Fluconazole: medicine to treat fungal infections including nail infections - NHS

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Fluconazole - Brand name: Diflucan

On this page

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

1. About fluconazole

Fluconazole is an antifungal medicine. It's used to treat infections caused by different kinds of fungus.

The most common cause of fungal infections is a yeast called candida.

Fluconazole is used to treat many infections caused by candida including:

Fluconazole is also used to treat a brain infection called cryptococcal meningitis. This is caused by a fungus called cryptococcus.

Fluconazole can also be used to prevent a fungal infection developing. It is only prescribed if you are likely to get this sort of infection. This includes people who:

Fluconazole is available as capsules or a liquid that you swallow.

It also comes as an injection, but this is usually given in hospital.

Fluconazole is usually prescribed for you by a doctor. You can also buy it from a pharmacy for vaginal thrush or balanitis.

2. Key facts

  • You'll usually take fluconazole once a day.
  • Your dose and how long you take it for depends on the kind of infection you have.
  • You can take fluconazole with or without food.
  • The most common side effects of fluconazole are feeling sick (nausea) and diarrhoea.
  • For thrush, you can buy fluconazole capsules (brand names include Canesten Thrush Oral Capsules) or fluconazole capsules with clotrimazole cream (brand names include Canesten Thrush Duo).

3. Who can and cannot take fluconazole

Most adults and children can take fluconazole. It can also be prescribed for babies.

Fluconazole is not suitable for everyone. Tell a pharmacist or your doctor before taking it if you have:

  • had an allergic reaction to fluconazole or any other medicines in the past
  • heart disease, including heart rhythm problems (arrhythmia)
  • kidney or liver problems
  • a rare, inherited blood disorder called acute porphyria
  • had a blood test that showed you have abnormal levels of potassium, calcium or magnesium

4. How and when to take fluconazone

Follow the advice from your doctor. If you buy fluconazole in a pharmacy, follow the instructions that come with the medicine.

It's important to complete the course of medicine even if you feel better.

You can take fluconazole capsules and liquid with or without food.

Fluconazole capsules are either 50mg, 150mg or 200mg. Swallow the capsules whole with a drink of water. It is best to take your capsules at the same time each day.

The liquid usually comes in 2 different strengths:

  • 50mg fluconazole in a 5ml spoonful (50mg/5ml)
  • 200mg fluconazole in a 5ml spoonful (200mg/5ml)

Use the plastic spoon that comes with your medicine to measure your dose. Do not use a kitchen teaspoon, as this will not give you the right amount.

Dosage for capsules or liquid

These are the usual doses for adults:

  • oral (mouth) thrush – 50mg a day, taken for 7 to 14 days
  • vaginal thrush or balanitis – 150mg, taken as a single dose
  • vaginal thrush that keeps coming back – 150mg, taken once every 72 hours for the first 3 doses, then take 150mg once a week for 6 months
  • candida infections (in your blood or elsewhere in your body) – 200mg to 800mg a day for several weeks
  • cryptococcal meningitis – 200mg to 800mg a day for several weeks
  • to stop cryptococcal meningitis coming back – 200mg a day, taken long term
  • to prevent fungal infections if you have a weakened immune system (a low white blood cell count) – 50mg to 400mg a day, until your white blood cell count improves

For children, your doctor will work out the right dose depending on the infection and your child's age and weight.

If you take your fluconazole once every 72 hours, or once a week, it may help to use a calendar and mark the days when you need to take it.

What if I forget to take a dose?

If you forget a dose, take it as soon as you remember, unless it's nearly time for your next dose. In this case, just skip the missed dose and take your next one as normal.

Do not take a double dose to make up for a missed dose.

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

What if I take too much?

Accidentally taking 1 or 2 extra doses is unlikely to harm you.

Urgent advice: Speak to your doctor or pharmacist now if:

  • your child takes too much fluconazole
  • you take too much fluconazole and have side effects or feel unwell

5. Side effects

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

Common side effects

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

Talk to your doctor or a pharmacist if these side effects bother you or do not go away:

  • headache
  • stomach pain
  • diarrhoea
  • feeling or being sick (nausea or vomiting)
  • rash

Serious side effects

Serious side effects are rare and happen in less than 1 in 100 people.

Call a doctor immediately if:

  • you get yellow skin, or the whites of your eyes turn yellow, or if you have pale poo and dark pee – these can be signs of liver problems
  • you bruise more easily or get infections more easily – these can be signs of a blood disorder
  • you have a faster or irregular heartbeat

Serious allergic reaction

It happens rarely but it is possible to have a serious allergic reaction (anaphylaxis) to fluconazole.

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

Information:

You can report any suspected side effect to the .

6. How to cope with side effects

What to do about:

  • headache – rest and drink plenty of fluids. Do not drink too much alcohol. Ask a pharmacist to recommend a painkiller if you need one. Talk to your doctor if the headaches last longer than a week or are severe.
  • stomach pain – 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 tummy may also help. If you are in a lot of pain, speak to a doctor or pharmacist.
  • diarrhoea – drink lots of fluids, such as water or squash, to avoid dehydration. Speak to a pharmacist if you have signs of dehydration, such as 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.
  • feeling or being sick (nausea or vomiting) – stick to simple meals and do not eat rich or spicy food. If you are being sick, try small, frequent sips of water to avoid dehydration. It might help to take your fluconazole after a meal or snack.
  • rash – it may help to take an antihistamine, which you can buy from a pharmacy. Check with the pharmacist to see what type is right for you. If the rash gets worse, or does not get better after a week, speak to your doctor.

7. Pregnancy and breastfeeding

Fluconazole and pregnancy

Fluconazole is usually not recommended in pregnancy. Some studies have found that taking fluconazole in pregnancy can harm your baby.

If you have thrush, ask your GP or midwife for advice about treatments. Your doctor will probably prescribe clotrimazole or a similar antifungal medicine. This may be as a cream or as a soft tablet (a pessary) that you put into your vagina.

If the thrush does not go away, they may prescribe a single dose (150mg) of fluconazole. They will discuss the risks and benefits to you and your baby.

If the fungal infection is more serious, your doctor may recommend a higher dose of fluconazole, if it is the best treatment option. Talk to them about the risks and benefits to you and your baby.

Read more on the Best Use of Medicines in Pregnancy (BUMPs) website about taking or .

Fluconazole and breastfeeding

If your doctor or health visitor says your baby is healthy, you can use fluconazole when you're breastfeeding. Breastfeeding will benefit you and your baby.

If you notice that your baby is not feeding as well as usual, or seems unusually sleepy, or if you have any other concerns about your baby, then talk to your 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 and fluconazole interfere with each other.

Tell your doctor if you are taking any of these medicines before you start taking fluconazole:

  • pimozide or quetiapine – used to treat some kinds of mental illness
  • reboxetine – used for treating depression
  • erythromycin – an antibiotic
  • ergotamine – used for migraine or headaches
  • amiodarone – used for heart problems
  • warfarin – an anticoagulant
  • carbamazepine – for epilepsy and nerve pain
  • losartan – for high blood pressure and heart failure
  • statins – for high cholesterol

These are not all the medicines that interfere with fluconazole. For a full list, see the leaflet inside your medicines packet.

Mixing fluconazole with herbal remedies and supplements

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

Important

Tell a pharmacist or doctor if you are taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions

How does fluconazole work?

Fluconazole works by killing the fungus (or yeast) that is causing the infection.

The medicine kills fungus by making holes in its cell membrane, so that the contents leak out. This treats the infection and allows your symptoms to get better.

If you are taking fluconazole to prevent an infection, the medicine kills any fungus as it starts to appear.

How long does it take to work?

Fluconazole is used for many different fungal infections.

If you have vaginal thrush, balanitis or oral thrush, your symptoms should be better within 7 days of taking fluconazole.

If you have a serious fungal infection, ask your doctor how long it will take for fluconazole to start to work. It may be 1 to 2 weeks before it reaches its full effect.

What if it does not work?

Talk to your doctor if your symptoms do not improve after 7 days of taking fluconazole for vaginal thrush, balanitis or oral thrush.

Your doctor may ask you to take fluconazole for longer, or they may prescribe a different antifungal treatment.

If your symptoms get worse at any time, speak to your doctor.

How long will I take it for?

It depends on why you're taking fluconazole and whether your infection is getting better.

It could be a single dose, or treatment for several weeks, months or even years.

If your doctor prescribes a course of fluconazole, they will advise you how long to take it for. Keep taking your medicine until the course is finished, even if you start to feel better. This will help to stop the infection coming back.

Speak to your doctor if you want to stop taking it for any reason.

Is fluconazole safe to take for a long time?

You usually take fluconazole for a short time to clear an infection.

If you have a serious infection, you may need to take fluconazole long term. It is safe to take for a long time if your doctor has advised you to.

If you take fluconazole long term, your doctor may ask you to have regular blood tests.

Are there other medicines for fungal infections?

There are many different antifungal medicines. Some are available to buy from a pharmacy, others are available on prescription.

They can come as creams, gels, sprays, pessaries (soft tablets you put into your vagina), tablets, capsules, liquid, or injections.

Your doctor or a pharmacist will be able to recommend the best treatment for you, based on your condition.

Antifungal medicines include:

  • clotrimazole
  • econazole
  • fenticonazole
  • itraconazole
  • ketoconazole
  • miconazole
  • griseofulvin
  • terbinafine
Will it affect my contraception?

Fluconazole is not likely to affect your contraception, including the combined pill or emergency contraception.

If taking fluconazole makes you vomit or have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.

Find out what to do if you're taking the pill and you're being sick or have diarrhoea.

There have been some reports of "breakthrough bleeding", known as spotting, when people take fluconazole and the combined pill together. It is not known whether this is to do with the fluconazole. If you get any breakthrough bleeding while using oral contraception, speak to your doctor.

Some studies have shown that there is a small chance that fluconazole could increase the levels of hormones in your body when using the combined pill. You can continue taking fluconazole with your oral contraception, but if you get any side effects, such as feeling sick or tender breasts, speak to your doctor.

Will it affect my fertility?

There is no clear evidence to suggest that fluconazole will reduce fertility in either men or women.

Can I drink alcohol with it?

You can drink alcohol while taking fluconazole.

Is there any food or drink I need to avoid?

No, you can eat or drink normally while taking fluconazole.

Can I drive or ride a bike?

Yes, you can drink or ride a bike while taking fluconazole.

In rare cases, taking fluconazole can make you feel dizzy or lightheaded. If you're affected, do not drive or cycle until this feeling goes away. 

Useful resources

Page last reviewed: 23 March 2020
Next review due: 23 March 2023