Final answer:
The three main preparations of Penicillin G are Penicillin G sodium, Penicillin G potassium (both intravenous or intramuscular), and long-acting benzathine penicillin (intramuscular), primarily used for syphilis treatment.
Step-by-step explanation:
The three main preparations of Penicillin G include:
The efficacy of Penicillin G against gram-positive bacteria and some gram-negative bacteria makes it a strong choice for treating various infections such as diphtheria, gonorrhea, pneumonia, and syphilis. Unlike other penicillins like Penicillin V, ampicillin, and amoxicillin, Penicillin G cannot be taken orally due to its instability in acidic environments like the stomach.