What is the recommended timing for prophylactic antibiotic administration relative to incision?

• A. Within 60 minutes before incision
• B. After wound closure
• C. 24 hours after incision
• D. Only if there is contamination

Answer: (A)

Giving prophylactic antibiotics within an hour before the incision ensures the drug reaches effective tissue concentrations precisely when the wound is opened. This timing protects the surgical site during the critical moment of incision and early dissection, reducing the risk of contamination turning into infection. If antibiotics are given after the incision or after wound closure, the wound has already been exposed and the protective levels may not be present when bacteria are most likely to enter, so the benefit is lost. Prophylaxis is intended to prevent infection in the surgical field, not to respond only after contamination occurs. In practice, some antibiotics with longer infusion times may be started a bit earlier (for example, up to about two hours before incision) to ensure adequate levels, and intraoperative redosing may be needed for lengthy procedures to maintain coverage.