Vancomycin: Uses, Side Effects, and Dosage

Vancomycin is an antibiotic of last resort usually used to treat drug-resistant infections. Vancomycin, a generic drug, was first isolated from Bornean soil samples more than 50 years ago. Initially, few clinicians used vancomycin, instead preferring other antibiotics that were considered more effective (vancomycin takes longer to act than penicillins) and less toxic.

However, beginning in the early 1980s, physicians and other healthcare professionals started to express renewed interest in this drug. This renewed interest was due both to vancomycin's ability to fight methicillin-resistant Staphylococcus aureus (MRSA) and the ability to treat pseudomembranous colitis. Pseudomembranous colitis is a severe infection of the colon (diarrhea) that takes hold after treatment with other antibiotics kills normal bowel flora. 

Mechanism of Action

Vancomycin is a tricyclic glycopeptide. It binds to bacterial cell walls and alters cell membrane permeability. It also interferes with bacterial RNA synthesis.

When fighting most gram-positive organisms like staphylococci and streptococci, vancomycin's actions are bacteriocidal. In other words, vancomycin works to directly kill the gram-positive bacteria. However, when fighting enterococci, another type of gram-positive organism, vancomycin's actions are bacteriostatic, and it works to inhibit bacterial reproduction.

What Is Vancomycin Used For?

As an antibiotic, Vancomycin treats bacterial infections. It targets a number of specific bacterial pathogens and can effectively cure a range of bacterial-related diseases.

Bacteria Covered

Vancomycin is active against various bacterial pathogens, many of which are resistant to other types of antibiotics, including:

• Severe staphylococcal infections in people who are allergic to penicillin: Affect skin and bloodstream
• MRSA: Affects skin and bloodstream
• Methicillin-resistant Staphylococcus epidermidis (MRSE): Affects skin, implanted medical devices, bloodstream
• Drug-resistant Streptococcus pneumoniae: Affects lungs, ears, meninges (brain lining)
• Severe enterococcal infections in people who are allergic to penicillin: Affect skin, heart valves, bloodstream)
• Severe enterococcal infections that are resistant to penicillin
• Viridans streptococci: Affects bloodstream and heart valves
• Multidrug-resistant Corynebacterium jeikeium: Affects bloodstream and heart valves
• Clostridium difficile (C. difficile or C. diff): Affects the gastrointestinal (GI) tract

Diseases Treated

Vancomycin is used to treat several forms of serious infection, including:

• Pneumonia
• Bone, skin, and soft-tissue infections
• Peritonitis (inflammation of the peritonium, within the abdominal wall)
• Endocarditis (heart infection)
• Enterocolitis and pseudomembranous colitis (bowel infections)
• To prevent disease when undergoing dental, biliary (upper abdomen), GI, respiratory, and genitourinary (in the genitals and urinary organs) infections
• Brain abscess (off-label use)
• Infections at the time of surgery (off-label use)
• Meningitis (off-label use)

Administration and Dosage

Because vancomycin is poorly absorbed by the gastrointestinal tract, it is usually administered as an injection. However, when used to treat enterocolitis and pseudomembranous colitis, both infections of the gastrointestinal tract, patients take oral vancomycin.

Vancomycin is usually administered in an inpatient (hospital) setting. Inpatient pharmacists are usually called on to calculate dosages. Furthermore, because vancomycin is excreted by the kidneys, the dosing of this drug is more complicated in people with renal failure (kidney failure).

Adverse Effects

Serious detrimental side effects attributable to vancomycin are rare. Vancomycin's most common adverse effect is a limited hypersensitivity or allergic reaction, as well as fever, nausea, rash, and tinnitus (ringing or rushing sound in ears). In rare yet serious cases, vancomycin can be nephrotoxic and damage the kidneys, especially when administered with aminoglycosides, another type of antibiotic.

Moreover, when administered with aminoglycosides or high-dose intravenous erythromycin, also another type of antibiotic, vancomycin can damage hearing (ototoxicity). Finally, vancomycin side effects can include hyperemia, or red-man syndrome, a type of flushing. Vancomycin red-man syndrome flushing can be mitigated if the patient is first given antihistamines.

A Word From Verywell

Vancomycin resistance poses a growing concern among clinicians, researchers, and epidemiologists alike. Because vancomycin is one of the last lines of defense against dangerous and drug-resistant diseases, the prospect that it will no longer work to combat infection is undeniably frightful and leaves few other options.

Specifically, strains of vancomycin-resistant enterococci have cropped up in hospitals worldwide. Because vancomycin is usually administered in hospitals, skilled-nursing facilities, nursing homes, and similar facilities, it's imperative that healthcare professionals take steps to limit vancomycin resistance. This can be done by curbing the overprescribing of drugs and limiting the spread of vancomycin resistance among patients through proper patient isolation and hygiene practices.