Vancomycin

also known as: Vancocin

The iconic glycopeptide antibiotic — the gold-standard MRSA treatment for over 60 years, acting by binding D-Ala-D-Ala to block cell wall synthesis.

A branched tricyclic glycopeptide antibiotic that binds the D-Ala-D-Ala terminus of peptidoglycan precursors, sterically blocking transglycosylation and transpeptidation of the gram-positive bacterial cell wall.

Mechanism of action

Binds with high affinity to the D-Ala-D-Ala dipeptide terminus of lipid II (the peptidoglycan precursor), forming a non-covalent complex that sterically prevents both transglycosylation and transpeptidation. This blocks cell wall synthesis. VRE resistance arises from D-Ala-D-Lac substitution, which reduces binding affinity 1000-fold.

Primary uses

MRSA infections (IV)
Clostridioides difficile colitis (oral)
Prosthetic device infections
Surgical prophylaxis (beta-lactam allergy)

Typical dosing

15–20 mg/kg every 8–12 hours (IV); 125 mg 4x daily (oral for C. diff) (intravenous or oral)

IV for systemic infections. Oral vancomycin is not absorbed and acts locally in the gut for C. difficile.

Regulatory status

FDA-approved in 1958. Indicated for serious gram-positive infections including MRSA, C. difficile colitis (oral), and surgical prophylaxis in beta-lactam-allergic patients. Multiple generic formulations available.

References

[review] Rybak MJ, et al. "Therapeutic monitoring of vancomycin for serious methicillin-resistant Staphylococcus aureus infections." Clin Infect Dis, 2020;71:1361-1364.

Related peptides

Daptomycin

A last-resort lipopeptide antibiotic — the first-in-class cyclic peptide that kills MRSA and VRE by depolarizing bacterial membranes, without resistance through traditional mechanisms.

LL-37

The only human cathelicidin — an antimicrobial peptide with direct activity against bacteria, fungi, viruses, and biofilms, with additional roles in wound healing and immune signaling.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.