Procedure		Likely organisms	Recommended antibiotic*	Adult dose†
Cutaneous		Staphylococcus aureus, Staphylococcus epidermidis‡	No uniform recommendation§
Head and neck		S. aureus, streptococci	Cefazolin (Ancef, Kefzol)	1 to 2 g intravenously
Neurosurgery		S. aureus, S. epidermidis	Cefazolin	1 to 2 g intravenously
Thoracic		S. aureus, S. epidermidis	Cefazolin	1 to 2 g intravenously
Cardiac		S. aureus, S. epidermidis	Cefazolin∥	1 to 2 g intravenously
Abdominal
	Gastroduodenal	Gram-positive cocci, enteric gram-negative bacilli	High risk: cefazolin	1 to 2 g intravenously
	Colorectal¶	Enteric gram-negative bacilli, anaerobes	Oral: neomycin (Neosporin) and erythromycin base	1 g orally (3 doses)#
			Parenteral: cefotetan (Cefotan) or cefoxitin (Mefoxin)	1 to 2 g intravenously
	Appendectomy	Enteric gram-negative bacilli, anaerobes	Cefotetan or cefoxitin	1 to 2 g intravenously
	Biliary	Enteric gram-negative bacilli	High risk: cefazolin	1 to 2 g intravenously
Gynecologic and obstetric		Enteric gram-negative bacilli, group B streptococcus, anaerobes	Cefazolin**	1 to 2 g intravenously
Urologic		S. aureus, enteric gram-negative bacilli	Cefazolin††	1 to 2 g intravenously
Orthopedic		S. aureus, S. epidermidis	Cefazolin	1 to 2 g intravenously
Noncardiac vascular		S. aureus, S. epidermidis, enteric gram-negative bacilli	Cefazolin	1 to 2 g intravenously
Breast and hernia		S. aureus, S. epidermidis	High risk: cefazolin‡‡	1 to 2 g intravenously