Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Third-generation cephalosporin Pregnancy: No adequate data to assess harmfulness in pregnancy; crosses the placental barrier. Should not be used during pregnancy unless the anticipated benefit outweighs any potential risks.

Cefotaxime

Brand names: Claforan

Cefotaxime is a third-generation parenteral cephalosporin antibacterial used for serious infections including meningitis, septicaemia and pneumonia.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1 to 2 g every 12 hours (usual total 2 to 6 g daily)
Route: Intravenous bolus injection, intravenous infusion, or intramuscular injection
Frequency: Every 12 hours; for severe infections 2 to 3 g every 6 to 8 hours
Max: 12 g daily
Adults and adolescents over 12 years: usual dose 2 to 6 g cefotaxime daily, divided into two single doses every 12 hours. Common infection with a sensitive bacterium 1 g every 12 h; several sensitive/moderately sensitive bacteria 1 to 2 g every 12 h; severe or non-localised infection 2 to 3 g as a single dose every 6 to 8 h (max 12 g/day). Gonorrhoea: single 500 mg to 1 g IM or IV. Bacterial meningitis (adults): 9 to 12 g daily divided every 6 to 8 h (3 g three to four times daily). Perioperative prophylaxis: 1 to 2 g single dose. Combine with an anti-anaerobic agent for intra-abdominal infections.

Paediatric dose

Dose: 100 mg/kg
Route: Intravenous or intramuscular
Frequency: Daily dose divided 12- to 6-hourly
Max: 200 mg/kg/day (life-threatening situations)
Term newborn (0 to 28 days), infants and children up to 12 years: 50 to 100 to 150 mg/kg/day depending on severity, given 12- to 6-hourly; in life-threatening situations may be raised to 200 mg/kg/day with careful attention to renal function (especially newborns 0 to 7 days). Premature infants: 50 mg/kg/day divided into 2 to 4 doses; this maximum should not be exceeded. Bacterial meningitis (children): 150 to 200 mg/kg/day divided every 6 to 8 h; newborns 0 to 7 days 50 mg/kg every 12 h, 7 to 28 days 50 mg/kg every 8 h. Cefotaxime reconstituted with lidocaine must not be given to children in the first year of age.

Dose adjustments

Renal

Adults with creatinine clearance <=5 mL/min: initial dose as usual, then maintenance dose halved without changing the dosing frequency. Haemodialysis/peritoneal dialysis: IV 500 mg to 2 g given at the end of each dialysis session and repeated every 24 hours.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

Term newborn (0 to 28 days), infants and children up to 12 years: 50 to 100 to 150 mg/kg/day depending on severity, given 12- to 6-hourly; in life-threatening situations may be raised to 200 mg/kg/day with careful attention to renal function (especially newborns 0 to 7 days). Premature infants: 50 mg/kg/day divided into 2 to 4 doses; this maximum should not be exceeded. Bacterial meningitis (children): 150 to 200 mg/kg/day divided every 6 to 8 h; newborns 0 to 7 days 50 mg/kg every 12 h, 7 to 28 days 50 mg/kg every 8 h. Cefotaxime reconstituted with lidocaine must not be given to children in the first year of age.

Verify in a children's formulary

Contraindications

  • Hypersensitivity to the active substance or to other cephalosporins
  • Previous immediate and/or severe hypersensitivity reaction to penicillin or any beta-lactam antibiotic
  • Cefotaxime constituted with lidocaine must never be used: by the intravenous route; in infants under 30 months; with a previous history of hypersensitivity to this product; in patients with an unpaced heart block; or in patients with severe heart failure

Side effects

  • Diarrhoea
  • Nausea and vomiting
  • Rash, pruritus, urticaria
  • Increase in liver enzymes (ALAT, ASAT, LDH, gamma-GT and/or alkaline phosphatase) and/or bilirubin
  • Injection site reactions (pain, phlebitis/thrombophlebitis)

Interactions

  • Aminoglycosides: risk of decreased renal function / raised creatinine when co-prescribed; must not be mixed with cefotaxime in the same syringe or perfusion fluid

Clinical monograph

How it works

As a beta-lactam it inhibits bacterial cell-wall synthesis by binding penicillin-binding proteins, giving a bactericidal action against susceptible Gram-positive and Gram-negative organisms.

Prescribing in practice

  • Avoid in patients with a history of immediate hypersensitivity to penicillins or other beta-lactams because of the risk of cross-reactivity.
  • It penetrates the cerebrospinal fluid well, making it a recognised option for bacterial meningitis where susceptibility is appropriate.
  • Dose adjustment is required in significant renal impairment, in line with the SPC.

Monitoring

Monitor renal function and clinical response, particularly during prolonged courses or in critically ill or renally impaired patients.

Counselling the patient

  • This antibiotic is given by injection or infusion under clinical supervision.
  • Report any rash, swelling, breathing difficulty, or severe or persistent diarrhoea.

Evidence & guidelines

Cefotaxime is established in UK and NICE guidance as a treatment option for serious infections including community-acquired bacterial meningitis.

Reference: UKHSA; NICE NG52; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Drugs
Pathways