Antibiotic prophylaxis is indicated only under specific surgical settings. Appropriate antibiotic prophylaxis must take into account the type of surgery, the competence of the host, and the pharmacologic properties of the antibiotic(s). The antibiotic should be given before the surgical procedure and have an antibacterial spectrum that covers the majority of the bacterial organisms anticipated at surgery. If there is doubt about the efficacy, antibiotic prophylaxis should not be initiated.