Acid susceptible penicillin is :
**Core Concept**
Acid-susceptible penicillins are a group of beta-lactam antibiotics that are unstable in acidic environments, such as the stomach. These antibiotics are inactivated by gastric acid, which reduces their bioavailability and efficacy when administered orally.
**Why the Correct Answer is Right**
The correct answer is a type of penicillin that is inactivated by gastric acid, making it less effective when taken orally. Acid-susceptible penicillins, such as penicillin G and ampicillin, are rapidly hydrolyzed by stomach acid, resulting in a decrease in their antibacterial activity. This is in contrast to acid-stable penicillins, such as amoxicillin and piperacillin, which are resistant to inactivation by gastric acid.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because penicillin G is an acid-susceptible penicillin.
**Option B:** This option is incorrect because ampicillin is also an acid-susceptible penicillin.
**Option C:** This option is incorrect because amoxicillin is an acid-stable penicillin.
**Clinical Pearl / High-Yield Fact**
To maximize the efficacy of acid-susceptible penicillins, they should be administered parenterally (intravenously or intramuscularly) to bypass the acidic environment of the stomach.
**Correct Answer: A. Penicillin G**