Question

One advantage of semisynthetic penicillin

Answer 1

Penicillin G (naturally occurring) is poorly stable in gastric acid and broken down rapidly as it passes through the stomach. Therefore, Penicillin G must be given intramuscularly which limits its usefulness. Semisynthetic penicillins such as Amoxycillin with increased oral bioavailability were a major advancement in therapeutic antibiotics. Furthermore, while aminopenicillins and natural penicillins have similar efficacy against gram positive bacteria, semisynthetic aminopenicillins (such as Amoxycillin) are more active against certain strains of gram negative rods.