Vancomycin

Common Uses

Vancomycin is an antibiotic used to treat severe infections caused by certain types of bacteria. It is often reserved for infections that are resistant to other medications or for patients who cannot take other antibiotics like penicillins.

Digestive Tract Infections

When taken by mouth, vancomycin stays in the intestines and is not absorbed into the rest of the body. In this form, it is used to treat:

• Clostridioides difficile (C. diff): A bacterial infection that causes severe diarrhea and inflammation of the colon.
• Staphylococcal enterocolitis: Inflammation of the small intestine and colon caused by Staphylococcus aureus.

Systemic Infections

When given by injection into a vein, vancomycin travels through the bloodstream to treat serious infections in various parts of the body, including:

• Bloodstream infections (septicemia).
• Heart valve infections (endocarditis).
• Bone infections (osteomyelitis).
• Lung infections, such as pneumonia.
• Severe skin and soft tissue infections.
• Meningitis (infection of the lining around the brain and spinal cord).

It is a primary treatment for infections caused by methicillin-resistant Staphylococcus aureus (MRSA).

Mechanism of Action

Vancomycin belongs to a class of medications known as glycopeptide antibiotics. It works by interfering with the way bacteria construct their cell walls. The cell wall is a rigid outer layer that protects the bacteria and helps them maintain their shape. By binding to specific building blocks within the cell wall, vancomycin prevents these blocks from linking together properly.

Without a strong cell wall, the bacteria cannot survive the pressure within their own cells, causing them to burst and die. Because it kills the bacteria rather than just slowing their growth, it is considered a bactericidal antibiotic.

Targeted Bacteria

This medication is specifically effective against Gram-positive bacteria. It does not work for viral infections, such as the common cold or the flu.

Route of Action

The way vancomycin works in the body depends on how it is administered:

• Intravenous (IV) injection: When given by vein, the medication travels through the bloodstream to treat infections in various parts of the body, such as the blood, bones, or lungs.
• Oral (capsules or solution): When taken by mouth, vancomycin is not absorbed into the bloodstream. Instead, it stays in the digestive tract. This allows it to work directly on infections located in the intestines, such as Clostridioides difficile (C. diff).

Common Side Effects

Some people may experience mild side effects while taking vancomycin. These can include:

• Nausea or vomiting
• Stomach pain or gas
• Diarrhea
• Headache
• Back pain
• Bitter taste in the mouth (with oral forms)
• Redness, pain, or swelling at the injection site

Serious Side Effects

Contact a healthcare provider immediately if you experience any of the following serious symptoms:

• Signs of an allergic reaction, such as hives, skin rash, itching, or swelling of the face, lips, or throat
• Severe skin reactions, including blistering or peeling skin
• Changes in hearing, such as ringing in the ears or hearing loss
• Kidney problems, including decreased urination or swelling in the feet and lower legs
• Severe watery or bloody diarrhea
• Wheezing or difficulty breathing

When given by injection, vancomycin can cause a reaction if it is infused too quickly. This reaction may cause flushing or redness of the upper body, dizziness, and low blood pressure.

Kidney and Hearing Risks

Vancomycin may cause serious kidney problems or hearing loss. These risks are higher for older adults, individuals with existing kidney disease, or those taking other medications that affect the kidneys or hearing. Healthcare providers typically monitor blood levels and kidney function during treatment to ensure safety.

Infusion Reactions

When given intravenously, rapid administration can lead to infusion-related reactions, sometimes referred to as red man syndrome. Symptoms include flushing of the upper body, hives, itching, and low blood pressure. To minimize this risk, the medication is typically infused slowly over at least 60 minutes.

Severe Skin Reactions

Serious skin reactions, such as Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) and Stevens-Johnson syndrome, have been reported. Treatment is usually discontinued if a new rash or skin peeling occurs.

Other Precautions

• Neutropenia: Long-term use may cause a decrease in white blood cells. Periodic blood counts may be necessary for those on extended therapy.
• Diarrhea: Like many antibiotics, vancomycin can cause Clostridioides difficile-associated diarrhea, which ranges in severity from mild to life-threatening.
• Pregnancy and Breastfeeding: The intravenous form should be used during pregnancy only if clearly needed. It is unknown if vancomycin is excreted in human milk, so caution is advised for breastfeeding individuals.

Contraindications

Vancomycin is contraindicated in individuals with a known hypersensitivity to the medication.

Pregnancy

There is limited information regarding the use of vancomycin in pregnant women. When administered intravenously, vancomycin can cross the placenta and enter the fetal circulation. While some studies have not shown an increased risk of birth defects or hearing loss in infants exposed to the drug during the second or third trimesters, comprehensive data is lacking. Oral vancomycin is generally not absorbed into the bloodstream in significant amounts, which may limit fetal exposure.

Breastfeeding

Vancomycin is known to pass into human breast milk when given by injection. It is not known whether the drug causes harmful effects in nursing infants or if it affects milk production. Because many drugs are excreted in human milk and the potential for adverse reactions exists, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the medication to the mother.

If you are pregnant, planning to become pregnant, or breastfeeding, discuss the risks and benefits of vancomycin treatment with your healthcare provider.

Oral Forms

Vancomycin is available in the following oral preparations:

• Capsules: These are typically used for treating certain infections in the digestive tract.
• Oral Solution: This is often provided as a powder that is mixed with water by a pharmacist to create a liquid for swallowing.

Injectable Forms

For systemic infections, vancomycin is administered by injection into a vein. It is available as:

• Powder for Injection: A concentrated powder in vials that must be dissolved and further diluted by a healthcare professional before intravenous infusion.
• Premixed Injection: Ready-to-use liquid solutions for infusion that do not require initial reconstitution.

The specific form and strength used depend on the location and severity of the infection, as well as the patient's age and kidney function.

FDA Approval Status

Vancomycin is an FDA-approved glycopeptide antibiotic. It was first approved in 1958 and remains a primary treatment for serious infections caused by Gram-positive bacteria that are resistant to other antibiotics.

Approved Indications

The FDA has approved vancomycin for different uses depending on the route of administration:

• Oral administration: Approved only for the treatment of Clostridioides difficile-associated diarrhea and enterocolitis caused by Staphylococcus aureus. It is not effective for systemic infections when taken orally because it is not absorbed into the bloodstream.
• Intravenous administration: Approved for severe infections including septicemia, infective endocarditis, bone infections, lower respiratory tract infections, and skin structure infections caused by susceptible strains of methicillin-resistant staphylococci.

Regulatory Safety and Oversight

Vancomycin is available by prescription only. There are currently no FDA boxed warnings or Risk Evaluation and Mitigation Strategies (REMS) associated with vancomycin. To maintain its effectiveness and reduce the development of drug-resistant bacteria, regulatory labeling specifies that vancomycin should be used only for infections proven or strongly suspected to be caused by susceptible organisms.

Overview of IV Administration

Vancomycin is delivered through a needle or catheter into a vein to treat severe infections such as endocarditis, osteomyelitis (bone infection), and pneumonia. It is a primary treatment for methicillin-resistant Staphylococcus aureus (MRSA). Because vancomycin is not absorbed into the bloodstream when taken orally, the IV route is necessary for systemic infections.

Infusion Rate and Safety

The medication must be infused slowly to minimize the risk of adverse reactions. A typical dose is administered over at least 60 minutes. Rapid infusion can lead to a condition often called "red man syndrome," which is characterized by:

• Flushing or redness of the face, neck, and upper body
• Itching or hives
• A sudden drop in blood pressure (hypotension)
• Shortness of breath or wheezing

Monitoring and Precautions

Healthcare providers monitor patients closely during treatment to ensure the medication is effective and to prevent toxicity. Monitoring typically includes:

• Blood levels: Regular tests to check the concentration of vancomycin in the blood (trough levels) to adjust the dosage.
• Kidney function: Periodic tests to monitor for nephrotoxicity, as the drug can cause kidney damage, especially in older adults or those with pre-existing renal issues.
• Hearing tests: Assessment for ototoxicity (hearing loss or ringing in the ears), which may occur if drug levels become too high.

Patients should report any pain, swelling, or redness at the injection site, as vancomycin can cause irritation or inflammation of the vein (thrombophlebitis).