Which of the following is a common class of antibiotics?

• A. Macrolides
• B. Penicillins
• C. Beta-blockers
• D. Antihistamines

Answer: (B)

Penicillins represent a well-established and widely used class of antibiotics that play a critical role in the treatment of bacterial infections. They work by inhibiting bacterial cell wall synthesis, which leads to cell lysis and death. This mechanism of action makes penicillins effective against a variety of gram-positive bacteria and some gram-negative bacteria. Common examples of penicillins include amoxicillin and penicillin G.

In comparison, while macrolides are indeed another important class of antibiotics, the focus of the question is on identifying a common class within the broader context of antibiotic therapies where penicillins have historically been among the first discovered and extensively used. Antibiotics are distinct from beta-blockers and antihistamines, which are categorized as cardiovascular medications and allergy treatments, respectively, and they are not designed to treat bacterial infections. This highlights the fundamental difference in purpose and classification, solidifying penicillins as a correct choice when identifying common classes of antibiotics.