How does nitrofurantoin work?
Nitrofurantoin works in a different way from other antibiotics.
When you take it by mouth, most of it gets filtered out of your blood and into your pee. This concentrates the medicine where the bacteria are that are causing the urinary tract infection.
Nitrofurantoin kills the bacteria by entering their cells and damaging their genetic material.
When will I feel better?
You should feel better within a few days.
It's important that you keep taking nitrofurantoin until your course is finished. Do this even if you feel better. It will help stop the infection coming back.
If you're taking nitrofurantoin to stop urinary tract infections coming back, you may not have any symptoms or feel unwell, but you will still need to carry on taking it for several months.
What if I do not get better?
Tell your doctor if you do not start feeling better after taking nitrofurantoin for 3 days, or if you start to feel worse at any time.
Will it give me thrush?
Some people get a fungal infection called thrush after taking a course of antibiotics like nitrofurantoin. It happens because antibiotics kill the normal harmless bacteria that help to protect you against thrush.
Ask your pharmacist or doctor for advice if this happens to you.
Will it affect my contraception?
Nitrofurantoin does not stop any type of contraception from working, including the combined pill and emergency contraception.
However, if nitrofurantoin makes you sick (vomit) or you 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 more about what to do if you're on the pill and you're being sick or have diarrhoea.
Can I drive or ride a bike?
Nitrofurantoin can make you feel dizzy or sleepy. If this happens, do not drive or cycle until you feel better.
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.
Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking nitrofurantoin. GOV.UK has more information on the law on drugs and driving.
Can I drink alcohol while taking nitrofurantoin?
Yes, you can drink alcohol with nitrofurantoin.
Is there any food or drink I need to avoid?
You can eat and drink normally while taking nitrofurantoin.
Can drinking cranberry juice help urinary tract infections?
It's unlikely that drinking cranberry juice or taking cranberry supplements helps treat or prevent urinary tract infections.
Can lifestyle changes help urinary tract infections?
It's possible that a straightforward urinary tract infection will clear up on its own without any treatment. But it's usually best to treat a urinary tract infection with an antibiotic, or it could spread to the kidneys and lead to more serious problems.
Once treated, there are many steps you can take to stop urinary tract infections coming back:
- avoid perfumed bubble bath, soap or talcum powder around your genitals – use plain, unperfumed varieties, and have a shower rather than a bath
- go to the toilet as soon as you need to pee, and always empty your bladder fully
- stay well hydrated – aim to drink 6 to 8 glasses of fluid a day (water, lower-fat milk and sugar-free drinks, including tea and coffee, all count)
- wipe your bottom from front to back when you go to the toilet
- empty your bladder as soon as possible after having sex
- do not use a contraceptive diaphragm or condoms with spermicidal lubricant on them – use another type of contraception instead
- wear underwear made from cotton, rather than synthetic material like nylon
- avoid tight jeans and trousers