Ampicillin

SCOPE - READ FIRST: this covers the PARENTERAL (IM/IV) route only, which is this page's primary route in current UK practice - the page itself records that ampicillin has been superseded by amoxicillin for most oral indications while intravenous ampicillin remains important for listeria meningitis, enterococcal endocarditis and group B streptococcal infection. The only UK source in this bundle is the injection SPC, which contains NO oral posology, so no oral dose has been drafted; take the oral dose from the SPC of the specific oral product. TABLE-FLATTENING CAVEAT: the SPC's indication/dose table arrived flattened in the fetched text as 'Usual adult dosage (including elderly patients): Septicaemia, endocarditis, osteomyelitis: Peritonitis, intra-abdominal sepsis: Meningitis: 500 mg four to six times a day IM or IV for one to six weeks. 500mg four times a day IM or IV. Adult dosage: 2 g six-hourly IV. Children dosage: 150 mg/kg daily IV in divided doses.' Every number above is verbatim; the pairing of each indication with its dose follows the order in which the two lists appear and should be confirmed against the SPC itself before use. THE US SOURCE IS A DIFFERENT PRODUCT: the openFDA record is for AMPICILLIN AND SULBACTAM (Meitheal Pharmaceuticals, 2025-07-22), whose '1.5 g to 3 g every six hours' figures are ampicillin PLUS sulbactam totals (1 g ampicillin/0.5 g sulbactam to 2 g ampicillin/1 g sulbactam); none of it has been used for dosing here. OTHER ROUTES (eMC §4.2, 'in conjunction with systemic therapy'): intraperitoneal 500 mg daily in up to 10 ml water for injections; intrapleural 500 mg daily in 5-10 ml water for injections; intra-articular 500 mg daily in up to 5 ml water for injections or sterile 0.5% procaine hydrochloride solution; local use in abdominal surgery, 1 g sterile powder sprinkled into the wound extraperitoneally or into muscle layers to prevent wound infection post operatively. NO MAXIMUM ENTERED: the SPC states 'All recommended dosages are a guide only. In severe infections the above dosages may be increased', so it sets no ceiling; the US label's 'total dose of sulbactam should not exceed 4 grams per day' is a ceiling for the other component of a different product and has not been carried over. RECONSTITUTION AND METHOD (eMC §4.2): intramuscular - 'Add 1.5 ml water for injections to 500mg vial contents'; intravenous - 'Dissolve 500 mg in 10 ml water for injections. Administer by slow injection (three to four minutes). Ampicillin may also be added to infusion fluids or injected, suitably diluted, into the drip tube over a period of three to four minutes.' SODIUM: 'This medicine contains 33.7 mg of sodium per vial, equivalent to 1.7% of the WHO recommended maximum daily intake of 2 g sodium for an adult.'

eMC §4.2, verbatim: 'Children dosage: 150 mg/kg daily IV in divided doses.' This figure sits in the MENINGITIS row of the SPC's dose table and should be treated as the meningitis dose rather than a general paediatric dose - see the table-flattening caveat in the adult notes. For routine (non-meningitis) paediatric dosing the SPC gives a fraction rule, not a per-kg rule: 'Half adult routine dosage for children under 10 years' - which cannot be expressed as a per-kg figure and so is recorded here only. No neonatal dose, no number of divided doses per day, no dose interval and no paediatric maximum are given anywhere in this bundle, and no age band is attached to the 150 mg/kg/day figure. CONCENTRATION: 50 mg/mL is the intravenous reconstitution from the SPC method of administration ('Dissolve 500 mg in 10 ml water for injections'); the intramuscular reconstitution is different (add 1.5 ml water for injections to a 500 mg vial), so this concentration applies to the IV route only. The US source in this bundle is ampicillin WITH SULBACTAM and its 300 mg/kg/day paediatric figure is a combination total (200 mg ampicillin plus 100 mg sulbactam per kg per day) - it has not been used here. Verify the paediatric dose, the dosing interval and any neonatal dose against a children's formulary.