Which cephalosporin would have the best gram positive and gram negative coverage?

• A. Cephalexin
• B. Ceftriaxone
• C. 1st generation Cephalosporin
• D. 2nd generation Cephalosporin

Answer: (B)

Ceftriaxone, a third-generation cephalosporin, offers a broad spectrum that includes many gram-negative bacteria (such as Enterobacteriaceae and Neisseria) while still providing solid activity against gram-positive cocci like Streptococcus species. This combination makes it a balanced choice when infections could involve either gram-positive or gram-negative organisms. Its pharmacokinetics also support its use in mixed infections and meningitis due to good tissue penetration and convenient once-daily dosing. It’s important to note that it does not reliably cover MRSA or Pseudomonas, which explains why it’s not the best choice if those pathogens are suspected.