From the Research
Intravenous (IV) and oral vancomycin can be used together in specific clinical scenarios, primarily for severe Clostridioides difficile infection (CDI), where IV vancomycin treats systemic infections while oral vancomycin targets the intestinal infection. The use of both IV and oral vancomycin is based on the principle that oral vancomycin is not significantly absorbed from the gastrointestinal tract, allowing it to reach high concentrations in the intestinal lumen where C. difficile resides, while IV vancomycin addresses any systemic involvement 1. For severe or fulminant CDI, a typical regimen includes IV metronidazole 500 mg every 8 hours plus oral vancomycin 125-500 mg four times daily for 10-14 days. Key considerations when administering both routes include:
- Monitoring for cumulative toxicity, particularly nephrotoxicity and ototoxicity, especially in patients with renal impairment 2
- Therapeutic drug monitoring of IV vancomycin to maintain appropriate trough levels between 15-20 mg/L for serious infections 3
- The choice between intermittent and continuous infusion of vancomycin, with continuous infusion potentially offering more stable serum concentrations and earlier achievement of therapeutic levels 2, 3 It's essential to note that oral vancomycin alone is usually sufficient for most cases of CDI, and the IV component is added only for severe cases with systemic symptoms 4, 5. The most recent and highest quality study on the topic, published in 2021, found no significant differences in recurrence, clinical failure, mortality, or re-admission between patients receiving standard and high-dose oral vancomycin for CDI treatment 5. Therefore, the decision to use IV and oral vancomycin together should be made on a case-by-case basis, considering the severity of the infection, the patient's renal function, and the potential risks and benefits of combination therapy.