What it is used for
- Treatment of some urinary tract infections (cystitis)
- Prevention of repeated urinary tract infections in some people
How it works
Nitrofurantoin is an antibiotic that concentrates in the urine, where it damages bacteria so they cannot survive. Because it mainly acts in the bladder and urine, it is used for urinary infections rather than infections elsewhere in the body.
How it is taken
Comes as capsules, tablets and a liquid (oral suspension). Take it exactly as your doctor or pharmacist directs and follow the label. Taking it with food helps absorption and reduces stomach upset. Complete the full course as advised.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Nausea
- Loss of appetite
- Diarrhoea
- Headache
- Dark yellow or brown urine (harmless)
Serious effects — get help
- New cough, breathlessness or chest pain (rare lung reaction)
- Numbness, tingling or weakness in the hands or feet (possible nerve effect)
- Yellowing of the skin or eyes (possible liver problem)
- Severe allergic reaction with swelling or breathing difficulty
- Unusual tiredness or pale skin (possible blood problem)
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Antacids containing magnesium (may reduce absorption)
- Some gout medicines such as probenecid
- Medicines that make the urine more alkaline
- Certain stomach-acid medicines
Who should take care
- Not suitable for people with significantly reduced kidney function, as it may not work and side effects rise
- Usually avoided near the end of pregnancy and in newborn babies
- Tell your clinician if you have a known G6PD deficiency
- Tell your clinician about any lung, liver or nerve problems
- Take with food and complete the course