Nitrofurantoin
NHS information about the medicine nitrofurantoin, including what it's used for, who can take it, how to take it and side effects.
What nitrofurantoin is for
Nitrofurantoin is used to treat urinary tract infections (UTIs) such as cystitis.
It may also be prescribed to help prevent UTIs.
How to take nitrofurantoin
Nitrofurantoin usually comes as capsules, tablets and a liquid you swallow.
How much you need to take and for how long depends on why you're taking it. Most people need to take it for 3 to 7 days.
Nitrofurantoin can also be prescribed for long-term use if you get UTIs that keep coming back, or as a single-use medicine. You may only need to use it once to prevent a UTI before surgery, for example, or before coming into contact with a known trigger.
When taking nitrofurantoin:
- the dose will depend on the type of capsule or tablet you're taking – some are slow release (prolonged release) which means you do not have to take them as often
- swallow the tablets or capsules whole – do not break or chew them
- try to space your doses evenly throughout the day if you're taking more than 1 dose a day
- use the syringe or spoon that comes with the liquid medicine to measure the right dose
- you can take it with food or a glass of milk – this makes it easier for the medicine to work
Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or have any problems taking it.
Side effects of nitrofurantoin
Like all medicines, nitrofurantoin can cause side effects, although not everyone gets them.
Side effects
Side effects of nitrofurantoin can include:
- nausea (feeling sick)
- diarrhoea
- loss of appetite
- headaches
- turning your pee a dark yellow or brownish colour
Side effects usually go away when you stop taking the medicine.
Nitrofurantoin will not usually affect your ability to drive, ride a bike or use machinery.
More about side effects
These are not all the side effects of nitrofurantoin.
For a full list, see the leaflet that comes with your medicine or search for your medicine leaflet on the electronic medicines compendium website.
You can report any side effects you get on the Yellow Card website
Who can and cannot take nitrofurantoin
Most adults and children over 3 months old can take nitrofurantoin.
But nitrofurantoin is not suitable for everyone. For example, it may not be suitable if:
- you've previously had an allergic reaction or other serious side effect from nitrofurantoin
- you have a lung condition
- you have severe kidney problems
- you have diabetes
- you have anaemia or vitamin B deficiency
- you have a condition that affects your blood called porphyria
Before taking nitrofurantoin, tell your doctor if you have any medical conditions.
Breastfeeding and nitrofurantoin
You can usually take nitrofurantoin while breastfeeding, but check with a pharmacist or doctor first.
It's rare for breastfed babies to get any side effects from medicine you're taking, but speak to a healthcare professional if you have any concerns about your baby or call NHS 111.
Pregnancy and nitrofurantoin
You can usually take nitrofurantoin before week 28 of pregnancy.
A doctor may not recommend nitrofurantoin after week 28 of pregnancy because it can affect your baby's red blood cells, but they will talk to you about the benefits and risks.
Nitrofurantoin is the best medicine to treat a UTI and it's important to treat them if you're pregnant.
Taking nitrofurantoin with other medicines, food and drink
There are some medicines, remedies and supplements that may not mix well with nitrofurantoin.
This includes some types of:
- medicines to treat indigestion, such as antacids
- medicines to treat certain infections, such as quinolones
- medicines, such as acetazolamide, to treat glaucoma
- medicines to treat cystitis that you buy from a pharmacy
Before taking nitrofurantoin, tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements.
Food, drink and alcohol with nitrofurantoin
You can eat and drink as normal while taking nitrofurantoin. It's best to take nitrofurantoin with food.
Find out more about your medicine
To find out more about your medicine, you can:
- check the leaflet that comes with it
- search for your medicine leaflet on the electronic medicines compendium website
- speak to a pharmacist or a doctor for advice
