Nitrofurantoin 50mg Capsules

Patient Leaflet Updated 05-Feb-2024 | ADVANZ Pharma

Nitrofurantoin 50mg and 100mg Capsules

Package leaflet: Information for the user

Nitrofurantoin 50mg and 100mg Capsules, Hard


Read all of this leaflet carefully before you start taking this medicine because it contains important information for you.

Keep this leaflet. You may need to read it again.

If you have any further questions, ask your doctor, pharmacist or nurse.

This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. See section 4.

The name of your medicine is Nitrofurantoin 50mg or 100mg capsules, Hard. It will be referred to as Nitrofurantoin capsules for ease hereafter.

What is in this leaflet:

1. What Nitrofurantoin Capsules are and what they are used for
2. What you need to know before you take Nitrofurantoin Capsules
3. How to take Nitrofurantoin Capsules
4. Possible side effects
5. How to store Nitrofurantoin Capsules
6. Contents of the pack and other information

1. What Nitrofurantoin capsules are and what they are used for

Nitrofurantoin (the active substance in Nitrofurantoin Capsules) is an antibiotic.

It is used to prevent and treat infections of the bladder, kidney and other parts of the urinary tract.

You must talk to a doctor if you do not feel better or if you feel worse.

2. what you need to know before you take Nitrofurantoin capsules
Do not take Nitrofurantoin Capsules:
  • if you are allergic to nitrofurantoin, other nitrofurans or to any of the other ingredients of this medicine (listed in Section 6)
  • if you have a disease of the kidneys which is severely affecting the way they work (ask your doctor if you are not sure)
  • if you are in the final stages of pregnancy (labour or delivery) as there is a risk that it might affect the baby
  • if you suffer from a blood disorder called porphyria
  • if you are deficient in an enzyme called G6PD (glucose-6-phosphate dehydrogenase)
  • if your child under three months of age
  • if you are breast feeding a baby with suspected or known deficiency in an enzyme called G6PD (glucose-6-phosphate dehydrogenase).

Tell your doctor if you are not sure about any of the above.

Warnings and precautions

Talk to your doctor, pharmacist or nurse before taking Nitrofurantoin Capsules:

  • if you have diabetes
  • if you are suffering from any illness causing severe weakness
  • if you have anaemia (a decrease in red blood cells causing pale skin, weakness and breathlessness); or a lack of vitamin B or abnormal levels of salts in your blood (your doctor will be able to advise you)
  • if you have a history of allergic reactions.
  • if you have any problems with your kidneys
  • if you have disease of the lungs
    This medicine can also cause lung disease in patients with no previous medical history affecting their lungs. Lung disease can occur in patients on short-term or long-term treatment. Talk to your doctor if you experience trouble breathing, shortness of breath, a lingering cough, coughing up blood or mucus, or pain or discomfort when breathing. These may be symptoms of side effects affecting the lungs.

The above conditions may increase the chance of developing a side effect which results in damage to the nerves, causes altered sense of feeling, pins and needles.

  • if you lack an enzyme (body chemical) called glucose-6-phosphate dehydrogenase, which causes your red blood cells to be more easily damaged (this is more common in black people and people of Mediterranean, Middle Eastern or Asian origin. Your doctor will know)
  • if you have any disease of the lungs, liver or nervous system. If you need to take Nitrofurantoin Capsules for a number of months, your doctor may want to regularly check how your lungs and liver are working.
  • as this medicine may interfere with urine tests for glucose, causing the test to give a “false positive” result. That is, the test may say that glucose is present in the urine even if it is not.
    This medicine may also cause your urine to turn yellow or brown.
  • If you experience fatigue, yellowing of the skin or eyes, itching, skin rashes, joint pain, abdominal discomfort, nausea, vomiting, loss of appetite, dark urine, and pale or gray-colored stools. It may be symptoms of liver disorder.

Other medicines and Nitrofurantoin Capsules

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.

If they are taken with Nitrofurantoin Capsules their effect or the effect of Nitrofurantoin Capsules may be changed.

In particular, tell your doctor or pharmacist if you are taking any of the following medicines:

  • Antacids for indigestion (e.g. magnesium trisilicate)
  • Medicines for gout (e.g. probenecid or sulfinpyrazone)
  • Medicines which slow the passage of food through the stomach (e.g. atropine, hyoscine)
  • Medicines for raised pressure in the eye (glaucoma), such as carbonic anhydrase inhibitors (e.g. acetazolamide)
  • Medicines which make the urine less acidic (e.g. potassium citrate mixture)
  • Medicines for infections, known as quinolones
  • Typhoid vaccine, which is given for the prevention of typhoid.

If you are in doubt about any of these medicines, ask your doctor or pharmacist.

Nitrofurantoin Capsules may interfere with the results of some tests for glucose in the urine.

Nitrofurantoin Capsules with food and drink

Nitrofurantoin Capsules should always be taken with food or milk. Taking this medicine with food or milk makes it work more effectively. This will help to avoid stomach upset and also to help the absorption.

Pregnancy and breast-feeding

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

As far as it is known Nitrofurantoin Capsules may be used in pregnancy.

However, it should not be used during labour or delivery because there is a possibility that use at this stage may affect the baby. If you want to breast feed, please consult your doctor first.

Driving and using machines

Nitrofurantoin Capsules may cause dizziness and drowsiness. You should not drive or operate machinery if you are affected this way until such symptoms go away.

Nitrofurantoin Capsules contains lactose

If you have been told by your doctor that you are intolerant to some sugars, contact your doctor before taking this medicine.

Information on sodium content

This medicine contains less than 1 mmol sodium (23 mg) per dosage, that is to say essentially ‘sodium-free’.

3. How to take Nitrofurantoin capsules

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.

The recommended dose is:


The normal dosage depends on the type of infection you have, and instructions should be written on the label provided by the pharmacist. Consult your pharmacist or doctor if these instructions are not clear. The usual doses are:

  • For treatment of infections: Either one 50mg capsule or one 100mg capsule four times a day for seven days
  • For prevention of further infections: Either one 50mg capsule or one 100mg capsule at bedtime
  • For prevention of infections during surgery: One 50mg capsule four times a day on the day of the operation and three days thereafter.

Use in children and infants over three months of age:

The dose depends on the weight of the child and will be provided by your doctor. Follow your doctor’s instructions exactly.

Children below 3 months of age should not take Nitrofurantoin Capsules.

Medical Checks:

Your doctor will watch carefully for any effects on the liver, lungs, blood or nervous system. Nitrofurantoin Capsules may interfere with the results of some tests for glucose in the urine.

Method of administration

Nitrofurantoin Capsules should always be taken with food or milk. Taking this medicine with food or milk makes it work more effectively.

If you take more Nitrofurantoin Capsules than you should:

Consult your doctor or pharmacist immediately or go to the emergency department of the nearest hospital. Always take any leftover capsules with you, as well as the container and label, so that the medical staff knows what you have taken.

If you forget to take Nitrofurantoin Capsules:

Do not worry. If you remember later on that day, take that day’s dose as usual. If you miss a whole day’s dose take the normal dose on the next day. Do not take a double dose to make up for a forgotten capsule. If you are not sure ask your doctor or pharmacist.

If you stop taking Nitrofurantoin Capsules:

Your doctor will tell you how long to take the treatment. Do not stop earlier than you are told, even if you feel better.

If you have any further questions on the use of this medicine, ask your doctor, pharmacist or nurse.


Like all medicines, this medicine can cause side effects, although not everybody gets them. Most of them are mild and disappear when you stop taking Nitrofurantoin Capsules.

All medicines can cause allergic reactions although serious allergic reactions are rare. If you notice any sudden wheeziness, difficulty in breathing, swelling of the eyelids, face or lips, rash or itching (especially affecting your whole body) STOP TAKING your medicine and go to a doctor immediately.

If you experience any of the side effects detailed below stop taking Nitrofurantoin Capsules and consult your doctor.

  • Your lungs may react to Nitrofurantoin Capsules. This may develop quickly, within a week of starting treatment or very slowly, especially in elderly patients. This may produce fever, chills, cough and shortness of breath associated with pneumonia. Scaring due to damaged lung tissue may occur
  • Jaundice (inflammation of the liver causing yellowing of the skin or whites of the eyes)
  • The nerves outside the spinal cord may be affected causing changes to the sense of feeling and the use of muscles. In addition, headache, extreme changes of mood or mental state, confusion, weakness, involuntary eye movement (which may cause the eye to rapidly move from side to side, up and down or in a circle, and lightly blur vision) may occur. These effects may be severe and, in some instances, permanent
  • Raised pressure in the skull (causing severe headaches)
  • Severe reduction in blood cells which can cause weakness, bruising or make infections more likely
  • Blue or purple coloration of the skin due to low oxygen levels. A condition known as cyanosis
  • Symptoms of fever, flu, abdominal pain, diarrhea, blood in your stool and weakness. These could be signs of a condition known as cutaneous vasculitis
  • Symptoms of jaundice, fatigue, abdominal pain, joint pain and swelling. These could be signs of a condition known as autoimmune hepatitis.

Please note that while taking Nitrofurantoin Capsules your urine may become dark yellow or brown coloured. This is quite normal and not a reason to stop taking the medicine.

Other side effects include:

Rare: may affect up to 1 in 1,000 people

  • Loss of consciousness (collapse)
  • Damage to bone marrow causing deficiency of the red blood cells (Anaemia)

Not known: frequency cannot be estimated from the available data

  • Feeling sick (nausea) and headache
  • Loose stools
  • Loss of appetite, stomachache, and being sick (vomiting)
  • Dizziness, drowsiness
  • Blood cells have been affected in some patients. This may result in bruising, delayed clotting of the blood, sore throat, fever, anaemia, and a susceptibility to colds or persistent cold
  • A variety of skin rashes or reactions have occurred in some patients. These may appear as flaking skin, a red rash or fever accompanied by rapid heart rate and severe rash with blistering. Other reactions may include inflammation of salivary glands (causing facial pains), inflammation of the pancreas (causing severe abdominal pain) and joint pains
  • Short-term hair loss
  • Urinary infection by germs which are not sensitive to Nitrofurantoin Capsules.
  • Inflammation of small blood vessel walls, causing skin lesions
  • Liver inflammation due to turn of immune system against liver cells
  • Inflammation of kidney tissue surrounding tubules, causing renal impairment

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: or search for MHRA Yellow Card in the Google Play or Apple App Store.

By reporting side-effects, you can help provide more information on the safety of this medicine


Keep this medicine out of the sight and reach of children.

Do not store above 30°C. Store in the original package to protect from light and moisture.

Do not use this medicine after the expiry date which is stated on the carton after EXP. The expiry date refers to the last day of that month.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use.

These measures will help to protect the environment.

What Nitrofurantoin Capsules contains:

The active substance is Nitrofurantoin. Nitrofurantoin Capsules are available in two strengths, containing either 50mg or 100mg nitrofurantoin.

The other ingredients are talc, maize starch, lactose monohydrate. The capsule shell contains gelatin, sodium lauryl sulphate, quinoline yellow (E104) and titanium dioxide (E171). The printing ink contains shellac and black iron oxide (E172).

What Nitrofurantoin Capsules looks like and contents of the pack:

Nitrofurantoin 50mg capsule is a no. 3 size hard gelatin capsule with an opaque yellow cap and white opaque body. The capsules are printed in edible black ink and bears the monogram “Eaton 008”.

Nitrofurantoin 100mg capsule is a no. 2 size hard gelatin capsule with an opaque yellow cap and yellow opaque body. The capsules are printed in edible black ink and bears the monogram “Eaton 009”.

The capsules are available in blister packs of 30.

Marketing Authorisation Holder:
Mercury Pharmaceuticals Ltd.
Dashwood House
69 Old Broad Street
United Kingdom

Lusomedicamenta S.A.
Sociedade Técnica Farmacêutica
Estrada Consiglieri Pedroso
Queluz de Baixo
2730-055 Barcarena

This leaflet was last revised in January 2024.

Company Contact Details

Dashwood House, 69 Old Broad Street, London, EC2M 1QS, UK


+44 (0)208 588 9131

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