ADULTS
For most surgical procedures, joint clinical practice guidelines from the American Society of Health-System Pharmacists, Infectious Diseases Society of America, Surgical Infection Society, and Society for Healthcare Epidemiology of America (ASHP/IDSA/SIS/SHEA) recommend a dose of 2g within 60 minutes prior to surgical incision (for non-obese patients weighing <120 kg).
OBESE ADULTS
The ASHP/IDSA/SIS/SHEA guidelines recommend that for patients weighing ≥120 kg, a dose of 3g within 60 minutes prior to surgical incision should be administered (Bratzler 2013). Alternatively, for patients with BMI >40 kg/m2, a single 2g dose may be sufficient for common general surgical procedures lasting <5 hours; patients enrolled in this multigroup study had a BMI up to a group mean of 55.7 kg/m2 (Ho 2012).
PEDIATRIC
Perioperative prophylaxis (off-label use):Children ≥1 year: IV: For most surgical procedures, joint clinical practice guidelines from the American Society of Health-System Pharmacists, Infectious Diseases Society of America, Surgical Infection Society, and Society for Healthcare Epidemiology of America (ASHP/IDSA/SIS/SHEA) recommend a dose of 30 mg/kg (maximum dose: 2,000 mg) administered within 60 minutes prior to surgical incision. For procedures requiring anaerobic coverage (eg, appendectomy, small bowel surgery with intestinal obstruction, colon procedures), combine cefazolin with metronidazole as an alternative to a second generation cephalosporin with anaerobic activity (eg, cefoxitin or cefotetan). Cefazolin doses may be repeated intraoperatively in 4 hours if procedure is lengthy or if there is excessive blood loss (Bratzler 2013).
NOTE: Cefazolin doses may be repeated intraoperatively in 4 hours if procedure is lengthy or if there is excessive blood loss (Bratzler 2013). For clean and clean-contaminated procedures, continued prophylactic antibiotics beyond surgical incision closure is not recommended, even in the presence of a drain (CDC [Berríos-Torres 2017]).