Vancomycin

Our patients are frequently on Vancomycin, due to the increasing incidence of ORSA in both hospital-acquired infections, and community-acquired infections. ORSA can cause a variety of infections, and we commonly follow patients with ORSA pneumonia, cellulitis, deep soft tissue infections, abscesses, osteomyelitis, bacteremia and endocarditis. Vancomycin does also cover other gram-positives, but is the treatment of choice for ORSA infections. It is the treatment of choice in PCN-allergic patients with gram positive infections. There are several important things to remember when treating a patient with Vancomycin:

1. Weight and renal function (measured by GFR or creatinine clearance). Both will influence the therapeutic dosing of Vancomycin. Generally, Vancomycin is dosed 15-20 mg/kg, and given q12h hours in patients with normal renal function.

2. Vancomycin is not absorbed systemically when given orally. Therefore, po Vancomycin is only approved as second-line treatment of C. difficile colitis. Otherwise, it should ALWAYS be given intravenously.

3. Weekly labs. When on Vancomycin, weekly labwork should be checked and should include: CBC with differential, BUN and creatinine, and Vancomycin trough.

4. Goal troughs. Vancomycin is monitored via the collection of troughs, which should be drawn ~30 minutes prior to the next scheduled dose. In general, peak testing is unnecessary. The goal trough will depend on the site of infection (keeping in mind that these goals have been extrapolated from other data, and have yet to be verified in clinical studies):

1. Goal trough of 15-20 mcg/ml is reserved for Pneumonia, Endocarditis, Meningitis, and Osteomyelitis.


2. Goal trough of 10-15 mcg/ml is used for skin and soft tissue infections and Bacteremia.

5. Adverse Reactions.

1. "Red Man Syndrome." A systemic response to the infusion, that includes flushing and sweating. Is not dangerous, and is not an allergy. It can usually be remedied by slowing the infusion rate, and/or diluting the Vancomycin in a larger volume of solute.


2. Ototoxicity. Generally not reversible, and occurs at high levels.


3. Renal failure. Uncommon, except when Vancomycin is given concomitantly with other nephrotoxic agents. If a patient develops ARF while on Vancomycin, you can generally continue Vancomycin, making dose adjustments, while the cause of the ARF is being worked up.

***In terms of when we follow Vancomycin levels, we should follow Vancomycin levels on patients on which we recommended the use of IV Vancomycin when seen as an inpatient AND will follow up with you in ID Clinic. In cases where we do not plan to see the patient in follow up, the team should make arrangements for that patient's outpatient provider to follow labwork. You may volunteer to follow labwork on these patients if they have no provider to do so. BUT, you should NEVER follow Vancomycin levels or labs on patients whom you have not seen. We have been called to follow labs on patients being discharged from various services who are going home or to a SNIF on Vancomycin. The answer to this request should be a firm NO. It becomes a legal liability when following labwork on a patient you don't know and have never seen, and in whom you did not recommend Vancomycin in the first place. What if they develop an adverse drug reaction??? Who is responsible? On paper, you would be, as the ordering physician. So, keep that in mind. Most services have no staff in place assigned to follow labwork on patients on IV antibiotics, and remember, NEITHER DO WE. It is our responsibility as fellows to follow it on our patients only. We should not volunteer to do it as a service for the entire hospital. Just imagine how many labs we would be following if we monitored labs on every patient discharged on Vancomycin from UNC?!?! Please make requesting services aware of this.***

Yvonne Carter, MD