Vancomycin

Vancomycin (Vancocin) is a glycopeptide antibiotic primarily used to treat methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile (“C.diff”) colitis with the intravenous and oral forms, respectively. In general, it’s used for “gram positive coverage” (Enterococcus, Staph, etc.). Remember that vancomycin is NOT appropriate therapy for methicillin SENSITIVE Staph (consider oxacillin or nafcillin). Oral vancomycin is retained in the GI tract (vancomycin is a large molecule that doesn’t significantly cross the intestinal barrier), so dosing considerations are different than the traditional intravenous route.

As a cardiac anesthesiologist, I most often use vancomycin in combination with a cephalosporin (typically cefazolin) to provide perioperative prophylaxis against surgical site infections due to a high prevalence of MRSA at the institutions I’ve trained at. As an intensivist, I use vancomycin in combination with other powerful antibiotics (pipercillin-tazobactam, cefepime, meropenem, etc.) to provide broad coverage in patients who are decompensating (ie, sepsis with inadequate source control), have MRSA pneumonia, have a suspicion for MRSA endocarditis, etc. Once sensitivities have come back, I’ll always try to narrow the antibiotic choice. My infectious disease colleagues are incredibly helpful whenever I have questions!

“Vancomycin infusion reaction” is an infusion rate dependent, histamine-mediated reaction manifested by facial/truncal erythema. While this isn’t a “true” allergy, the rate of infusion should still be slowed! Additionally, vancomycin is primarily eliminated via tubular secretion and glomerular filtration in the kidneys and may confer some degree of damage via oxidative effects and alteration of tubular epithelium. It’s important to check vancomycin troughs (usually before the 4th dose) and overall renal function to adjust doses in the course of therapy.

Drop me a comment below with questions! 🙂