Nitrofurantoin 25mg/5ml Oral Suspension

Nitrofurantoin is indicated for the treatment of and prophylaxis against acute or recurrent, uncomplicated lower urinary tract infections either spontaneous or following surgical procedures when due to susceptible micro-organisms (see section 4.4 and 5.1).

Consideration should be given to official guidance on the appropriate use of antibacterial agents.

Posology

Dosage:

Adults

Acute Uncomplicated Urinary Tract Infections: 50mg four times daily for seven days.

Severe Chronic Recurrence: 100mg four times a day for seven days.

Long Term Suppression: 50mg - 100mg once a day.

Prophylaxis: 50mg four times daily for the duration of procedure and 3 days thereafter.

Paediatric population

Children and Infants over three months of age

For children under 25 kg body weight consideration should be given to the use of Nitrofurantoin Suspension.

Acute Urinary Tract Infections: 3mg/kg/day in four divided doses for seven days.

Suppressive: 1mg/kg, once a day.

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 (Section 4.8).

Renal impairment

Nitrofurantoin is contraindicated in patients with renal dysfunction and in patients with an eGFR of less than 45 ml/minute (see sections 4.3 & 4.4).

Method of administration:

For Oral use.

This medicine should always be taken with food or milk. Taking Nitrofurantoin with a meal improves absorption and is important for optimal efficacy. It is recommended to shake well before use, until complete resuspension.

Patients with known hypersensitivity to nitrofurantoin, other nitrofurans or to any of the excipients listed in section 6.1.

Patients suffering from renal dysfunction with an eGFR of less than 45 ml/minute. 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.

G6PD deficiency (including pregnancy at term, and breast-feeding of affected infants, Third trimester: May produce neonatal haemolysis if used at term, only small amounts are present in milk but could be enough to produce haemolysis in G6PD deficient infants), 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.

Nitrofurantoin is not effective for the treatment of parenchymal infections of unilaterally non-functioning kidney. A surgical cause for infection should be excluded in recurrent or severe cases.

Since pre-existing conditions may mask 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 ( paranesthesia).

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 may occur commonly in elderly patients. Close monitoring of the pulmonary conditions of patients receiving long-term therapy is warranted (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).

Patients should be monitored closely for signs of hepatitis (particularly in long terms use).

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 sign of haemolysis in those with suspected glucose-6-phosphate dehydrogenase deficiency.

For long-term treatment, monitor patients closely for evidence of hepatitis or pulmonary symptoms or other evidence of toxicity.

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.

Discontinue treatment with Nitrofurantoin if otherwise unexplained pulmonary, hepatic, haematological or neurological syndromes occur.

Excipient Warnings

This product contains:

Methyl parahydroxybenzoate which may cause allergic reaction (possibly delayed)

Propyl parahydroxybenzoate which may cause allergic reaction (possibly delayed)

Glycerol which may cause headache, stomach upset and diarrhoea.

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

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:

Oestrogens: Antibacterials that do not induce liver enzymes possibly reduce contraceptive effect of oestrogens (risk probably small, Interactions of combined oral contraceptives may also apply to combined contraceptive patches).

Typhoid Vaccine (oral): Antibacterials inactivate oral typhoid vaccine.

Pregnancy

Animal studies with Nitrofurantoin have shown no teratogenic effects, however study in rats has shown reproductive toxicity (see section 5.3).

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 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

Nitrofurantoin 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.

Very common (≥1/10)

Common (≥1/100 to <1/10)

Uncommon (≥1/1000 to <1/100)

Rare (≥1/10,000 to <1/1,000)

Very Rare (<1/10,000)

Not known (cannot be estimated from the available data)

*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.

Reporting of suspected adverse reactions

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 at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Symptoms and signs of overdose include gastric irritation, nausea and vomiting.

There is no known specific antidote. However, Nitrofurantoin can be hemodialyzed in cases of recent ingestion. Standard treatment is by induction of emesis or by gastric lavage. Monitoring of full blood count, liver function, and pulmonary function tests are recommended. A high fluid intake should be maintained to promote urinary excretion of the drug.

Pharmacotherapeutic group: Antibacterials for systemic use Nitrofuran derivatives,

ATC code: J01XE01

Mechanism of action:

Nitrofurantoin is a broad-spectrum antibacterial agent, active against the majority of urinary pathogens. The wide range of enzymes including bacterial flavoproteins to reactive intermediates which bind to bacterial ribosomes and inhibit several bacterial enzymes involved in the synthesis of DNA, RNA and other metabolic enzymes.

PK/PD relationship: There are no recent pharmacokinetic data available or studies that link pharmacokinetic (PK) with pharmacodynamic (PD) information. The PK/PD index and correlation with outcome is not known.

Mechanism (s) of resistance: Nitrofurantoin acts at multiple targets in the bacterial cell and resistance is uncommon. Resistance is thought to be due to loss of intracellular nitroreductase activity via sequential mutations in the DNA regions encoding these enzymes.

Breakpoints:

Susceptibility interpretive Criteria for Nitrofurantoin (EUCAST v. 9.0, valid from 2019-01-01)

Susceptibility:

The prevalence of resistance may vary geographically and with time for selected species and local information on resistance is desirable, particularly when treating severe infections. As necessary, expert advice should be sought when the local prevalence of resistance is such that the utility of the agent in at least some types of infection is questionable.

Absorption

Orally administered Nitrofurantoin is readily absorbed in the upper gastrointestinal tract and is rapidly excreted in the urine. Blood concentrations at therapeutic dosages are usually low.

Elimination

Maximum urinary excretion usually occurs 2-4 hours after administration of Nitrofurantoin. Urinary drug dose recoveries of about 40-45% are obtained. It has an elimination half-life of about 30 minutes

The available genotoxicity data indicate that nitrofurantoin is a mutagen. Two-year carcinogenicity studies in rats and mice reported carcinogenic effects. The relevance of the genotoxic and carcinogenic potential of nitrofurantoin to human is unknown. Extensive clinical use of Nitrofurantoin over 65 years has not found any conclusive evidence for carcinogenic effects at therapeutic dosages.

In rats, at high doses a temporary halt in spermatogenesis was observed. No decreased fertility was observed in animal studies.

Methyl parahydroxybenzoate

Propyl parahydroxybenzoate

Polysorbate 20

Glycerol

Carbomer

Sucralose

Apricot flavour

Sodium hydroxide

None known

3 years

After first opening: 3 months

This medicinal product does not require any special storage conditions before opening.

After first opening do not store above 25°C and use within 3 months.

Bottle: 300 ml in Amber (Type III) glass

Closure: LDPE, child-resistant screw cap

Dosing devices: One 5 ml oral medication syringe (plastic dosing pipette) with 0.1ml graduation and the neck fitted syringe adaptor for the bottle or one double plastic 2.5/5.0 ml spoon

No special requirements for disposal.

Any unused medicinal product or waste material should be disposed of in accordance with local requirements.