National Dental Examining Board of Canada (NDEB) Practice Exam

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Prepare for the National Dental Examining Board of Canada (NDEB) Test. Study with flashcards and multiple choice questions, each question offers hints and detailed explanations. Achieve success in your exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

Which penicillin is least resistant to the level of acidity in the stomach?

Ampicillin
Amoxicillin
Benzylpenicillin
Cloxacillin

The correct answer is: Benzylpenicillin

The reason why the other options are incorrect is because ampicillin, amoxicillin, and cloxacillin are all semi-synthetic penicillins and thus have been chemically modified to be more resistant to stomach acid. Cloxacillin, in particular, has a side chain that makes it more resistant to stomach acid. However, benzylpenicillin is not a semi-synthetic penicillin and has no additional modifications to make it more resistant to stomach acid. Therefore, it is the least resistant to the acidic conditions in the stomach.