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Ampicillin parenteral


Powder for solution for injection containing ampicillin

Drugs List

  • ampicillin 500mg powder for solution for injection
  • Therapeutic Indications


    Antibiotic sensitive infections
    Bacterial meningitis
    Group B streptococcal infection

    Ampicillin is a broad spectrum penicillin indicated for a wide range of bacterial infections caused by ampicillin-sensitive organisms. Types of infection include:

    Ear, nose and throat infections
    Urinary tract infections
    Gynaecological infections
    Enteric fever
    Gastrointestinal infections

    The sterile powder may be applied directly into wounds extraperitoneally to prevent infection following abdominal surgery.

    Parenteral administration of ampicillin is indicated when oral dosing is not appropriate.


    All recommended doses are a guide only. Dosage may need to be increased in severe infections.


    Ampicillin-sensitive infections
    To be given by intravenous or intramuscular injection.
    500mg every 4 to 6 hours.
    Maximum dose: 6g daily.

    2g every 4 hours by intravenous infusion.


    Ampicillin-sensitive infections
    Children aged 12 to 18 years
    (See Dosage; Adult)

    Children aged 1 month to 12 years
    To be given by intravenous injection or infusion.
    25mg/kg to 50mg/kg every 6 hours.
    Maximum dose: 1g every 6 hours.

    Enterococcal endocarditis, group B streptococcal infection, listeral meningitis
    To be given by intravenous injection or infusion.
    50mg/kg every 4 to 6?hours.
    Maximum dose: 2g every 4?hours.


    Ampicillin-sensitive infections
    Neonate aged 21 to 28 days 30mg/kg every 6 hours. The dose can be doubled in case of severe infection. Neonate aged 7 to 21 days 30mg/kg every 8 hours. The dose can be doubled in case of severe infection. Neonate aged under 7 days 30mg/kg every 12 hours. The dose can be doubled in case of severe infection.

    Enterococcal endocarditis, group B streptococcal infection
    Neonate aged 21 to 28 days
    50mg/kg every 6?hours.
    Neonate aged 7 to 21 days
    50mg/kg every 8?hours.
    Neonate aged under 7 days
    50mg/kg every 12?hours.

    Listerial meningitis
    Neonate aged 21 to 28 days
    100mg/kg every 6?hours.
    Neonate aged 7 to 21 days
    100mg/kg every 8?hours.
    Neonate aged under 7 days
    100mg/kg every 12?hours.

    Patients with Renal Impairment

    Creatinine clearance of 20 to 30mL/minute: Reduce normal dose to two thirds.
    Creatinine clearance below 20mL/minute: Reduce normal dose to one third.

    In patients with severe renal impairment, do not exceed 1g every 8 hours.

    The Renal Drug Handbook suggests the following doses based on GFR (mL/minute):
    GFR of 20 to 50mL/minute: (See Dosage; Adult).
    GFR of 10 to 20mL/minute: 250mg to 2g every 6 hours.
    GFR of less than 10mL/minute: 250mg to 1 every 6 hours.

    Dialysed patients
    An additional dose should be administered after the dialysis session.


    May be administered by the following routes:

    Intramuscular injection
    Intravenous injection (slow injection over 3-4 minutes)
    Intravenous infusion (add to infusion fluids or inject, after dilution, into the drip tube over 3-4 minutes)
    Intraperitoneal injection
    Intrapleural injection
    Intra-articular injection
    Extraperitoneal application of the sterile powder


    None known

    Precautions and Warnings

    Allergic disposition
    Cytomegalovirus infection
    Infectious mononucleosis
    Restricted sodium intake
    Lymphatic leukaemia
    Renal impairment - creatinine clearance below 10ml/minute

    Reduce dose in patients with severe renal impairment
    Sodium content of formulation may be significant
    Before initiating therapy enquire about previous hypersensitivity reactions
    Consult national/regional policy on the use of anti-infectives
    Erythematous rash common in glandular fever, CMV inf, lymphocytic leukaemia
    Prolonged use may result in superinfection with non-susceptible organisms
    May affect non-enzyme methods of urine glucose testing
    Discontinue if drug-related rash or other hypersensitivity reactions occur

    Pregnancy and Lactation


    Ampicillin is considered safe for use during pregnancy.

    Ampicillin has been used extensively since 1961 and its suitability in human pregnancy has been well documented in clinical studies.

    Animal studies have demonstrated no teratogenic effects.

    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 ampicillin with caution in breastfeeding.

    Trace quantities of ampicillin can be detected in breast milk. The Drugs and Lactation database (LactMed) suggest ampicillin is acceptable to use during breastfeeding. Schaefer suggests penicillin derivatives and cephalosporins are the antibiotics of choice during breastfeeding.

    Adverse effects are rare but the nursing infant can experience bowel flora changes, allergy, sensitisation, and abnormal culture results when pyrexia of unknown origin occurs.

    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

    Antibiotic-associated colitis
    Cholestatic jaundice
    CNS toxicity
    Erythema multiforme
    Haematological reactions
    Haemolytic anaemia
    Haemorrhagic colitis
    Hypersensitivity reactions
    Increase in serum transaminases
    Interstitial nephritis
    Joint pain
    Prolonged bleeding
    Prothrombin time increased
    Pseudomembranous colitis
    Serum sickness-like reactions
    Stevens-Johnson syndrome
    Toxic epidermal necrolysis

    Effects on Laboratory Tests

    Enzymatic glucose oxidase methods of testing for glucose in the urine should be used during ampicillin treatment. Chemical methods may lead to false-positive readings due to high urinary concentrations of ampicillin.


    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: August 2013

    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.

    The Renal Drug Handbook. 3rd edition. (2009) ed. Ashley, C and Currie, Radcliffe Publishing Ltd, Abingdon.

    Summary of Product Characteristics: Ampicillin 500mg Vials. Essential Generics. Revised November 2017.

    NICE Evidence Services Available at: Last accessed: 185 July 2017

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Ampicillin. Last revised: January 24, 2013.
    Last accessed: August 6, 2013.

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