Which medication is often used in the treatment of bacterial infections and belongs to the penicillin family?

Penicillin VK is specifically used to treat a variety of bacterial infections due to its origin in the penicillin family. This antibiotic works by inhibiting bacterial cell wall synthesis, ultimately leading to the destruction of the bacteria. It's particularly effective against certain types of bacteria and is commonly prescribed for infections like strep throat or mild pneumonia.

Cefalexin, while also an antibiotic, belongs to the cephalosporin class rather than the penicillin family, and thus does not fit the parameters of the question. Azithromycin is a macrolide antibiotic, used to treat different types of infections such as respiratory and skin infections, but it is not part of the penicillin family. Lisinopril is an entirely different type of medication known as an ACE inhibitor, primarily used to manage high blood pressure and heart failure, making it irrelevant to the treatment of bacterial infections.