Which of the following is a penicillinase-resistant penicillin?

Penicillinase-resistant penicillins are specifically designed to combat bacterial resistance mechanisms, particularly the production of penicillinase, which can inactivate many types of penicillin antibiotics. Dicloxacillin is categorized as a penicillinase-resistant penicillin because it possesses a bulky side chain that prevents the enzyme from effectively binding and breaking down the antibiotic.

This antibiotic is commonly used to treat infections caused by penicillinase-producing staphylococci, making it an important choice in the management of certain types of bacterial infections. Its structure allows it to remain effective against these resistant strains, thereby enhancing its clinical utility in settings where such methicillin-resistant organisms are prevalent.

In contrast, options like amoxicillin, carbenicillin, and piperacillin do not share this specific protective feature against penicillinase-producing bacteria, which can limit their effectiveness in certain clinical scenarios where resistance is a concern.