Cefaclor is which generation of cephalosporins?

• A. 1st gen
• B. 2nd gen
• C. 3rd gen
• D. 4th gen

Answer: (A)

Cefaclor is a second-generation cephalosporin. The generations reflect shifts in the antimicrobial spectrum: first-generation drugs are strong against Gram-positive cocci with modest Gram-negative activity; second-generation drugs add better coverage of certain Gram-negative bacteria such as Haemophilus influenzae and Enterobacteriaceae while keeping useful activity against Gram-positive cocci; third and fourth generations broaden Gram-negative coverage further and include agents with activity against Pseudomonas in some cases. Cefaclor fits the second-generation profile, offering improved Gram-negative coverage compared with first-generation cephalosporins but not the broad Pseudomonas activity seen in later generations. It’s commonly used for respiratory tract infections and otitis media, with good oral bioavailability.