What is the recommended dose of ceftriaxone (a cephalosporin antibiotic) for preoperative antibiotic prophylaxis?

Ceftriaxone Dose for Preoperative Prophylaxis

For most surgical procedures, administer ceftriaxone 1 gram intravenously as a single dose 30-120 minutes (ideally 30-60 minutes) before surgical incision. 1

Standard Adult Dosing

• The FDA-approved dose for surgical prophylaxis is 1 gram IV administered 0.5 to 2 hours before surgery 1
• This single preoperative dose provides adequate tissue concentrations throughout most surgical procedures and reduces postoperative infection rates significantly 2
• The Dutch Trauma Trial demonstrated that a single preoperative dose of ceftriaxone reduced infection rates from 8.3% to 3.6% (P < 0.001) in patients with closed fractures 2

Timing Considerations

• Administer the dose within 60 minutes before incision, with optimal timing at 30-60 minutes preoperatively 3, 1
• Complete the infusion before surgical incision to ensure adequate tissue levels at the time of contamination 3, 4
• For procedures using a tourniquet, complete the infusion before tourniquet inflation 2

Intraoperative Redosing

• Redose with 1 gram if the procedure exceeds 4-6 hours or if significant blood loss (>1.5 L) occurs 3, 1
• Redosing should occur when the procedure duration exceeds two half-lives of the antibiotic (ceftriaxone half-life is approximately 6.5 hours) 4, 5

Duration of Prophylaxis

• Limit prophylaxis to a maximum of 24 hours postoperatively, never extending beyond 48 hours 2, 3
• Single-dose prophylaxis is adequate for most procedures, and extending beyond 24 hours increases antibiotic resistance risk without improving outcomes 2, 3
• The presence of surgical drains does not justify extending prophylaxis beyond these timeframes 6, 4

Special Populations

Pediatric Patients

• For skin and skin structure infections or miscellaneous serious infections: 50-75 mg/kg once daily (maximum 2 grams) 1
• For meningitis: Initial dose of 100 mg/kg (maximum 4 grams), then 100 mg/kg/day (maximum 4 grams daily) 1
• For acute otitis media: Single IM dose of 50 mg/kg (maximum 1 gram) 1

Neonates

• Administer IV doses over 60 minutes in neonates to reduce the risk of bilirubin encephalopathy 1
• Ceftriaxone is contraindicated in premature neonates and in neonates ≤28 days requiring calcium-containing IV solutions 1

Obese Patients

• For patients weighing ≥120 kg, higher doses may be required, though specific ceftriaxone dosing is not well-defined in the evidence 3

Administration Protocol

• Administer as a slow IV infusion over 30 minutes for adults (60 minutes for neonates) 1
• Concentrations between 10-40 mg/mL are recommended for IV administration 1
• Do not use calcium-containing diluents (Ringer's solution, Hartmann's solution) as precipitation can occur 1

Critical Pitfalls to Avoid

• Do not administer the dose too early (>120 minutes before incision), as tissue levels may be inadequate at the time of surgical contamination 3
• Do not routinely extend prophylaxis beyond 24 hours postoperatively—this practice promotes antibiotic resistance without providing additional benefit 2, 3
• Do not forget to redose during prolonged procedures, as inadequate intraoperative levels increase infection risk 3, 4
• Do not mix with calcium-containing solutions, as ceftriaxone-calcium precipitation can occur 1

Alternative Considerations

• While ceftriaxone 1 gram is effective, cefazolin 1-2 grams IV is more commonly used for most surgical prophylaxis due to its narrower spectrum and lower cost 6, 3
• For penicillin-allergic patients, clindamycin 900 mg IV or vancomycin 30 mg/kg IV (over 120 minutes) are appropriate alternatives 6, 3, 4
• Ceftriaxone has no activity against Chlamydia trachomatis, so add appropriate antichlamydial coverage when this pathogen is suspected 1