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  1. About cyclizine
  2. Key facts
  3. Who can and cannot take cyclizine
  4. How and when to take it
  5. Side effects
  6. How to cope with side effects
  7. Pregnancy and breastfeeding
  8. Cautions with other medicines
  9. Common questions

1. About cyclizine

Cyclizine is an anti-sickness medicine. It's used to help stop you feeling or being sick (nausea or vomiting).

You can take cyclizine to treat morning sickness, vertigo and travel sickness.

It can also be taken to treat sickness caused by general anaesthetics after surgery, cancer treatment or other medicines, and some inner ear problems such as Ménière's disease.

2. Key facts

  • Avoid drinking alcohol while taking cyclizine. Alcohol increases the risk of side effects.
  • Cyclizine can be taken by most adults and children aged 6 years and over.
  • Common side effects include feeling sleepy and blurred vision.
  • You can usually take cyclizine when you need it, up to 3 times a day.
  • Cyclizine used to be known by the brand name Valoid.

3. Who can and cannot take cyclizine

Cyclizine can be taken by most adults and children aged 6 years and over.

Cyclizine is not suitable for some people. Tell your doctor or pharmacist if you:

  • have had an allergic reaction to cyclizine or any other medicines in the past
  • have an eye disease called glaucoma
  • have problems peeing or emptying your bladder
  • have a condition that can lead to bowel obstruction, such as Crohn's disease, diverticulitis, hernias or colon cancer
  • have liver problems
  • have epilepsy or any condition that causes fits
  • have high blood pressure or heart failure
  • have a tumour called phaeochromocytoma
  • have an intolerance to or cannot absorb some sugars, such as lactose or sorbitol
  • have a serious blood disorder called porphyria
  • are due to have an allergy test - cyclizine can affect your results, so you may need to stop taking it a few days before your test; ask the clinic where you're due to have your allergy test

4. How and when to take it

If you or your child have been prescribed cyclizine, follow your doctor's instructions about how and when to take it.

You can take cyclizine with or without food.

How much to take

You can usually take cyclizine when you need it.

The usual dose for:

  • adults and children aged 12 years and over is 50mg
  • children aged 6 to 11 years is 25mg

It can be taken up to 3 times a day, 8 hours apart if needed.

For travel sickness, take cyclizine 1 to 2 hours before travel. If you're going on a long journey, you can take another dose after 8 hours, and 1 more after another 8 hours if needed.

If you need to give a 25mg dose, the 50mg tablet has a score line so you can break it in half into 2 equal doses.

What if I forget to take it?

For travel sickness, take it as soon as you remember.

For anything else, skip the missed dose and take your next dose at the usual time.

Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.

What if I take too much?

Too much cyclizine can be dangerous.

If you have accidentally taken too much, you may:

  • feel very sleepy
  • have a very fast, uneven or pounding heartbeat (palpitations)
  • have breathing problems
  • have fits and become unconscious

If your child takes too much cyclizine, they may also:

  • move unsteadily or stumble
  • have uncontrolled movements, especially in their hands or feet
  • see or hear things that are not there (hallucinations)
  • have an uneven heartbeat

Immediate action required: Call 999 or go to A&E straight away if you take too much cyclizine

If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.

Take the cyclizine packet, or the leaflet inside it, plus any remaining medicine with you.

5. Side effects

Like all medicines, cyclizine can cause side effects, although not everyone gets them.

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

They're usually mild and go away by themselves:

  • feeling drowsy
  • blurred vision
  • dry mouth
  • headache
  • constipation

Serious side effects

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

Tell your doctor straight away if you get:

  • muscle stiffness or shaking, or unusual face or tongue movements
  • any bleeding that's very bad or you cannot stop, such as cuts or nosebleeds that do not stop within 10 minutes
  • yellowing of the skin or whites of the eyes - these can be signs of liver problems

Serious allergic reaction

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

Immediate action required: Call 999 or go to A&E 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 cyclizine.

For a full list, see the leaflet inside your medicine packet.


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

6. How to cope with side effects

What to do about:

  • feeling drowsy - do not drive or use tools or machinery if you're feeling this way. Do not drink alcohol, as it'll make you feel more tired. If this does not help, talk to your doctor. They may suggest a different anti-sickness medicine.
  • blurred vision - do not drive or use tools or machinery while this is happening. If it lasts for more than 2 days, speak to your doctor.
  • dry mouth - try chewing sugar-free gum or sucking sugar-free sweets.
  • headache - rest and drink plenty of fluids. You can take an everyday painkiller like paracetamol or ibuprofen. Talk to your doctor if the headaches last longer than a week or are severe.
  • constipation - eat more high-fibre foods, such as fresh fruit and vegetables and cereals. Try to drink several glasses of water or another non-alcoholic liquid each day. If you can, it may also help to do some gentle exercise.

7. Pregnancy and breastfeeding

Your doctor may prescribe cyclizine for morning sickness when other treatments have not worked.

There's no evidence that cyclizine will harm your unborn baby, but for safety it's best to take it for the shortest possible time.

For more information about how cyclizine can affect you and your baby during pregnancy, read the leaflet about the best use of medicines in pregnancy (BUMPS).

Cyclizine and breastfeeding

Cyclizine passes into breast milk in small amounts. Talk to your doctor, as other medicines might be better while you're breastfeeding.

If your baby was premature, had a low birth weight or has health problems, speak to your doctor before taking any anti-sickness medicine.

If you take cyclizine and notice your baby's sleeping more than usual, talk to your health visitor or doctor as soon as possible.

8. Cautions with other medicines

Some medicines and cyclizine interfere with each other and increase the chance of having side effects.

Tell your pharmacist or doctor if you're taking:

  • a type of antidepressant called a monoamine oxidase inhibitor, such as phenelzine
  • any medicine that makes you drowsy, gives you a dry mouth or makes it difficult for you to pee - taking cyclizine might make these side effects worse

Is it safe to take with other anti-sickness medicines?

It's usually best to only take 1 type of medicine for feeling or being sick.

If cyclizine does not work for you, speak to your doctor and they may suggest a different medicine for you.

Mixing cyclizine with herbal remedies

Some herbal remedies can make your side effects worse. Speak to your pharmacist before taking any herbal supplements.


Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.

9. Common questions

How does cyclizine work?

There's an area in your brain called the vomiting centre, which controls when you feel or be sick.

The vomiting centre is triggered when your brain releases a chemical called histamine.

It's also triggered when it receives messages from an area of the brain called the chemoreceptor trigger zone (CTZ).

Cyclizine blocks histamine and the messages sent in your brain that make you feel or be sick.

How long does it take to work?

Cyclizine starts to work after 30 minutes of taking it. You should feel better after 1 to 2 hours.

It should work for about 4 to 6 hours.

How long will I take it for?

How long you take cyclizine for depends on why you're taking it.

For travel sickness or after surgery, you may only need to take cyclizine for a day or two.

You may need to take cyclizine for longer if you're taking it to prevent symptoms - for example, to stop sickness after cancer therapy or if you have some inner ear problems, such as Ménière's disease.

Talk to your doctor or pharmacist if you're unsure how long you need to take cyclizine for.

Is it safe to take long term?

Cyclizine is unlikely to do you any harm if you take it for a long time.

But it's best to only take cyclizine for as long as you need to.

Is cyclizine addictive?

It's unlikely that you'll get addicted to cyclizine.

But it's best to only take cyclizine for as long as you need to.

How does cyclizine compare to other similar medicines?

Cyclizine is a type of drowsy (sedating) antihistamine, as it can make you feel sleepy.

There are other drowsy antihistamines that can help with feeling or being sick, such as promethazine and cinnarizine.

Both cyclizine and cinnarizine are less likely to make you feel sleepy than promethazine.

There's not enough information available to say whether one is better than another for helping with sickness.

There are also other medicines that can help with sickness, such as metoclopramide, ondansetron and domperidone.

You may need to try a few different medicines to find out what works best for you.

Ask your pharmacist or doctor for advice if you're unsure.

Are there other ways to treat morning sickness?

Most cases of feeling and being sick in pregnancy pass after 16 to 20 weeks.

If your morning sickness is not too bad, there are some lifestyle changes you can make to help.

Find out ways to help morning sickness in pregnancy

Although cyclizine has not been officially approved for treating morning sickness, it's considered to be a useful and safe medicine to use in pregnancy.

Can I drink alcohol with it?

Do not drink alcohol while you're taking cyclizine.

Alcohol and cyclizine together can make you sleep very deeply. It may affect your breathing and you may have difficulty waking up.

Are there foods and drinks to avoid?

You can eat and drink normally while taking cyclizine.

Will it affect my contraception?

Cyclizine does not affect any type of contraception, including the combined pill and emergency contraception.

But if cyclizine is not working for you and you're being sick, your contraceptive pills may not protect you from pregnancy.

Look at the pill packet to find out what to do.

Will it affect my fertility?

Cyclizine does not affect male or female fertility.

Can I drive or ride a bike?

Do not drive a car or ride a bike if cyclizine makes you sleepy, gives you blurred vision, or makes you feel dizzy, clumsy or unable to concentrate or make decisions.

This may be more likely when you first start taking cyclizine, but could happen at any time (for example, when starting another medicine).

It's an offence to drive a car if your ability to drive safely is affected.

It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.

GOV.UK has more information on the law on drugs and driving.

Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking cyclizine.

Can lifestyle changes help prevent me feeling or being sick?

There are some lifestyle changes that can help with feeling or being sick:

  • stick to simple meals and try not to eat rich or spicy foods - having smaller, more frequent meals can help
  • avoid drinking with meals - drinking any liquids with meals may increase feelings of fullness, which makes feeling sick worse
  • eat foods or drinks containing ginger - this is a popular natural remedy commonly used to stop feeling sick
  • avoid strong smells - these may make you feel worse
  • stay hydrated - drink plenty of fluids, such as water, and taking small sips often may help

Useful resources

Page last reviewed: 8 March 2019
Next review due: 8 March 2022