Nitrofurantoin

Sounds like 'night-roh-few-ran-to-in'

Key points about nitrofurantoin

  • Nitrofurantoin is an antibiotic used to treat and prevent urinary tract infections.
  • Nitrofurantoin is also called Nifuran® or Macrobid®.
  • Find out how to take it safely and the possible side effects.
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Nitrofurantoin is an antibiotic used to treat and prevent infections of the urinary tract (UTIs), such as bladder infections. It works by killing or stopping the growth of the bugs that cause the infection. For people who get urinary tract infections often, nitrofurantoin can be used to prevent infections. Read more about urinary tract infections in men, women, pregnancy and children.

In Aotearoa New Zealand, nitrofurantoin is available as:

  • Nifuran® tablets (50 mg and 100 mg)
  • Macrobid® modified release capsules (100 mg).

From October 2022, some pharmacists will be able to sell Macrobid capsules for the treatment of UTIs. This is available without a prescription to women 16 to 65 years of age, who are not pregnant and don't have any other complicating factors. Only pharmacists who have completed additional training can supply Macrobid capsules. They will need to ask you questions to make sure it's the best option for you and will need to record your name and address.

Always take nitrofurantoin exactly as your healthcare provider has told you. The pharmacy label on your medicine will tell you how much to take, how often to take it, and any special instructions.

Nifuran tablets

  • Take Nifuran tablets with food or milk.
  • Space your doses evenly throughout the day. For example, for Nifuran 50 mg tablets with 4 times a day dosing, take your tablets first thing in the morning (before breakfast), at around midday (before lunch), late in the afternoon (before tea) and at bedtime.
  • If you're taking the tablets once a day, take your dose at bedtime.

Macrobid capsules

  • Take your capsules with or just after food or a meal.
  • Take your dose every 12 hours, in the morning and the evening, eg, take it at 8am and 8pm.
  • Swallow the capsule whole with a glass of water, don't crush it or chew it.

Missed dose: If you forget to take your dose, take it as soon as you remember. But if it's nearly time for your next dose, just take the next dose at the usual time. Don't take double the dose or take 2 doses close together.

Finish the course: If you're taking nitrofurantoin for the treatment of an infection, it's best to take the antibiotic for the exact number of days your doctor has told you to. Don't stop taking it, even if you feel your infection has cleared up. Talk to your healthcare provider first.

Here are some things to know when you're taking nitrofurantoin. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Other medicines: Nitrofurantoin interacts with some medicines, eg, antacids like Quick-Eze, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting nitrofurantoin and before starting any new products.
  • Let your doctor know if you have any problems with your kidneys.

Like all medicines nitrofurantoin can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Feeling sick (nausea)
  • Stomach upset
  • Bloating and gas in the stomach
  • This is quite common when you first start taking nitrofurantoin and usually goes away with time.
  • Take nitrofurantoin with food.
  • Tell your doctor if this continues.
  • Dark yellow or brown urine
  • This is common when you are taking nitrofurantoin.
  • It is not harmful.
  • Talk to your doctor if you are worried.
  • Cough, chest pain, shortness of breath
  • Tell your doctor.
  • Signs of problems with your liver such as yellowing of the eyes or skin, or tummy pain 
  • Tell your doctor.
  • Signs of problems with your lungs such as cough, chest pain, shortness of breath and trouble breathing, 
    joint or muscle pain, fever (high temperature) and chills.  
  • Rarely, nitrofurantoin can cause lung problems.
  • This may occur within the first month of treatment or after long-term use of nitrofurantoin (generally for 6 months or longer).
  • Tell your doctor immediately or ring Healthline 0800 611 116.
  • Signs of an allergic reaction such as a skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing such as chest tightness, or wheezing
  • This usually occurs within the first week of starting treatment.
  • Tell your doctor immediately or ring Healthline 0800 611 116.

Read more about medicines and side effects and reporting a reaction you think might be a side effect.

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

Last reviewed: