American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended prophylactic treatment for dog bites in patients without allergies to β-lactam antibiotics?

1. Short course of piperacillin-tazobactam

2. 3- to 5-day course of amoxicillin-clavulanate

3. Long course of doxycycline

4. Single dose of fluoroquinolone

The correct answer is: 3- to 5-day course of amoxicillin-clavulanate

The recommended prophylactic treatment for dog bites in patients without allergies to β-lactam antibiotics is a 3- to 5-day course of amoxicillin-clavulanate. This antibiotic combination is effective against the polymicrobial flora typically found in dog bites, which includes potential pathogens such as Pasteurella multocida, as well as anaerobes and other common bacteria present in animal mouths. Amoxicillin-clavulanate is particularly advantageous because it not only covers streptococci and staphylococci but also protects against β-lactamase-producing organisms, making it a comprehensive choice for bite wounds. The recommended duration of 3 to 5 days is sufficient to prevent infection without the potential for unnecessary extended use of antibiotics. In contrast, the other treatments listed are not ideal for this situation. Piperacillin-tazobactam, while effective for more severe infections, is not typically used for uncomplicated dog bites due to its wider spectrum and increased risk of side effects. Doxycycline is not the first-line agent for dog bites, as it primarily covers certain bacteria but lacks coverage for some of the typical pathogens involved. A single dose of fluoroquinolone might provide some coverage but is insufficient for prophylaxis and