Which is a selective cyclooxygenase-2 inhibitor ?
**Core Concept**
Cyclooxygenase-2 (COX-2) is an enzyme involved in the production of prostaglandins, which play a crucial role in inflammation and pain. Selective COX-2 inhibitors are a class of nonsteroidal anti-inflammatory drugs (NSAIDs) that target this enzyme specifically, reducing gastrointestinal side effects associated with traditional NSAIDs.
**Why the Correct Answer is Right**
The mechanism of action of selective COX-2 inhibitors involves the inhibition of COX-2 enzyme, thereby reducing the production of prostaglandins. This leads to decreased inflammation and pain without affecting the production of protective prostaglandins in the stomach, thus reducing the risk of gastrointestinal side effects. Examples of COX-2 inhibitors include celecoxib and meloxicam.
**Why Each Wrong Option is Incorrect**
**Option A:** This drug is a traditional NSAID that inhibits both COX-1 and COX-2 enzymes, increasing the risk of gastrointestinal side effects.
**Option B:** This drug is a non-selective COX inhibitor that also inhibits COX-1, leading to increased risk of gastrointestinal ulcers and bleeding.
**Option C:** This drug is a COX-1 selective inhibitor, which can lead to an increased risk of gastrointestinal side effects due to the inhibition of protective prostaglandins.
**Clinical Pearl / High-Yield Fact**
Selective COX-2 inhibitors are preferred in patients with a high risk of gastrointestinal bleeding or those taking anticoagulants. However, they may increase the risk of cardiovascular events and are not recommended for patients with cardiovascular disease.
**Correct Answer: C. Meloxicam**