What is the common form of Penicillin used to treat infections?

Penicillin VK is a commonly prescribed form of penicillin that is effective in treating various bacterial infections. It is a narrow-spectrum antibiotic, meaning it primarily targets specific types of bacteria, which makes it especially useful for conditions like strep throat, skin infections, and other infections caused by susceptible organisms. Penicillin VK is often chosen for oral administration due to its stability in the gastrointestinal tract, making it suitable for outpatients.

In the context of the other options, Amoxicillin is indeed related to penicillin and is also used to treat infections, but it is a broader-spectrum antibiotic and not classified solely as penicillin. Ciprofloxacin and Doxycycline are both antibiotics but belong to different classes—fluoroquinolones and tetracyclines, respectively—and are used for a wider range of infections not specifically targeted by penicillin. Thus, Penicillin VK stands out as the correct answer for a common form of penicillin specifically used to treat infections.