What coverage does IV (intravenous) vancomycin provide?

From the Guidelines

Intravenous vancomycin provides broad coverage against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus aureus (MSSA), coagulase-negative staphylococci, enterococci, and streptococci, making it a crucial option for treating complicated skin and soft tissue infections (cSSTI) and other severe infections 1.

Key Coverage and Usage

• IV vancomycin is effective against MRSA, MSSA, coagulase-negative staphylococci, enterococci, and streptococci, including Streptococcus pneumoniae 1.
• It is also used to treat Clostridium difficile infections, although oral vancomycin is preferred for this indication 1.
• The typical dosing for adults is 15-20 mg/kg every 8-12 hours, with adjustments based on renal function and therapeutic drug monitoring 1.
• Target trough levels are usually 10-15 μg/mL for most infections and 15-20 μg/mL for severe infections like endocarditis 1.

Mechanism of Action and Limitations

• Vancomycin works by inhibiting cell wall synthesis in bacteria by binding to D-alanyl-D-alanine components of the cell wall, preventing cross-linking and weakening bacterial cell walls 1.
• It has poor coverage against gram-negative bacteria due to its large molecular size preventing penetration through the outer membrane 1.
• Vancomycin does not effectively treat anaerobes other than C. difficile 1.

Clinical Guidelines and Recommendations

• For hospitalized patients with complicated SSTI, empirical therapy for MRSA should be considered pending culture data, with IV vancomycin being a recommended option 1.
• The Infectious Diseases Society of America guidelines support the use of vancomycin for the treatment of MRSA infections, including cSSTI 1.

From the FDA Drug Label

Vancomycin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section. Aerobic gram-positive microorganisms Diphtheroids Enterococci (e. g., Enterococcus faecalis) Staphylococci, including Staphylococcus aureus and Staphylococcus epidermidis (including heterogeneous methicillin-resistant strains) Streptococcus bovis Viridans group streptococci The following in vitro data are available, but their clinical significance is unknown Vancomycin exhibits in vitro MIC's of 1 mcg/mL or less against most (≥90%) strains of streptococci listed below and MIC's of 4 mcg/mL or less against most (≥90%) strains of other listed microorganisms; however, the safety and effectiveness of vancomycin in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled clinical trials Aerobic gram-positive microorganisms Listeria monocytogenes Streptococcus pyogenes Streptococcus pneumoniae (including penicillin-resistant strains) Streptococcus agalactiae Anaerobic gram-positive microorganisms Actinomyces species Lactobacillus species

IV vancomycin provides coverage against aerobic gram-positive microorganisms, including:

• Staphylococci (e.g., Staphylococcus aureus, Staphylococcus epidermidis)
• Enterococci (e.g., Enterococcus faecalis)
• Streptococci (e.g., Streptococcus bovis, Viridans group streptococci)
• Diphtheroids And also against some anaerobic gram-positive microorganisms, including:
• Actinomyces species
• Lactobacillus species Additionally, vancomycin exhibits in vitro activity against other microorganisms, such as Listeria monocytogenes, Streptococcus pyogenes, Streptococcus pneumoniae (including penicillin-resistant strains), and Streptococcus agalactiae 2.

From the Research

Coverage of IV Vancomycin

IV vancomycin provides coverage against a range of gram-positive bacteria, including:

• Staphylococcal infections, particularly methicillin-resistant Staphylococcus aureus (MRSA) 3, 4, 5
• Streptococcal infections, including Streptococcus bovis and viridans streptococcal endocarditis 3
• Enterococcal infections, although it is often used in combination with an aminoglycoside 3, 6
• Corynebacterial endocarditis 3

Spectrum of Activity

The antibacterial spectrum of vancomycin also covers other gram-positive cocci and bacteria, as well as some gram-negative cocci 3. However, it is not effective against most gram-negative bacteria, such as Pseudomonas aeruginosa 7.

Usage and Dosage

IV vancomycin is typically administered in a dose of 1 g every 12 hours in patients with normal renal function 3. However, some studies suggest that higher doses, such as 1 g every 8 hours, may be needed to achieve adequate trough concentrations in certain patient populations, such as critically ill trauma patients with MRSA pneumonia 4.