Skip to main content
PharmSpace

Cephalosporins · Anti-infectives

Ceftriaxone

Rocephin®(brand names vary by market)

Once a day, into the CSF, and hard on the gut flora.

Illustration of Ceftriaxone as a injection

Also: infusion

Mechanism

Third-generation cephalosporin with extended Gram-negative coverage and enough CNS penetration to treat meningitis.

Indications

  • Community-acquired pneumonia
  • Pyelonephritis
  • Meningitis
  • Gonorrhoea
  • Spontaneous bacterial peritonitis
  • Septic arthritis

Formulations

InjectionInfusion

Dosing concepts

Once daily

Its long half-life allows once-daily dosing, which is what makes outpatient parenteral therapy practical.

Meningitis doses

CNS infection needs substantially higher doses than pneumonia, because penetration across an inflamed but still selective barrier is incomplete.

Renal impairment

Largely biliary, so it is one of the few antibiotics needing little renal adjustment.

Concepts, not prescribing instructions. Practice numbers live in current references and local protocols.

Pharmacokinetics

Bioavailability
Parenteral only
Half-life
6 to 9 h
Elimination
mixed: Substantial biliary excretion, which is why renal dosing is rarely needed
Protein binding
~95%
Play with these concepts in the PK Lab

Adverse effects

  • Diarrhoea and C. difficilecommon & seriousBroad Gram-negative coverage means substantial collateral damage to gut flora.
  • Rashcommon
  • Biliary pseudolithiasisseriousPrecipitates in bile as calcium salts; usually asymptomatic and reversible.
  • Hemolytic anemiaseriousRare and immune-mediated.

Contraindications & precautions

Contraindications

  • Prior severe cephalosporin hypersensitivity
  • Neonates receiving calcium-containing intravenous fluids
  • Neonatal hyperbilirubinemia

Precautions

  • Prior C. difficile
  • Concurrent calcium-containing infusions through the same line

Interactions

Monitoring

Clinical response and de-escalation opportunity

Broad therapy should narrow once cultures return; that is the whole of stewardship in one habit

Diarrhoea

C. difficile risk is meaningful with this agent

Counselling points

  • Given by injection, usually once daily.
  • Report diarrhoea, especially if severe or bloody.
  • Tell us about any previous reaction to penicillins or cephalosporins.

Clinical pearls

  • It covers neither enterococci nor Pseudomonas. A patient failing on ceftriaxone frequently has one of those two.
  • Because it needs little renal adjustment and is given once daily, it is the backbone of outpatient intravenous antibiotic programmes.

References & review

  • Ceftriaxone product monograph (consult the current version for your market) (monograph)
  • Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed. (reference-work)

Last reviewed 2026-08-16 · jurisdiction: global · drug information changes; verify against current references before practice use.