Oral vancomycin may be given in: March 2012, March 2013
**Core Concept**
Oral vancomycin is a hydrophilic antibiotic that is poorly absorbed from the gastrointestinal tract, making it effective against Clostridioides difficile infections (CDI) in the colon. Its limited absorption from the gut is due to its low lipid solubility and the presence of a large molecular weight.
**Why the Correct Answer is Right**
The correct answer is related to the use of oral vancomycin for treating CDI. Oral vancomycin acts locally in the colon, where it achieves high concentrations that are effective against C. difficile toxins. The antibiotic is not absorbed systemically, which reduces the risk of side effects and allows the drug to remain effective in the colon. This is particularly important in treating CDI, as systemic absorption of vancomycin could lead to resistance and decreased efficacy.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because oral vancomycin is not used to treat systemic infections, such as bacteremia or endocarditis, which require intravenous administration.
**Option B:** This option is incorrect because oral vancomycin is not used to treat skin and soft tissue infections, which are typically treated with topical or intravenous vancomycin.
**Option C:** This option is incorrect because oral vancomycin is not used to treat respiratory infections, such as pneumonia, which are typically treated with intravenous antibiotics.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that oral vancomycin is not absorbed systemically, which makes it an ideal treatment for CDI. However, it is essential to note that oral vancomycin is not effective against systemic infections, and its use should be limited to treating localized infections in the gastrointestinal tract.
**Correct Answer: B. For C. difficile infections**