American Board of Internal Medicine (ABIM) Certification Practice Exam

For outpatient treatment of a previously healthy CAP patient, which antibiotic may be used as an alternative?

1. Amoxicillin

2. Clarithromycin

3. Aminoglycoside

4. Ciprofloxacin

The correct answer is: Clarithromycin

The choice of clarithromycin as an alternative antibiotic for the outpatient treatment of a previously healthy patient with community-acquired pneumonia (CAP) is based on its efficacy against common respiratory pathogens. Clarithromycin is a macrolide antibiotic that is effective against Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae, which are frequently responsible for CAP. In patients who are previously healthy, guidelines typically recommend a macrolide like clarithromycin or doxycycline as appropriate first-line agents if the patient has no specific risk factors for resistant organisms. Clarithromycin can also be particularly appealing for outpatient treatment due to its convenient dosing schedules and established safety profile. Other options, while potentially effective in certain contexts, are not as standard for the treatment of uncomplicated CAP in previously healthy individuals. Amoxicillin is also a correct option for typical pneumonia treatment, but when considering alternatives, clarithromycin maintains a key position due to its broader coverage of potential atypical pathogens. Aminoglycosides, while potent, are generally reserved for more severe infections, and they are not the preferred agents for outpatient treatment due to their side effect profiles and the need for monitoring. Ciprofloxacin, while a fluoroquinolone that