ceftriaxone

Brand: Rocephin

Prototype Drug
Drug Class: antibiotic
Drug Family: antibiotic
Subclass: third-generation cephalosporin / beta-lactam
Organ Systems: infectious-disease

Mechanism of Action

Third-generation cephalosporin with expanded gram-negative coverage including Neisseria meningitidis, N. gonorrhoeae, Haemophilus influenzae, and most Enterobacteriaceae; poor anti-MRSA and anti-enterococcal activity; penetrates CSF well.

penicillin-binding proteins (PBPs)

Indications

  • community-acquired pneumonia (hospitalized patients)
  • bacterial meningitis
  • gonorrhea (drug of choice — IM)
  • Lyme disease (disseminated/severe)
  • typhoid fever
  • pelvic inflammatory disease
  • spontaneous bacterial peritonitis prophylaxis/treatment
  • sepsis (empiric)

Contraindications

  • neonates with hyperbilirubinemia (displaces bilirubin from albumin)
  • concurrent IV calcium in neonates (precipitation in lungs/kidneys)

Adverse Effects

Common

  • diarrhea
  • rash
  • elevated LFTs
  • biliary sludge (pseudolithiasis — especially with high doses/prolonged use)

Serious

  • anaphylaxis
  • C. difficile colitis
  • hemolytic anemia (Coombs-positive)
  • biliary sludge/cholelithiasis
  • calcium-ceftriaxone precipitates in neonates

Pharmacokinetics (ADME)

Absorption IV or IM only
Distribution Highly protein-bound (~93–96%); Vd ~0.12 L/kg; excellent CSF penetration in meningitis
Metabolism Not significantly metabolized
Excretion Dual — renal (~33–65%) and biliary (~35–45%); dose adjustment NOT typically required in renal failure (unlike most cephalosporins)
Half-life 5–9 hours — allows once-daily dosing
Onset End of infusion
Peak End of infusion
Duration 24 hours
Protein Binding 93–96%
Vd ~0.12 L/kg

Drug Interactions

Drug / Agent Mechanism Severity
calcium-containing IV fluids (neonates) calcium-ceftriaxone precipitation in lungs and kidneys — potentially fatal in neonates major
warfarin may prolong prothrombin time; monitor INR moderate

Nursing Considerations

  1. Reconstitute with appropriate diluent — do NOT use calcium-containing solutions (including Ringer's lactate) in neonates; may use in adults if infused at separate times
  2. Once-daily dosing (1–2 g q24h) is appropriate for most indications; bacterial meningitis requires 2 g q12h for adequate CSF concentrations
  3. Monitor for biliary sludge with prolonged use (>7–14 days) — present as RUQ pain; usually resolves after discontinuation
  4. For gonorrhea: current CDC guidelines recommend ceftriaxone 500 mg IM single dose (1 g if weight >150 kg) — azithromycin is no longer routinely added due to GC resistance

Clinical Pearls

  • Ceftriaxone's unique dual hepatic-renal elimination means it does NOT require dose adjustment in renal failure alone — a key prescribing advantage over most beta-lactams
  • Ceftriaxone remains first-line for bacterial meningitis (with dexamethasone) because of its excellent CSF penetration, once-daily dosing, and broad gram-negative coverage including N. meningitidis and H. influenzae

Safety Profile

Pregnancy generally-safe
Lactation safe
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required