins. It's a good idea to cut down on salt too. Eating too much salt is the biggest cause of high blood pressure. The more salt you eat, the higher your blood pressure will be. Aim for no more than 6g of salt a day.

Deal with stress – when you're anxious or upset, your heart beats faster, you breathe more heavily and your blood pressure often goes up. This can make heart failure worse too. Find ways to reduce stress in your life. To give your heart a rest, try napping or putting your feet up when possible. Spend time with friends and family to be social and help avoid stress.