Which group of penicillins includes drugs resistant to penicillinase?

The group of penicillins that includes drugs resistant to penicillinase is the penicillinase-resistant penicillins. These penicillins, such as methicillin, nafcillin, and oxacillin, are chemically modified to withstand the hydrolytic action of penicillinase (also known as beta-lactamase), which is an enzyme produced by certain bacteria that inactivates many types of penicillin. Their structure includes bulky side chains that prevent the enzyme from effectively binding and breaking down the antibiotic, thus providing effective treatment against penicillinase-producing staphylococci and some other resistant bacteria.

In contrast, aminopenicillins are effective against a broader spectrum of gram-positive and some gram-negative bacteria, but they are still susceptible to penicillinase. Natural penicillins, like penicillin G and V, are also susceptible to penicillinase and thus are not effective against penicillinase-producing organisms. Antipseudomonal penicillins, such as piperacillin, are designed to target Pseudomonas aeruginosa but do not offer resistance to penicillinase without the modification present in penicillinase-resistant penicillins. Therefore, the unique ability of penicillin