Which drug is used for CA-MRSA?

• A. Azithromycin
• B. Ceftriaxone
• C. Doxycycline
• D. Vancomycin

Answer: (C)

CA-MRSA infections are best treated with antibiotics that reliably cover MRSA in the community setting. Doxycycline fits this role well for mild-to-moderate skin and soft tissue infections because it has good oral bioavailability and activity against CA-MRSA, making it convenient for outpatient use.

Azithromycin often isn’t reliable against MRSA because resistance is common, and a macrolide like azithromycin may fail. Ceftriaxone is a beta-lactam that doesn’t cover MRSA well, since MRSA has reduced affinity for beta-lactams. Vancomycin does cover MRSA, but it requires IV administration and is typically reserved for more severe or hospital-acquired MRSA cases, not outpatient CA-MRSA.

So, doxycycline is the most appropriate choice for outpatient CA-MRSA treatment.