Nitrofurantoin

What is Nitrofurantoin?

A UTI is a common infection that can affect your bladder, kidneys and urethra. It can be caused by things like:

• Not fully emptying your bladder when you pee
• Kidney stones
• Wiping the wrong way (‘back to front’ rather than ‘front to back’)
• Not peeing after sex

Although they can clear up on their own, they might need treatment with antibiotics. Nitrofurantoin is an antibiotic that can be taken as a capsule or tablet, and targets the bacteria causing your UTI at the site of the infection. ^[1]

You might start to feel better after only a few days of taking Nitrofurantoin, but as with all antibiotics, it’s important to finish the entire course of pills. Unlike other antibiotics, Nitrofurantoin is used solely to treat and prevent lower urinary tract infections like cystitis.

How does Nitrofurantoin work?

Antibiotics work by killing or stopping the spread of bacteria. Unlike other antibiotics that are prescribed to treat a wide range of infections, like penicillin, Nitrofurantoin is used specifically for urinary tract infections (UTIs). When these infections affect the bladder, it’s called cystitis. Cystitis can also be treated with Nitrofurantoin.

To reach the site of the infection, a Nitrofurantoin filters out from your blood and into your urine. Here, it can target the bacteria in your urinary tract and destroy them. Although antibiotics can start to work within a few days, you’ll need to take the entire course to make sure your infection has cleared. ^[2]

What doses of Nitrofurantoin are there?

Nitrofurantoin is available in 50mg or 100mg strength tablets and capsules. The standard dose to clear a urinary tract infection for men is four 50mg tablets or capsules each day, for seven days; or for women: four 50mg pills a day for three days. The strength you’re prescribed can depend on how severe your UTI is and how often you get them.

You should try to space the doses out over the day to avoid taking too little or too much Nitrofurantoin. If you’re taking four 50mg tablets or capsules, take one in the morning, one around midday, your third in the late afternoon and your final dose before you go to bed.

How to take Nitrofurantoin

Nitrofurantoin capsules and tablets should be swallowed whole with a glass of water.

It’s recommended you take Nitrofurantoin with food or a glass of milk to avoid an upset stomach. It also helps the medication absorb into your system more easily.

How long does Nitrofurantoin take to work?

You might start feeling better after only a few days of using Nitrofurantoin. To make sure the infection has cleared completely, you should take the entire course of medication as it’s been prescribed.

As you can’t always see visible evidence of medications like Nitrofurantoin working, it can be easy to think your UTI has been treated as soon as you stop experiencing uncomfortable symptoms like pain in your tummy or a frequent urge to pee. Stopping Nitrofurantoin before the full course is finished can lead to future urinary tract infections, and can even help the bacteria that causes them become resistant to antibiotics. ^[1]

If you’ve still got symptoms after completing your course of Nitrofurantoin, let your doctor know. If cystitis is left untreated it could cause complications like kidney infections, scarring, or blood in your urine.

What should I do if I make a mistake when using Nitrofurantoin?

Doses of Nitrofurantoin should be spaced out so the medication can work effectively. If you forget to swallow a tablet or capsule at your usual time, you can take it as soon as you remember provided it’s not too soon before your next dose is due. In that case, just skip the one you missed and carry on your usual dosage routine.

If for any reason you take too much Nitrofurantoin, go to your nearest hospital’s emergency department immediately.