Understanding the uses: What is the drug vancomycin used for?

October 7, 2025 •

3 min read

Originally derived from a soil fungus in the 1950s, vancomycin is a powerful glycopeptide antibiotic that has become a cornerstone of modern infectious disease treatment. Today, it is primarily used to treat severe, drug-resistant bacterial infections, a role that has made the question 'What is the drug vancomycin used for?' highly relevant in clinical practice.

Quick Summary

Vancomycin is a potent glycopeptide antibiotic used to combat serious and often drug-resistant bacterial infections, including MRSA and severe C. difficile colitis, with its administration route dictated by the type of infection.

Key Points

Targeting Gram-Positive Bacteria: Vancomycin is a glycopeptide antibiotic that primarily kills Gram-positive bacteria by disrupting their cell wall synthesis.
IV for Systemic Infections: Intravenous vancomycin is used for serious systemic infections like MRSA bacteremia, endocarditis, meningitis, and sepsis.
Oral for Intestinal Infections: Oral vancomycin is specifically for intestinal infections such as severe Clostridioides difficile colitis, as it is poorly absorbed into the bloodstream.
Requires Close Monitoring: Due to its narrow therapeutic window and potential for kidney damage (nephrotoxicity), intravenous vancomycin therapy requires careful therapeutic drug monitoring (TDM) of serum levels.
Potential for Side Effects: Common side effects include Vancomycin Flushing Syndrome (Red Man Syndrome), and there's a risk of more serious effects like nephrotoxicity and ototoxicity.
Importance of Careful Use: The rise of vancomycin-resistant enterococci (VRE) and other resistance issues necessitates judicious use of vancomycin to preserve its effectiveness.

Vancomycin's Mechanism of Action: The Cell Wall Inhibitor

Vancomycin is a bactericidal antibiotic that works by disrupting the synthesis of the bacterial cell wall. Specifically, it targets Gram-positive bacteria, which have a thick cell wall exposed to the external environment, and binds to the D-alanyl-D-alanine portion of the cell wall's precursor units. By binding to this site, it prevents the cross-linking and elongation of the peptidoglycan chains, which are essential for a strong and stable cell wall. This causes the bacteria to become vulnerable to osmotic pressure, leading to cell lysis and death. Its large molecular size prevents it from penetrating the outer membrane of Gram-negative bacteria, which is why it is ineffective against them.

The Primary Uses of Vancomycin

Vancomycin's use is reserved for serious infections caused by susceptible Gram-positive bacteria, especially when other, less toxic antibiotics have failed or are unsuitable. The route of administration—oral or intravenous—depends entirely on the location of the infection due to the drug's poor systemic absorption when taken by mouth.

Intravenous Vancomycin for Systemic Infections

For infections throughout the body, vancomycin is administered intravenously (IV). Its major systemic indications include:

Methicillin-Resistant Staphylococcus Aureus (MRSA): Vancomycin is the standard treatment for severe MRSA infections, such as bacteremia, infective endocarditis, and pneumonia.
Septicemia/Sepsis: Used to treat septicemia, a serious bloodstream infection that can lead to sepsis, especially when caused by Gram-positive pathogens.
Infective Endocarditis: Treats infections of the inner lining of the heart and valves caused by susceptible bacteria like MRSA, streptococci, and enterococci.
Meningitis: For patients with bacterial meningitis caused by penicillin-resistant Streptococcus pneumoniae or other susceptible Gram-positive bacteria, often used in combination with a third-generation cephalosporin.
Bone and Joint Infections (Osteomyelitis): Treats serious bone infections caused by susceptible organisms.
Skin and Soft Tissue Infections: Used for complicated skin infections, especially those caused by MRSA.

Oral Vancomycin for Intestinal Infections

When taken orally, vancomycin is poorly absorbed into the bloodstream, meaning it exerts its antibiotic effect directly within the gastrointestinal (GI) tract. This makes it the drug of choice for treating:

Clostridioides difficile-associated diarrhea (CDAD): Used for severe cases of C. difficile colitis, a serious infection of the colon, and in cases of recurrence.
Staphylococcal enterocolitis: Treats intestinal inflammation caused by Staphylococcus aureus.

Therapeutic Drug Monitoring and Adverse Effects

Given the narrow therapeutic window between efficacy and toxicity, intravenous vancomycin requires careful monitoring, particularly in patients with pre-existing kidney conditions. Clinicians regularly measure serum vancomycin concentrations, specifically the trough level, to ensure the dose is both effective and safe.

Nephrotoxicity (Kidney Damage): This is a well-known risk, especially with high doses, prolonged therapy, or concurrent use of other nephrotoxic drugs.
Ototoxicity (Hearing Damage): Though rarer with modern, purer formulations, it can still occur, causing tinnitus or hearing loss.
Vancomycin Flushing Syndrome (formerly Red Man Syndrome): An infusion-related reaction that can cause flushing, rash, and itching, particularly on the face, neck, and torso. It is typically mitigated by administering the drug slowly.

Comparison of Vancomycin Administration Routes


Feature	Intravenous (IV) Administration	Oral Administration
Infections Treated	Systemic, serious infections such as bacteremia, endocarditis, and MRSA infections in various body tissues.	Intestinal infections only, such as C. difficile colitis and staphylococcal enterocolitis.
Bioavailability	100% absorption into the bloodstream for systemic effect.	Poorly absorbed; acts locally within the gastrointestinal tract.
Dosing	Personalized based on patient weight, kidney function, and serum drug levels; typically administered multiple times daily.	Standard doses, usually 125 mg to 500 mg, taken several times a day for a specified duration.
Monitoring	Routine therapeutic drug monitoring (TDM) is essential due to risk of nephrotoxicity and ototoxicity.	Serum level monitoring is generally not required due to minimal systemic absorption.

Conclusion

Vancomycin remains an indispensable antibiotic for treating serious and resistant Gram-positive bacterial infections, including those caused by MRSA and C. difficile. The correct administration route, whether intravenous for systemic infections or oral for intestinal ones, is critical to its effectiveness. However, its use is carefully managed due to potential side effects like nephrotoxicity and the risk of developing resistance in pathogens like vancomycin-resistant enterococci (VRE). Careful therapeutic drug monitoring and an interprofessional approach are necessary to optimize its use and preserve its effectiveness for when it is truly needed. As bacteria continue to evolve, understanding vancomycin's specific applications and limitations is crucial for effective patient care and infection control.

Learn more about vancomycin from the National Institutes of Health(https://clinicalinfo.hiv.gov/en/drugs/vancomycin-hydrochloride/patient).

Frequently Asked Questions

Vancomycin is used to treat serious bacterial infections, especially those caused by Gram-positive bacteria that are resistant to other antibiotics. Examples include methicillin-resistant Staphylococcus aureus (MRSA) infections, septicemia, endocarditis, and severe C. difficile colitis.

The route of administration depends on the infection's location. For systemic infections like sepsis, vancomycin is given intravenously (IV) to enter the bloodstream. For intestinal infections like C. difficile, it is given orally because it is poorly absorbed and can act directly in the gut.

IV vancomycin is used for infections throughout the body, as it enters the bloodstream effectively. Oral vancomycin is for intestinal infections only, as it stays primarily in the digestive tract.

Vancomycin Flushing Syndrome, also known as Red Man Syndrome, is a reaction that can occur if vancomycin is infused too quickly. It causes flushing, a rash, and itching on the upper body and neck due to histamine release, and is often avoided by slowing the infusion rate.

For IV treatment, doctors monitor vancomycin levels in the blood, typically by measuring the 'trough' level (the lowest concentration before the next dose). This ensures the medication is effective and helps prevent toxicity, particularly kidney damage.

Yes, nephrotoxicity (kidney damage) is a potential side effect of intravenous vancomycin. The risk is higher with higher doses, prolonged use, or in patients who are older or have pre-existing kidney disease.

No. Vancomycin is only effective against Gram-positive bacteria, such as staphylococci and streptococci. It is not effective against Gram-negative bacteria because its large size prevents it from crossing their protective outer cell membrane.