Table 1

Recommended Doses and Redosing Intervals for Commonly Used Antimicrobials for Surgical Prophylaxis

AntimicrobialRecommended DoseHalf-life in Adults With Normal Renal Function, hr19Recommended Redosing Interval (From Initiation of Preoperative Dose), hrc
AdultsaPediatricsb
Ampicillin-sulbactam3g (ampicillin 2g/sulbactam 1 g)50 mg/kg of the ampicillin component0.8–1.32
Ampicillin2g50 mg/kg1–1.92
Aztreonam2g30 mg/kg1.3–2.44
Cefazolin2 g, 3 g for pts weighing ≥120 kg30 mg/kg1.2–2.24
Cefuroxime1.5g50 mg/kg1–24
Cefotaxime1 gd50 mg/kg0.9–1.73
Cefoxitin2 g40 mg/kg0.7–1.12
Cefotetan2 g40 mg/kg2.8–4.66
Ceftriaxone2 ge50–75 mg/kg5.4–10.9NA
Ciprofloxacinf400 mg10 mg/kg3–7NA
Clindamycin900 mg10 mg/kg2–46
Ertapenem1 g15 mg/kg3–5NA
Fluconazole400 mg6 mg/kg30NA
Gentamicing5 mg/kg based on dosing weight (single dose)2.5 mg/kg based on dosing weight2–3NA
Levofloxacinf500 mg10 mg/kg6–8NA
Metronidazole500 mg15 mg/kg Neonates weighing <1200 g should receive a single 7.5-mg/kg dose6–8NA
Moxifloxacinf400 mg10 mg/kg8–15NA
Piperacillin-tazobactam3.375 gInfants 2–9 mo: 80 mg/kg of the piperacillin component Children >9 mo and ≤40 kg: 100 mg/kg of the piperacillin component0.7–1.22
Vancomycin15 mg/kg15 mg/kg4–8NA
Oral antibiotics for colorectal surgery prophylaxis (used in conjunction with a mechanical bowel preparation)
Erythromycin base1 g20 mg/kg0.8–3NA
Metronidazole1 g15 mg/kg6–10NA
Neomycin1 g15 mg/kg2–3 (3% absorbed under normal gastrointestinal conditions)NA
  • a Adult doses are obtained from the studies cited in each section. When doses differed between studies, expert opinion used the most-often recommended dose.

  • b The maximum pediatric dose should not exceed the usual adult dose.

  • c For antimicrobials with a short half-life (e.g., cefazolin, cefoxitin) used before long procedures, redosing in the operating room is recommended at an interval of approximately two times the half-life of the agent in patients with normal renal function. Recommended redosing intervals marked as "not applicable" (NA) are based on typical case length; for unusually long procedures, redosing may be needed.

  • d Although FDA-approved package insert labeling indicates 1 g,14 experts recommend 2 g for obese patients.

  • e When used as a single dose in combination with metronidazole for colorectal procedures.

  • f While fluoroquinolones have been associated with an increased risk of tendinitis/tendon rupture in all ages, use of these agents for single-dose prophylaxis is generally safe.

  • g ln general, gentamicin for surgical antibiotic prophylaxis should be limited to a single dose given preoperatively. Dosing is based on the patient’s actual body weight. If the patient’s actual weight is more than 20% above ideal body weight (IBW), the dosing weight (DW) can be determined as follows: DW = IBW + 0.4(actual weight - IBW).