What antibiotic is commonly given before and after surgery to prevent infection?

• A. Vancomycin
• B. Ancef
• C. Amoxicillin
• D. Metronidazole

Answer: (B)

Perioperative antibiotic prophylaxis is used to ensure the wound is bathed in effective levels of antibiotic exactly when the incision is made, reducing the risk of surgical site infections. Ancef, which is cefazolin, is the most commonly used agent for this purpose because it provides strong coverage against the skin flora most often causing post-op infections, particularly Staphylococcus aureus and Streptococcus species, and has reliable tissue penetration. The best practice is to administer it IV within about 60 minutes before the incision so therapeutic levels are present during the operation; if the surgery is prolonged or there is significant blood loss, the dose may be repeated to maintain adequate levels. Postoperative antibiotics are not routinely needed for most clean surgeries, though a post-op dose may be used in specific situations. Vancomycin is reserved for penicillin-allergic patients or MRSA risk, while amoxicillin and metronidazole are not the standard universal perioperative prophylaxis in this context.