Digoxin is a type of medicine called a cardiac glycoside.
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.
- 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.
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
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.
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.
If you need to go to A&E, take the digoxin packet, or the leaflet inside it, plus any remaining medicine with you.
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
- changes in your vision (including blurred vision and not being able to look at bright light)
- skin rashes
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.
These are not all the side effects of digoxin. For a full list see the leaflet inside your medicines packet.
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.
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.
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.
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.