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Nitrofurantoin oral

Updated 2 Feb 2023 | Urinary-tract infections


Oral formulations containing nitrofurantoin

Drugs List

  • nitrofurantoin 100mg capsules
  • nitrofurantoin 100mg tablets
  • nitrofurantoin 25mg/5ml oral suspension sugar-free
  • nitrofurantoin 50mg capsules
  • nitrofurantoin 50mg tablets
  • Therapeutic Indications


    Prophylaxis of recurrent urinary tract infections
    Prophylaxis of urinary infection during instrumental procedures
    Pyelitis - treatment
    Severe chronic recurrent urinary tract infections
    Uncomplicated lower urinary tract infection



    Acute uncomplicated urinary tract infection
    50mg four times a day for seven days.
    Some sources suggest that a three day treatment may be adequate for infections in women.

    Severe chronic recurrent urinary tract infection
    100mg four times a day for seven days.

    Long term prophylaxis
    50mg to 100mg once daily.

    Prophylaxis following surgical procedures
    50mg four times a day for the duration of the procedure and for three days thereafter.


    Children 12 to 18 years
    (See Dosage; Adult).

    Children aged 3 months to 12 years
    Acute urinary tract infection
    3mg/kg daily in four divided doses for three to seven days.

    Suppressive therapy
    1mg/kg once daily.

    Patients with Renal Impairment

    eGFR 30 to 44ml/minute/1.73 metres square
    Nitrofurantoin may be used with caution as short course therapy (three to seven days) for the treatment of uncomplicated lower urinary tract infection with suspected or proven resistance when the benefits of therapy are considered to outweigh the risks.

    eGFR less than 30ml/minute/1.73 metres square


    Children under 3 months
    Acute porphyria
    Breastfeeding - where infant is G6PD deficient
    G6PD deficiency
    Pregnancy at term
    Renal impairment - eGFR below 30ml/minute/1.73m sq

    Precautions and Warnings

    Predisposition to peripheral neuropathy
    Diabetes mellitus
    Electrolyte imbalance
    Folate deficiency
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    Lactose intolerance
    Neurological disorder
    Peripheral neuropathy
    Pulmonary disease
    Renal impairment - eGFR 30 to 44 ml/minute/1.73m sq
    Vitamin B deficiency

    Advise patient ability to drive or operate machinery may be impaired
    Exclude G6PD deficiency before commencing treatment
    Some formulations contain lactose
    Advise patient to take with or after food
    Haematological monitoring required in long term use
    Monitor for signs of neurological toxicity
    Monitor for signs of pulmonary toxicity on long term therapy
    Monitor hepatic function on long term therapy
    Discontinue treatment if haemolysis occurs
    Prolonged use may result in superinfection with non-susceptible organisms
    May affect urinary glucose test for reducing substances
    Discontinue if haematological abnormalities develop
    Discontinue if neurological toxicity occurs
    Discontinue if pulmonary toxicity occurs
    Discontinue if symptoms of hepatic disease occur
    May discolour urine yellow or brown

    Parenchymal infections of unilaterally non-functioning kidneys cannot be effectively treated with nitrofurantoin. A surgical cause of infection should be excluded in recurrent or severe cases.

    Chronic pulmonary reactions may occur and are more common in patients on long term therapy (usually 6 months or more) or the elderly. Lasting effects on pulmonary function may occur even after therapy has stopped.

    Pregnancy and Lactation


    Use nitrofurantoin with caution in pregnancy.
    Nitrofurantoin is contraindicated in pregnancy at term.

    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 drugs, the maternal side effects may adversely affect the 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 pregnant women during labour and delivery because of the possible risk of haemolysis of the infants immature red cells.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Use nitrofurantoin with caution in breastfeeding.

    The manufacturers suggest that infants with known or suspected G6PD deficiency or other erythrocyte enzyme deficiency must be avoided. Briggs suggests the available data show a potential risk to the breastfed infant however the scale of the risk has not yet been established. The Drugs and Lactation Database (LactMed) suggests nitrofurantoin can be used while breastfeeding older infants, but alternate drugs are preferred in mothers of infants under 8 days of age, or infants with G6PD deficiency of any age. Infants should be observed for possible diarrhoea. The time of greatest risk for haemolysis in full term newborns without G6PD deficiency might be as short as 8 days after birth.

    Administration of nitrofurantoin directly to infants under 3 month of age and in those with G6PD deficiency is contraindicated because of potential haemolysis in these infants.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Abdominal pain
    Allergic skin reactions
    Alopecia (transient)
    Aplastic anaemia
    Benign intracranial hypertension
    Blood disorders
    Chest pain
    Cholestatic jaundice
    Discolouration of urine
    Drug fever
    ECG changes
    Erythema multiforme
    Exfoliative dermatitis
    G6PD deficiency anaemia
    Gastro-intestinal disturbances
    Haemolytic anaemia
    Hepatic necrosis
    Hypersensitivity reactions
    Interstitial pneumonitis
    Lupus erythematosus-like syndrome
    Maculopapular rash
    Megaloblastic anaemia
    Motor disturbances
    Optic neuritis
    Peripheral neuropathy
    Pleural effusion
    Psychotic reactions
    Pulmonary fibrosis
    Pulmonary infiltration
    Pulmonary reactions (acute)
    Pulmonary reactions (chronic)
    Sensory disturbances
    Stevens-Johnson syndrome


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: June 2016

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Summary of Product Characteristics: Genfura 50 mg tablets. Genesis Pharmaceuticals Ltd. Revised September 2014.
    Summary of Product Characteristics: Genfura 100 mg tablets. Genesis Pharmaceuticals Ltd. Revised September 2014.
    Summary of Product Characteristics: Nitrofurantoin 25 mg/5 ml oral suspension. Amdipharm Mercury Company Limited. Revised September 2014.
    Summary of Product Characteristics: Nitrofurantoin 50 mg capsules. Amdipharm Mercury Company Limited. Revised September 2014.
    Summary of Product Characteristics: Nitrofurantoin 50 mg tablets. Dr. Reddy's Laboratories (UK) Ltd. Revised May 2016.

    MHRA Drug Safety Update September 2014.
    Available at:
    Last accessed: 03 June 2016

    NICE Evidence Services Available at: Last accessed: 15 September 2017

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Nitrofurantoin. Last revised: 06 November 2015
    Last accessed: 03 June 2016

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