Should I add Vancomycin (Vanco) to the treatment regimen?

Should You Add Vancomycin?

Without knowing the specific clinical context, I cannot definitively recommend adding vancomycin, but if you are treating a febrile patient with gram-positive cocci on blood cultures, suspected MRSA infection, severe staphylococcal infection, or fulminant Clostridioides difficile infection, then yes—add vancomycin immediately. 1, 2

When Vancomycin Should Be Added

Gram-Positive Coverage in Febrile Patients

• Add vancomycin empirically if gram-positive cocci are identified on blood cultures until final identification and susceptibility testing is available 1
• Add vancomycin if the patient is colonized with MRSA or your institution has high rates of MRSA infections 1
• Add vancomycin for high-risk febrile neutropenic patients with hemodynamic instability, severe sepsis, radiographically documented pneumonia, or catheter-related infections 3

Specific Infections Requiring Vancomycin

MRSA Infections:

• Vancomycin is indicated for serious or severe infections caused by methicillin-resistant staphylococci 4
• For complicated skin and soft tissue infections requiring hospitalization, use vancomycin 30-60 mg/kg/day IV in 2-4 divided doses 2
• For MRSA bacteremia (both complicated and uncomplicated), vancomycin 30-60 mg/kg/day IV is the treatment of choice 2

Staphylococcal Endocarditis:

• For native valve endocarditis caused by MRSA, use vancomycin 30-60 mg/kg/day IV for 4-6 weeks 2
• For prosthetic valve endocarditis, combine vancomycin with rifampin and gentamicin for 6 weeks 2

Fulminant Clostridioides difficile Infection:

• For fulminant CDI with hypotension, shock, ileus, or megacolon, use vancomycin 500 mg orally 4 times daily 2
• Add intravenous metronidazole 500 mg every 8 hours together with oral vancomycin, particularly if ileus is present 2
• Consider rectal vancomycin 500 mg in 100 mL normal saline every 6 hours if ileus prevents oral administration 2

Enterococcal Infections:

• For enterococcal endocarditis in penicillin-allergic patients, use vancomycin combined with gentamicin for 6 weeks 2
• For suspected Enterococcus faecium bacteremia, vancomycin should be used empirically 1

When Vancomycin Should NOT Be Added

Persistent Fever Alone:

• Do not add vancomycin empirically for persistent or recrudescent fever in an otherwise stable, asymptomatic patient 2
• A randomized study showed no difference in time-to-defervescence when vancomycin was added to piperacillin-tazobactam after 60-72 hours of persistent fever 2

Negative Cultures:

• Stop vancomycin if blood cultures have incubated for 48 hours and show no pathogenic gram-positive organisms 2
• Avoid unnecessary vancomycin continuation when cultures are negative for β-lactam-resistant gram-positive organisms 1

Single Positive Culture for Coagulase-Negative Staphylococci:

• Do not use vancomycin for a single blood culture positive for coagulase-negative staphylococci if a second set is negative—this is likely a contaminant 1

Non-Severe CDI:

• For initial episodes of non-severe C. difficile infection, vancomycin 125 mg orally 4 times daily OR fidaxomicin is preferred over metronidazole, but vancomycin is not added to other antibiotics 2

Dosing Considerations

Standard Dosing:

• For most serious infections: vancomycin 15 mg/kg/dose IV every 6-12 hours (30-60 mg/kg/day total) 2
• Loading dose of 25-30 mg/kg may be appropriate in critically ill patients 2
• For MRSA pneumonia in critically ill trauma patients with normal renal function, doses of at least 1 g IV every 8 hours are needed to achieve therapeutic trough concentrations of 15-20 mg/L 5

Oral Dosing (CDI only):

• Non-severe CDI: 125 mg orally 4 times daily for 10 days 2
• Fulminant CDI: 500 mg orally 4 times daily 2

Critical Pitfalls to Avoid

• Do not delay vancomycin in a febrile patient with gram-positive cocci on blood culture—this can increase mortality with virulent organisms 1
• Monitor renal function closely when vancomycin is used with other nephrotoxic drugs like aminoglycosides, amphotericin B, or cisplatin 4
• Avoid rapid IV infusion to prevent "red man syndrome" characterized by erythema, flushing, and potential hypotension 6, 7
• Adjust dosing in elderly patients and those with renal insufficiency as vancomycin clearance is reduced and elimination half-life is prolonged 4, 7
• De-escalate from vancomycin to appropriate β-lactam therapy when culture results show susceptible organisms 1