How does nitrofurantoin work?
Nitrofurantoin enters your urine and targets bacteria in the bladder and urinary tract, stopping them from growing and spreading. Because it works directly in the urine, it isn’t effective for infections elsewhere in the body.
What is nitrofurantoin used to treat?
Nitrofurantoin is used to:
- Treat urinary tract infections (UTIs), such as cystitis
- Prevent recurrent UTIs in people prone to frequent infections
Who can take nitrofurantoin?
Most adults and children over 3 months old can take nitrofurantoin. It is often prescribed to women, who are more prone to UTIs, but men can take it too.
Who might not be able to take nitrofurantoin?
Nitrofurantoin may not be suitable if you:
- Are allergic to nitrofurantoin or similar antibiotics
- Have severe kidney disease (as the medicine needs to reach your urine to work)
- Have a condition called G6PD deficiency (a rare enzyme disorder)
- Are in the final stages of pregnancy (as it may affect the baby’s red blood cells)
Can I take nitrofurantoin if I’m pregnant or breastfeeding?
Nitrofurantoin is usually safe to take during pregnancy, except in the last few weeks before birth. If you’re pregnant or breastfeeding, speak to your doctor first.
What if I miss a dose?
If you forget to take a dose, take it as soon as you remember. If it’s nearly time for your next dose, skip the missed one—don’t take two doses at once.
How effective is nitrofurantoin?
Nitrofurantoin is highly effective when taken correctly. It starts working within a few hours, and most people feel better after a few days. However, it’s important to finish the full course to fully clear the infection.
What should I do if I take too much?
Taking too much nitrofurantoin may cause nausea, vomiting, or dizziness. If you accidentally take more than your prescribed dose, contact a doctor or pharmacist for advice.
What dose of nitrofurantoin is usually taken?
The usual dose depends on the condition being treated:
- For a short-term UTI treatment: 50mg to 100mg four times a day for 3 to 7 days
- For long-term prevention of UTIs: 50mg to 100mg once a day, often taken at night
Always take nitrofurantoin exactly as prescribed by your doctor.
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What are the side effects of nitrofurantoin?
Not everyone gets side effects, but common ones include:
- Feeling sick (nausea) or being sick (vomiting)
- Loss of appetite
- Headaches
- Diarrhoea
- Dark yellow or brown urine (this is harmless)
Serious side effects are rare but can include lung or liver problems. Seek medical help if you experience shortness of breath, a persistent cough, jaundice (yellowing of the skin or eyes), or unusual tiredness.
How should I take nitrofurantoin?
Nitrofurantoin is usually taken as capsules or tablets. To reduce the risk of stomach upset, take it with food or milk.
When should nitrofurantoin be taken?
Nitrofurantoin is typically taken twice or four times a day, depending on the prescribed dose. Try to take each dose at the same times every day to help you remember.
What are the brand names for nitrofurantoin?
Nitrofurantoin is available under brand names such as:
- Macrobid
- Macrodantin
- Furadantin
Final thoughts
Nitrofurantoin is a widely used and effective antibiotic for treating and preventing UTIs. To get the best results, take it exactly as prescribed and complete the full course. If you have any concerns about side effects or how it’s working, speak to a healthcare professional.
