Roxanne, a 23-year-old medical student, arrives at the student health clinic complaining of difficulty in swallowing, a sore throat, and chills. Upon examination, she is found to be running a fever and has white patches on her tonsils. A throat swab is positive for Streptococcus pyogenes (group A). A diagnosis of acute pharyngitis is made. Her past medical history is unremarkable except for an anaphylactic reaction to cefaclor two years ago.

Which of the following would be a safe alternative for treating Roxanne's condition?

A. amoxicillin, oral
B. cephalexin, oral
C. clindamycin
D. meropenem
E. nafcillin

Given Roxanne's history of anaphylactic reaction to cefaclor, clindamycin is a safe alternative for treating her acute pharyngitis caused by Streptococcus pyogenes, as it avoids potential allergic reactions associated with beta-lactam antibiotics.

Explanation:

Roxanne, a 23-year-old medical student, presents with symptoms consistent with acute pharyngitis caused by Streptococcus pyogenes. Considering her past anaphylactic reaction to cefaclor, a safe alternative for treating Roxanne's condition would be clindamycin. This choice avoids the use of beta-lactam antibiotics, like amoxicillin and cephalexin, which could potentially trigger an allergic reaction due to their structural similarity to cefaclor.

Meropenem and nafcillin are also avoided because they fall into the broader category of beta-lactam antibiotics, posing a risk for cross-reactivity in patients with a history of severe reactions to this class. Clindamycin, on the other hand, is a lincosamide antibiotic with a different mechanism of action, making it a safer choice for patients with beta-lactam allergies. It's effective against S. pyogenes and can be used to treat streptococcal infections, including pharyngitis, in patients who cannot tolerate beta-lactams.