Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Pharmacy Guide
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules
⚠ This medicine appears to have been discontinued
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Nitrofurantoin may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
What it is and what it is used for
for
Nitrofurantoin (the active substance in Nitrofurantoin CNX Therapeutics 100mg prolonged-release capsules) is an antibiotic. It is used to prevent and treat infections of the bladder, kidney and other parts of the urinary tract. 2.
What do you need to know before you take Nitrofurantoin CNX
Do not take Nitrofurantoin CNX
- if you are allergic to nitrofurantoin, other nitrofurans or 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 have porphyria (blood disorder)
- if you have G6PD (glucose-6-phosphate dehydrogenase) deficiency
- do not use in infants 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 or pharmacist before taking Nitrofurantoin CNX:
- if you have diabetes
- if you are suffering from any illness causing severe weakness Medical Checks
Your doctor will watch carefully for any effects on the liver, lungs, blood or nervous system. Nitrofurantoin may interfere with the results of some tests for glucose in the urine. Children This medicine is not suitable for children under 12 years of age. Other medicines and Nitrofurantoin CNX Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. This includes herbal medicines and other medicines you've bought without a prescription. Some of these medicines can change the effect of Nitrofurantoin CNX.
- antacids containing magnesium trisilicate may reduce the absorption of nitrofurantoin.
- tell your doctor if you are taking an anti-gout medicine such as probenecid and sulfinpyrazone. Some of these medicines can reduce the effect of Nitrofurantoin CNX.
- if you are prescribed a quinolone antibacterial medicine, tell the doctor that you are also taking this medicine. Combining these medicines can reduce the effectiveness of both.
- carbonic anhydrase inhibitors (such as acetazolamide for the treatment of glaucoma).
- the oral typhoid vaccine may not work when you are taking this medicine. Discuss this with your doctor.
- urine glucose tests can be affected by this medicine. If you are not sure about any of these medicines, consult your doctor or pharmacist. 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. Pregnancy As far as it is known, nitrofurantoin may be used during pregnancy. However, this medicine should not be used during labour and delivery because there is a possibility that use at this stage may affect the baby. Always follow your doctor's instructions carefully. Breast-feeding If you wish to breastfeed, consult your doctor first because this medicine passes into breast milk and may be harmful to infants under 3 months of age. Driving and using machines This medicine may cause dizziness and drowsiness (sleepiness). You should not drive or operate machinery if you are affected this way until such symptoms go away. Nitrofurantoin CNX contains lactose and sucrose This medicine contains lactose and sucrose which are types of sugars. If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine. 3.
How to take it
Nitrofurantoin CNX
Always take this medicine exactly as your doctor or pharmacist has told you. You should check with your doctor or pharmacist if you are not sure. The recommended dose is: Adults and children over 12 years old: 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 bladder infections: One capsule twice a day for seven days
•
For prevention of bladder infections during surgery: One capsule twice a day on the day of the operation and three days thereafter.
Method of administration Nitrofurantoin CNX is to be taken by mouth: the capsule should be swallowed whole, with a meal or with some milk or yogurt. Thus, this medicine is better tolerated and gastrointestinal (stomach and intestines) reactions are minimized. If you take more Nitrofurantoin CNX than you should Contact your doctor or pharmacist immediately or go to the emergency department of the nearest hospital. Always take any remaining capsules with you, as well as the container and label, so that the medical staff know what you have taken. Vomiting and stomach problems may occur when you take too much of this medicine. If you forget to take Nitrofurantoin CNX Normally you should take one capsule twice a day. If you miss a dose, take it as soon as possible. If it is almost time for the next dose, skip the forgotten dose and go back to your regular schedule. Do not take a double dose to make up for a forgotten capsule. If you have forgotten several doses in a row, please contact your doctor. He will probably prescribe a new treatment. If you stop taking Nitrofurantoin CNX 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 stop the treatment too soon, the symptoms may return very quickly and this may be undesirable and unpleasant for you. That is why it is important that you complete the treatment. If you have any further questions on the use of this medicine, ask your doctor or pharmacist. 4.
Possible side effects
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 CNX. All medicines can cause allergic reaction 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 this medicine and go to a doctor immediately. If you experience any of the side effects detailed below stop taking Nitrofurantoin CNX and consult your doctor.
- Problems with your lungs. This can happen quickly, within one week after the start of treatment, or very slowly, especially in the elderly and can lead to fever, shivering, coughing and shortness of breath associated with pneumonia and/or tissue damage.
- 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, weakness, blurred vision may occur. These effects may be severe and is 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.
- Symptoms of fever, flu, abdominal pain, diarrhoea, blood in your stool and weakness. These could be signs of a condition known as cutaneous vasculitis.
- Symptoms of fatigue, abdominal pain, joint pain and swelling. These could be signs of a condition known as hepatitis. Other side effects include: Rare (may affect up to 1 in 1,000 people)
• • •
Loss of consciousness (collapse) Blue or purple coloration of the skin due to low oxygen levels. A condition known as cyanosis. Severe reduction in blood cells which can cause weakness, bruising or make infections more likely. A condition known as aplastic anaemia.
Not known (frequency cannot be estimated from the available data)
- Feeling sick (nausea) and headache
- Diarrhoea
- Loss of appetite, stomach ache, and being sick (vomiting)
- Dizziness, drowsiness (sleepiness)
- 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 gland (causing severe abdominal pain) and joint pains
- Short-term hair loss
- Urinary infection by germs which are not sensitive to Nitrofurantoin CNX
- 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
- Jaundice (inflammation of the liver causing yellowing of the skin or whites of the eyes).
- Confusion
- Depression
- Very happy (euphoria)
- Psychotic reactions
- Urine may become coloured dark yellow or brown coloured. This is quite normal and not a reason to stop taking the medicine. Reporting of side effects If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard 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. 5.
How to store it
Nitrofurantoin CNX
Keep this medicine out of the sight and reach of children. Do not store above 25 °C. Do not use this medicine after the expiry date (EXP) which is stated on the carton and/or blister. 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. 6.
Contents of the package and other information
What Nitrofurantoin CNX contains The active substance in this medicine is nitrofurantoin. Each prolonged release hard capsule contains equivalent of 100mg nitrofurantoin in the form of nitrofurantoin macrocrystals and nitrofurantoin monohydrate. The other ingredients are:
• • •
capsule content: talc, maize starch, carbomers, povidone, lactose monohydrate, sucrose, magnesium stearate. capsule shell: iron oxide yellow, iron oxide black, titanium dioxide (E 171), indigo carmine, gelatin. printing ink: shellac, propylene glycol (E 1520), strong ammonia solution, water, potassium hydroxide, titanium dioxide (E 171).
What Nitrofurantoin CNX looks like and contents of the pack Nitrofurantoin CNX Therapeutics100 mg prolonged-release capsules are 19.4 mm long and 6.9 mm wide capsules with blue opaque cap debossed with "NTRF" in white ink and yellow opaque body. Carton box containing standard PVC-PCTFE/Alu blisters with 2, 6, 7, 14 or 20 capsules each. Not all pack sizes may be marketed. Marketing Authorization Holder CNX Therapeutics Limited, 3 Bunhill Row London EC1Y 8YZ, United Kingdom Manufacturer Pharmadox Healthcare Ltd. KW20A Kordin Industrial Park, Paola, PLA 3000 Malta KeVaRo Group Ltd. 9, Tsaritsa Eleonora Str., Office 23, Sofia, 1618, Bulgaria This leaflet was last revised in May/2024.
Frequently asked questions about Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules
How do I take Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules?
Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules comes as capsule containing 100mg. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.
What is the active substance in Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules?
The active substance in Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules is nitrofurantoin.
Are there equivalent medicines to Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules?
Medicines with the same active substance, strength and form include: Nitrofurantoin 100 mg Capsules, Nitrofurantoin 100 mg Hard Capsules, Nitrofurantoin 100 mg capsules. In total there are 9 equivalent products. They are interchangeable only if your prescriber or pharmacist says so.
Where does this information come from?
This leaflet reproduces the patient information leaflet approved for Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Can I get Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules without a prescription?
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
About this leaflet
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
- Source: electronic medicines compendium (emc), Datapharm
- Active substance: nitrofurantoin
- Official document: view the original leaflet on emc →
⚕For healthcare professionals — Summary of Product Characteristics (SmPC)Full SmPC: dosage, interactions, contraindications, warnings+
4.1. Therapeutic indications
For the treatment of and prophylaxis against acute or recurrent, uncomplicated lower urinary tract infections or pyelitis either spontaneous or following surgical procedures. It is indicated in adults, children and infants over 12 years of age.
Nitrofurantoin is specifically indicated for the treatment of infections when due to susceptible strains of Escherichia coli, Enterococci, Staphylococci, Citrobacter, Klebsiella and Enterobacter.
Most strains of Proteus and Serratia are resistant. All Pseudomonas strains are resistant.
Nitrofurantoin is not indicated for the treatment of associated renal cortical or perinephric abscesses.
4.2. Posology and method of administration
Posology
Adults and children over 12 years of age.
The dose should be taken with food or milk (e.g. at meal times).
Acute or recurrent uncomplicated UTI and pyelitis -100mg twice daily for seven days.
Surgical Prophylaxis - 100 mg twice daily on the day of the procedure and 3 days thereafter.
Elderly
Provided there is no significant renal impairment, in which nitrofurantoin is contraindicated, the dosage should be that for any normal adult.
See precaution and risks to elderly patients associated with long term therapy (see section 4.8).
Children under 12 years
Nitrofurantoin CNX Therapeutics 100mg Prolonged-Release Capsules is a fixed dosage and is therefore not suitable for children under 12 years.
Renal impairment
Nitrofurantoin is contraindicated in patients with renal dysfunction and in patients with an eGFR below of less than 45 ml/minute (see sections 4.3 & 4.4).
Method of administration
For oral use
4.3. Contraindications
• Hypersensitivity to the active substance, other nitrofurans or to any of the excipients listed in section 6.1.
• Patients suffering from renal dysfunction with an eGFR below 45 ml/minute.
• G6PD deficiency (see also Section 4.6)
• Acute porphyria.
• In infants under three months of age as well as pregnant patients at term (during labour and delivery) because of the theoretical possibility of haemolytic anaemia in the foetus or in the newborn infant due to immature erythrocyte enzyme systems.
4.4. Special warnings and precautions for use
Nitrofurantoin is not effective for the treatment of parenchymal infections of a unilaterally functioning kidney. A surgical cause for infection should be excluded in recurrent or severe cases.
Nitrofurantoin may be used with caution as short-course therapy only for the treatment of uncomplicated lower urinary tract infection in individual cases with an eGFR between 30-44 ml/min to treat resistant pathogens, when the benefits are expected to outweigh the risks.
Since pre-existing conditions may mask hepatic or pulmonary adverse reactions, nitrofurantoin should be used with caution in patients with pulmonary disease, hepatic dysfunction, neurological disorders and allergic diathesis.
Peripheral neuropathy and susceptibility to peripheral neuropathy, which may become severe or irreversible has occurred and may be life threatening. Therefore, treatment should be stopped at the first signs of neural involvement (paraesthesiae).
Nitrofurantoin should be used with caution in patients with anaemia, diabetes mellitus, electrolyte imbalance, debilitating conditions, and vitamin B (particularly folate) deficiency.
Pulmonary adverse reactions
Acute, subacute and chronic pulmonary reactions have been observed in patients treated with nitrofurantoin. If these reactions occur, nitrofurantoin should be discontinued immediately. Signs of pulmonary damage include difficulty and or pain when breathing, shortness of breath and coughing up blood or mucus.
Chronic pulmonary reactions
Chronic pulmonary reactions (including pulmonary fibrosis and diffuse interstitial pneumonitis) can develop insidiously and can often occur in elderly patients. Close monitoring of the lung diseaseof patients receiving long-term therapy is indicated (especially in the elderly).
Acute pulmonary reactions
Pulmonary reactions may be acute and usually occur within the first week of treatment. Increased vigilance for respiratory symptoms in patients who have just started therapy is warranted (especially in the elderly).
Urine may be coloured yellow or brown after taking Nitrofurantoin. Patients on Nitrofurantoin are susceptible to false positive urinary glucose (if tested for reducing substances).
Nitrofurantoin should be discontinued at any signs of haemolysis in those with suspected glucose-6-phosphate dehydrogenase deficiency.
Gastrointestinal reactions may be minimised by taking the drug with food or milk, or by adjustment of dosage.
Hepatotoxicity
Hepatic reactions, including hepatitis, autoimmune hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis, occur rarely. Fatalities have been reported. The onset of chronic active hepatitis may be insidious, and patients should be monitored periodically for changes in biochemical tests that would indicate liver injury. If hepatitis occurs, the drug should be withdrawn immediately and appropriate measures should be taken.
For long term treatment monitor the patient closely for appearance of hepatic or pulmonary symptoms and other evidence of toxicity.
Discontinue treatment with nitrofurantoin if otherwise unexplained pulmonary, hepatotoxic, haematological or neurological syndromes occur.
Excipients
Nitrofurantoin CNX Therapeutics 100 mg prolonged-release capsules contain lactose monohydrate and sucrose. Patients with rare hereditary problems of galactose intolerance, fructose intolerance, total lactase deficiency, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine.
4.5. Interaction with other medicinal products and other forms of interaction
1. Increased absorption with food or agents delaying gastric emptying.
2. Decreased absorption with magnesium trisilicate.
3. Decreased renal excretion of Nitrofurantoin by probenecid and sulfinpyrazone.
4. Decreased anti-bacterial activity by carbonic anhydrase inhibitors and urine alkalisation.
5. Anti-bacterial antagonism by quinolone anti-infectives.
6. Interference with some tests for glucose in urine.
7. As Nitrofurantoin belongs to the group of Antibacterials, it will have the following resulting interactions:
• Typhoid Vaccine (oral): Antibacterials inactivate oral typhoid vaccine.
4.6. Fertility, pregnancy and breastfeeding
Pregnancy
Animal studies with nitrofurantoin have shown no teratogenic effects. Nitrofurantoin has been in extensive clinical use since 1952 and its suitability in human pregnancy has been well documented. However, as with all other drugs, the maternal side effects may adversely affect course of pregnancy. The drug should be used at the lowest dose as appropriate for a specific indication, only after careful assessment.
Nitrofurantoin is however contraindicated in infants under three months of age and in pregnant women during labour and delivery because of the possible risk of haemolysis of the infants immature red cells.
Breast-feeding
Breast feeding an infant known or suspected to have an erythrocyte enzyme deficiency (including G6PD deficiency), must be temporarily avoided, since Nitrofurantoin is detected in trace amounts in breast milk.
Fertility
No data available
4.7. Effects on ability to drive and use machines
Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules may cause dizziness and drowsiness. Patients should be advised not to drive or operate machinery if affected in this way until such symptoms go away.
4.8. Undesirable effects
A tabulated list of undesirable effects is outlined below:
The undesirable effects are listed according to organ systems and following frequencies:
Rare (≥1/10,000 to <1/1,000)
Not known (cannot be estimated from the available data)
System organ class
Frequency
Adverse reaction
Infections and infestations
Not known
Superinfections by fungi or resistant organisms such as Pseudomonas. However, these are limited to the genitourinary tract
Blood and lymphatic system disorders
Rare
Not known
Aplastic anaemia
Agranulocytosis, leucopenia, granulocytopenia, haemolytic anaemia, thrombocytopenia,glucose¬6-phosphatedehydrogenase deficiency anaemia, megaloblasticanaemia and eosinophilia
Immune system disorders
Not known
Anaphylaxis, , angioneuroticoedema , cutaneous vasculitis and allergic skin reactions
Psychiatric disorders
Not known
psychotic reactions, depression, euphoria, confusion
Nervous system disorders
Not known
Benign intracranial hypertension, peripheral neuropathy including optic neuritis (sensory as well as motor involvement), nystagmus, vertigo, dizziness, headache and drowsiness.
Cardiac disorders
Rare
Collapse and cyanosis
Respiratory, thoracic and mediastinal disorders
Not known
Pulmonary fibrosis; possible association with lupus-erythematous-like syndrome.
acute pulmonary reactions *
subacute pulmonary reactions, *
chronic pulmonary reactions, *
cough, dyspnoea,
Gastrointestinal disorders
Not known
Sialaodenitis, pancreatitis, anorexia, emesis, abdominal pain, diarrhea and nausea
Hepatobiliary disorders
Not known
Chronic active hepatitis**, hepatic necrosis, autoimmune hepatitis, cholestatic jaundice
Skin and subcutaneous tissue disorders
Not known
Lupus-like syndrome associated with pulmonary reaction.
Drug Rash With Eosinophilia And Systemic Symptoms (DRESS syndrome), exfoliative dermatitis and erythema multiforme (including Stevens-Johnson Syndrome), maculopapular, erythematous or eczematous eruptions, urticaria, rash, and pruritis, Transient alopecia
Renal and urinary disorders
Not known
Interstitial nephritis, yellow or brown discolouration of urine,
General disorders and administration site conditions
Not known
Asthenia, fever, chills, drug fever and arthralgia
Investigations
Not known
False positive urinary glucose
* Acute pulmonary reactions are commonly manifested by fever, chills, cough, chest pain, dyspnoea, pulmonary infiltration with consolidation or pleural effusion on chest x-ray, and eosinophilia. In subacute pulmonary reactions, fever and eosinophilia occur less often than in the acute form.
Chronic pulmonary reactions occur rarely in patients who have received continuous therapy for six months or longer and are more common in elderly patients. Changes in ECG have occurred, associated with pulmonary reactions
**Can be fatal
Reporting of suspected side effects
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme
Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
4.9. Overdose
Symptoms
Symptoms and signs of overdose include stomach irritation, nausea and vomiting.
Management
There is no specific antidote, however, nitrofurantoin can be haemodialysed if necessary. Standard treatment consists in the induction of emesis or gastric lavage in cases of recent ingestion (within one hour). Monitoring of full blood count, hepatic function and pulmonary function tests are recommended. A high fluid intake should be maintained to promote urinary excretion of nitrofurantoin.
💬 Ask about this leaflet
Ask anything about Nitrofurantoin CNX Therapeutics 100 mg Prolonged-Release Capsules. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.
Medicines containing Nitrofurantoin
- Nitrofurantoin 100 mg Capsules
- Nitrofurantoin 100 mg hard capsules
- Nitrofurantoin 100 mg prolonged release capsules
- Nitrofurantoin 100 mg Tablets
- Nitrofurantoin 100mg Capsules
- Nitrofurantoin 100mg Capsules, Hard
- Nitrofurantoin 50 mg capsules
- Nitrofurantoin 50 mg Hard Capsules
- Nitrofurantoin 50 mg Tablets
- Nitrofurantoin 50mg Capsules
- Nitrofurantoin 50mg Capsules, Hard
- Nitrofurantoin Mercury Pharma 100mg Prolonged-Release Capsules
- Nitrofurantoin RPH Pharma 100 mg prolonged-release capsules