Experiences with
Diltiazem

Diltiazem is a medicine used to treat high blood pressure.

If you have high blood pressure, taking diltiazem helps to prevent coronary heart disease, heart attacks and strokes.

It works by lowering your blood pressure and making it easier for your heart to pump blood around your body.

Diltiazem is also used to:

prevent chest pain caused by angina
reduce the frequency of attacks in Raynaud's phenomenon
help heal an anal fissure

Diltiazem is available on prescription only. It comes as tablets or capsules to treat high blood pressure, angina or Raynaud's. It's also available as a cream or ointment to treat anal fissures.

Who can take diltiazem

Most adults and children aged 12 years old and over can take diltiazem.

Who may not be able to take diltiazem

Diltiazem is not suitable for some people.

To make sure it's safe for you, tell your doctor if you:

have ever had an allergic reaction to diltiazem or any other medicine
are pregnant, trying to get pregnant or breastfeeding
have liver disease or kidney disease
have heart failure or problems with your heartbeat
have a condition that causes food to move slower than usual through your body
have a rare inherited condition called porphyria

Dosage

Your dose of diltiazem depends on why you need the medicine and what kind your doctor has prescribed. It's important to keep taking the same brand of diltiazem once you have started.

Diltiazem tablets or capsules come as standard or slow-release. Your doctor will tell you whether you need to take them once a day or in divided doses throughout the day.

Slow-release tablets and capsules release diltiazem slower than the standard tablets and capsules.

Changes to your dose

If the dose you start on does not reduce your blood pressure enough or help to control your angina, then your doctor will gradually increase your dose.

Your doctor may also lower your dose if side effects bother you.

How to take tablets or capsules

You can take diltiazem with or without food. Swallow diltiazem tablets or capsules whole, usually with a glass of water. Do not chew or crush them.

If you find tablets or capsules difficult to swallow, speak to a pharmacist or doctor, as there may be other options.

You can take diltiazem at any time of day but try to make sure it's around the same time or times every day.

With some of the capsules and tablets you might notice what looks like a whole capsule or tablet in your poo. Do not worry, this is normal. It's just the empty outer shell of the capsule or tablet which your body does not digest.

How to use cream or ointment

For an anal fissure, you'll need to apply a 2.5cm length of diltiazem cream or ointment to the broken skin on your anus, twice a day, usually for 6 to 8 weeks. Follow the instructions on the packaging.

How long to take it for

If you're taking diltiazem for high blood pressure or angina, you'll usually take it long term, even for the rest of your life.

Talk to your doctor if you want to stop taking diltiazem. Stopping may cause your blood pressure to rise and this may increase your risk of a heart attack or stroke.

If you're using it to treat an anal fissure, you'll use the cream or ointment to heal the tear on your anus until it's no longer painful to poo. This will mean the tear has healed. This usually takes around 6 to 8 weeks.

If you stop using the cream before a fissure has fully healed, it may tear again.

If you're bothered by side effects, your doctor may be able to prescribe you a different medicine.

Keep taking diltiazem even if you feel well, as you'll still be getting the benefits of the medicine.

If you forget to take a dose and you usually take diltiazem:

once a day – take it as soon as you remember, unless it's less than 12 hours until your next dose. In this case, skip the missed dose and take your next dose at the usual time
twice a day – take it as soon as you remember, unless it's less than 4 hours until your next dose. In this case, skip the missed dose and take your next dose at the usual time
3 times a day – skip the missed dose and take your next dose at the usual time

Never have an extra dose to make up for a forgotten one.

If you forget doses often, it may help to set an alarm to remind you. You could also ask a pharmacist for advice on other ways to help you remember to take your medicine.

If you take too much

Too much diltiazem can make you feel faint, dizzy or sleepy. This is because it can cause your heart to beat irregularly.

you take more than your prescribed dose of diltiazem

Go to 111.nhs.uk or call 111

If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.

Bring the diltiazem packet or leaflet inside it, any remaining medicine, and any other medicines you take.

Common side effects

These common side effects of diltiazem happen in more than 1 in 100 people. They are usually mild and will not last long. There are things you can do to help cope with them:

Raise your legs or the swollen area on a chair or pillows when you can.

This will get better after a few days as your body gets used to the medicine. If it does not, or it gets worse, speak to your doctor.

Make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask a pharmacist to recommend a painkiller. Paracetamol is safe to take with diltiazem.

Headaches usually go away after the first week of taking diltiazem. Talk to your doctor if they last longer than a week or are severe.

If diltiazem makes you feel dizzy, stop what you're doing and sit or lie down until you feel better. Do not drive, ride a bike or operate tools or machinery until you feel OK. Do not drink alcohol as it will make you feel worse.

Make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Try to take diltiazem at a time when you can sit down (or lie down) when the symptoms are at their worst.

If you're still having problems after a week, speak to your doctor, as they may need to change you to a different type of medicine.

Do not drive, cycle or use tools or machinery until you feel OK.

Try cutting down on coffee, tea and alcohol. It might help to keep the room cool and use a fan. You could also spray your face with cool water or sip cold or iced drinks.

The flushing should go away after a few days. If it does not go away or it's causing you problems, contact your doctor.

Try holding something cool on your skin like a damp towel. Take cool baths or showers. If you have itchy skin, use an unperfumed moisturiser regularly. However, do not use moisturiser on an anal fissure as this will irritate it more.

Keep your nails clean, short and smooth and try to pat or tap your skin rather than scratching.

Try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help.

If you're in a lot of pain, speak to a doctor or pharmacist.

It might help to eat smaller and more frequent meals, and to eat and drink slowly. Talk to your doctor if the symptoms get worse.

Get more fibre into your diet such as fresh fruit, vegetables and cereals, and drink plenty of water. Try to exercise regularly, for example, by going for a daily walk or run. If this does not help, talk to a pharmacist or doctor.

Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Serious side effects

Serious side effects after taking diltiazem are rare and happen in less than 1 in 10,000 people.

Stop taking diltiazem and call a doctor or call 111 now if:

you get severe pain in your stomach
the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on brown or black skin – this can be a sign of liver problems
your heartbeat becomes noticeable (palpitations)

you get chest pain that does not stop after a few minutes or is new or worse if you already have angina

Chest pain is a possible sign of a heart attack and needs to be checked out as soon as possible.

Meds - serious side effects A&E safety messaging

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to diltiazem.

Meds New IA (H4) - serious allergic reaction

These are not all the side effects of diltiazem. For a full list, see the leaflet inside your medicine packet.

Diltiazem and pregnancy

You can use diltiazem during pregnancy, although it's not usually recommended.

If you're taking diltiazem to treat high blood pressure, you might be switched to a different medicine if you're pregnant.

If you're taking diltiazem for angina or heart rhythm problems, you should be reviewed by a pregnancy specialist (obstetrician) and a heart specialist (cardiologist). Keep taking diltiazem until you've had your review.

If you're using diltiazem to treat anal fissures, speak to your doctor who may suggest an alternative medicine.

Diltiazem and breastfeeding

If your doctor or health visitor says your baby is healthy, you can take diltiazem while breastfeeding.

There is not much information about using diltiazem while breastfeeding, but some information shows that it passes into breast milk in tiny amounts. It's unlikely to harm your baby. However, your doctor might suggest an alternative medicine that we know more about.

If you use the cream or ointment, make sure that you've washed your hands before picking up your baby.

If you do breastfeed while taking diltiazem and you notice that your baby is not feeding as well as usual, seems unusually sleepy, looks paler than usual, or if you have any other concerns about your baby, then talk to your health visitor midwife, pharmacist or doctor as soon as possible.

Diltiazem and fertility

Diltiazem may affect male fertility. There's no evidence that diltiazem affects fertility in women.

If you're trying for a baby, or having problems getting pregnant while taking diltiazem, then speak to your doctor.

Meds New IA (H2) - Pregnancy non-urgent care card

Cautions with other medicines

There are some medicines that may affect how diltiazem works.

Taking diltiazem with other medicines that lower blood pressure can sometimes lower your blood pressure too much. This may make you feel dizzy or faint. If this happens to you, tell your doctor, as your dose may need to be changed.

Tell your doctor or pharmacist before starting diltiazem if you're taking:

antibiotics such as clarithromycin, erythromycin or rifampicin
antifungal medicines such as itraconazole or ketoconazole
medicines to treat HIV or HCV (hepatitis C virus)
medicines to treat epilepsy, such as carbamazepine or phenytoin
medicines to suppress your immune system, such as ciclosporin or tacrolimus
more than 20mg a day of simvastatin, a medicine used to lower cholesterol

Taking diltiazem with painkillers

Paracetamol is the best painkiller to take while you're taking diltiazem. If paracetamol does not work, try ibuprofen.

Talk to your doctor if you need to take painkillers more than a few times a week.

Mixing diltiazem with herbal remedies or supplements

St John's wort is a herbal remedy taken for depression. It's thought to affect the way diltiazem works.

Talk to a pharmacist or doctor if you're thinking about taking St John's wort.

There's not enough information to say that other complementary medicines, herbal remedies and supplements are safe to take with diltiazem. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

Meds New IA (H2) - Cautions with other medicines alert