What is the Best Way to Take Vancomycin? Your Guide to Oral and IV Administration

October 12, 2025 •

4 min read

The correct administration route of vancomycin is crucial for effective treatment, making it vital to understand what is the best way to take vancomycin for your specific infection.

Quick Summary

The most effective way to take vancomycin depends on the infection. Oral administration treats intestinal infections, while intravenous therapy is required for systemic infections. Proper administration and monitoring are essential for both routes to maximize effectiveness and minimize side effects.

Key Points

Route of Administration: The best way to take vancomycin is determined by the infection's location; oral for gut infections, and intravenous (IV) for systemic infections.
Oral Administration for C. difficile: Oral vancomycin is effective for intestinal infections because it is poorly absorbed, keeping the antibiotic concentrated in the gut where it is needed.
Intravenous Administration for MRSA: IV vancomycin is necessary for serious systemic infections like MRSA because it enters the bloodstream to reach affected areas throughout the body.
Monitoring is Crucial for IV Use: Patients on IV vancomycin require therapeutic drug monitoring, often with AUC-guided administration, to balance effectiveness with the risks of kidney and hearing damage.
Prevention of Side Effects: IV vancomycin must be infused slowly to prevent "red man syndrome," an infusion-related reaction.
Complete the Full Course: For all forms of vancomycin, it is vital to complete the entire prescribed course to ensure the infection is fully treated and to prevent antibiotic resistance.

Choosing the Correct Administration Route

Vancomycin is a powerful glycopeptide antibiotic, but its effectiveness is determined by how it is administered. It is not a one-size-fits-all medication; the route of delivery must match the infection's location. Taking the medication incorrectly, such as using the oral form for a bloodstream infection, will not work and can contribute to antibiotic resistance. The two primary methods are oral and intravenous (IV).

Oral Vancomycin: For Gut-Based Infections

When vancomycin is taken by mouth, it is poorly absorbed into the bloodstream. This property is highly beneficial for treating infections confined to the intestines, such as colitis and diarrhea caused by Clostridioides difficile (C. difficile). The antibiotic stays in the gastrointestinal tract, where it can act directly on the bacteria. Oral vancomycin comes in capsules and a liquid solution.

Guidelines for Oral Vancomycin

Shake liquid formulations: If using the oral solution, shake the bottle well before each use to ensure even mixing.
Use the right tool: Measure liquid doses using a special measuring spoon or oral syringe, not a household teaspoon, to ensure accuracy.
Follow the schedule: Take the medication exactly as prescribed. Adhering to the schedule is critical, even if you feel better sooner.
Monitor for side effects: Common side effects include nausea, stomach pain, and diarrhea. In rare cases, more serious issues like kidney injury or hearing loss can occur. Report any severe or persistent side effects to your doctor.
No routine monitoring: Due to its poor systemic absorption, oral vancomycin does not require routine serum level monitoring, unlike the IV form.

Intravenous Vancomycin: For Systemic Infections

For most serious infections, vancomycin is administered intravenously (IV) in a hospital or clinic setting. This method is used when the bacteria are located throughout the body, such as in bloodstream infections, endocarditis, or bone and joint infections, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). It is important to remember that IV vancomycin is not effective for treating C. difficile infection because it doesn't adequately reach the intestinal tract.

Guidelines for IV Vancomycin

Slow infusion: The medication must be infused slowly to prevent a common adverse reaction called "red man syndrome". This reaction is characterized by flushing, itching, and a rash on the face, neck, and upper body.
Therapeutic drug monitoring: IV vancomycin requires careful monitoring of serum drug levels due to its narrow therapeutic index, meaning there's a small window between an effective concentration and a toxic one. Current guidelines recommend using AUC (Area Under the Curve)-guided administration, which more accurately reflects a patient's overall drug exposure, over the older trough-only method.
Watch for toxicity: Higher concentrations or prolonged therapy can increase the risk of serious side effects, primarily nephrotoxicity (kidney damage) and ototoxicity (hearing damage).
Administration adjustments: Administration is individualized based on factors like weight, age, and kidney function. Patients with impaired renal function, the elderly, and those receiving other nephrotoxic drugs require special attention and more frequent monitoring.

Comparison of Oral vs. IV Vancomycin


Feature	Oral Vancomycin	IV Vancomycin
Indication	Infections confined to the gut, such as C. difficile colitis and staphylococcal enterocolitis.	Systemic infections, including MRSA, endocarditis, pneumonia, and sepsis.
Absorption	Very low systemic absorption, stays primarily in the intestines.	High systemic absorption, enters the bloodstream to treat infections throughout the body.
Monitoring	Not routinely required due to poor absorption.	Essential, with modern practice favoring AUC-guided therapeutic drug monitoring to ensure efficacy and minimize toxicity.
Key Risks	Gastrointestinal upset, but can have systemic side effects (like nephrotoxicity) in rare cases or in patients with bowel inflammation.	Higher risk of nephrotoxicity, ototoxicity, and "red man syndrome" if infused too quickly.
Administration	Capsules or liquid taken by mouth.	Administered slowly via an intravenous line.

Best Practices for All Patients

Regardless of the administration route, following best practices is essential for safe and effective vancomycin treatment.

Communicate with your doctor: Always provide a complete medical history, including any kidney or hearing issues, to your healthcare provider.
Complete the full course: Do not stop taking vancomycin prematurely, even if your symptoms improve. Stopping early can lead to recurring infection and increase the risk of antibiotic resistance.
Report side effects: Immediately report any serious side effects like hearing changes, signs of kidney problems (e.g., decreased urination), or allergic reactions to your medical team.
Storage instructions: Store oral solutions in the refrigerator and capsules at room temperature, unless otherwise directed.

Conclusion

The answer to "what is the best way to take vancomycin?" is not a single route but rather the one that is appropriate for the specific infection being treated. Oral vancomycin effectively targets gastrointestinal infections like C. difficile, while IV administration is the standard for serious systemic infections like MRSA. Following medical guidance on the correct route and monitoring is vital for maximizing the drug's effectiveness and minimizing the risk of adverse effects.

For more information on the proper usage and administration of vancomycin, consult reliable resources like the MedlinePlus Drug Information page.

Frequently Asked Questions

Vancomycin is taken orally for infections limited to the intestines, such as C. difficile colitis, because it is not significantly absorbed into the bloodstream. It is administered intravenously for systemic infections, like MRSA, where the antibiotic needs to circulate throughout the body.

Oral vancomycin is not effective for systemic infections because it is poorly absorbed from the gastrointestinal tract. Consequently, it does not reach high enough concentrations in the blood to treat infections in other parts of the body.

Red man syndrome is an infusion-related reaction that can occur if IV vancomycin is administered too quickly. Symptoms include flushing and itching of the upper body. It can be avoided by infusing the medication slowly.

Blood level monitoring for IV vancomycin is essential because the drug has a narrow therapeutic index. Monitoring helps ensure the concentration is high enough to be effective but not so high as to cause toxicity, particularly kidney damage (nephrotoxicity) and hearing loss (ototoxicity).

The duration of vancomycin treatment depends on the type and severity of the infection. Always complete the full course as prescribed by your doctor, even if your symptoms improve.

Common side effects of oral vancomycin include nausea, vomiting, stomach pain, diarrhea, and gas. It is important to contact your doctor if any side effects are severe or do not go away.

Yes, IV vancomycin can cause kidney damage, or nephrotoxicity, especially with prolonged treatment or higher concentrations. This risk is managed through careful administration adjustments and regular monitoring of serum levels and kidney function.