Drug reaction caused by ampicillin: March 2011
**Core Concept**
Ampicillin is a penicillin antibiotic that can cause a hypersensitivity reaction in some individuals. This reaction is mediated by the immune system and can manifest as an allergic response.
**Why the Correct Answer is Right**
The correct answer is related to the mechanism of hypersensitivity reaction to ampicillin. Ampicillin can bind to IgE antibodies on mast cells, leading to the release of histamine and other chemical mediators. This results in symptoms such as hives, itching, swelling, and anaphylaxis. The specific drug reaction caused by ampicillin is an example of a type I hypersensitivity reaction.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not a known side effect of ampicillin. Ampicillin is not associated with hepatotoxicity.
**Option B:** Incorrect because it is not a common side effect of ampicillin. While ampicillin can cause gastrointestinal upset, it is not typically associated with pancreatitis.
**Option C:** Incorrect because it is not a specific side effect of ampicillin. Ampicillin is not typically associated with a specific neurological side effect like asterixis.
**Clinical Pearl / High-Yield Fact**
Ampicillin can cause a false-positive result in the Coombs test, which is used to detect autoimmune hemolytic anemia.
**Correct Answer:** D.