In short

  • The antibacterial Nitrofurantoin is used primarily to treat urinary tract infections.
  • It gets rid of bacteria in the body but at the same time can cause a few side effects.
  • A potent medication like this is never going to be without at least some side effects, and you should know what those are before you agree to start using it.

The antibacterial Nitrofurantoin is used primarily to treat urinary tract infections. It gets rid of bacteria in the body but at the same time can cause a few side effects. A potent medication like this is never going to be without at least some side effects, and you should know what those are before you agree to start using it. It should be noted that not everyone will share the same side effects, and while one person’s may be mild, another person’s can be quite severe. You simply won’t know what kind of side effects you will end up with until you start to take the drug.

That being said, we do have a good idea as to what side effects should be expected, just from research and tests already performed. If, for some reason, you start to experience any side effects beyond those listed here while taking the drug, you need to let your doctor know right away.

Common Side Effects

The majority of the side effects experienced with this drug will be mild and will go away over time. Most people will only experience some slight diarrhoea or gassiness when they take it. If you have a problem with either of these, you can take some over-the-counter medications to deal with them.

There are other fairly common side effects that you need to be aware of that are more dangerous. These are ones that require you to contact your doctor should you start to experience them.

These include among others:

  • facial flushing
  • cough
  • fever
  • itching
  • skin rash
  • difficulty breathing
  • muscle pain

These are considered severe symptoms, and even though they are fairly common, you need to let your doctor know if you start to experience them.

Rare Side Effects

Other more serious side effects are not as common, but since they can still occur, you should be aware of the possibility.

The milder rare side effects include:

  • dizziness
  • headache
  • sore throat
  • loss of balance
  • red dots on the skin
  • bloody stool or urine
  • weakness (particularly in the arms or legs)
  • unusual tiredness or bruising

These are potentially serious side effects. Since they are rare, they may indicate a deeper underlying problem, and it’s a good idea to report them to your doctor.

The more severe rare side effects include:

  • cracks on the skin
  • darkened urine
  • changes in vision
  • pale skin
  • pale stool
  • loss of appetite
  • a feeling of heat loss
  • moodiness and mental changes

If you start to experience any of the side effects, you need to get medical help right away. If your doctor is not available, then contact a hospital or a medical professional for assistance. These side effects may end up being nothing, but you should not take that chance.

The rarer side effects have the potential to lead to more serious health problems because there are harder to predict and thus more difficult to understand fully.

Other side effects may occur as well, including ones not listed here or on any list of side effects for the drug Nitrofurantoin. Suppose you experience any side effects that may be attributed to taking this drug, and they are not covered in any of the comprehensive side effects lists. In that case, you should treat the problem as a rare and potentially dangerous side effect that requires immediate treatment.

Sources

References

2 sources were selected to match the subject of this article. Link destinations were checked twice when added. This does not mean every statement has been individually source-mapped or clinically approved.

  1. About nitrofurantoin

    NHS · HTML · NHS medicine guidance · Link destination checked 5 September 2026

  2. Urinary tract infections (UTIs)

    NHS · HTML · NHS condition guidance · Link destination checked 5 September 2026

Reference links open the cited source pages. If you spot something out of date, tell our content team.

Who wrote this

Written and reviewed by our team

Authored by

Hywel McGlinchy - Pharmacist and Medical Writer

Pharmacist / Content Writer

Hywel has been a registered pharmacist since 2017; he started with Simple Online Pharmacy in 2020. Hywel was responsible for helping review and author accurate site content. He worked with our GPs to make sure all aspects of the medications mentioned are covered.

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Medically reviewed by

Karim Nassar, Co-Founder, Pharmacist & Author

Karim Nassar

Co-Founder, Pharmacist & Author

Karim is a registered pharmacist with the General Pharmaceutical Council (GPhC) and was a founding member of Simple Online Healthcare in 2015. With a Master of Pharmacy degree from Strathclyde University, Karim brings a strong foundation in pharmaceutical care and a passion for leveraging digital solutions to improve patient access to healthcare.

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Sources cited

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