Which antibiotics are effective against Gram-negative rods (GNRs)?

Cefepime and Ceftazidime are cephalosporin antibiotics that have proven effectiveness against Gram-negative rods (GNRs). Both of these medications belong to the fourth generation of cephalosporins, which are specifically designed to cover a broad spectrum of bacteria, including many strains of GNRs.

Cefepime is particularly effective against a wide range of GNRs, including Pseudomonas aeruginosa, and is often used in treating serious infections where resistant bacteria may be involved. Ceftazidime also has strong activity against Pseudomonas and other GNRs. This enhanced efficacy stems from their ability to penetrate the outer membrane of Gram-negative bacteria and resist degradation by certain β-lactamases, which can render other antibiotics ineffective.

In contrast, the other antibiotic options listed are less effective or not effective against GNRs. Penicillin and Amoxicillin primarily target Gram-positive bacteria, with limited coverage of some GNRs, particularly those that produce β-lactamase enzymes. Carbapenems are indeed effective against many GNRs but are not specifically classified under the cephalosporins, which is why they are not the correct choice for this question. Macrol