What is mechanism of action of colchicine in acute gout?
**Core Concept**
Colchicine is a medication used to treat gout attacks, and its mechanism of action involves disrupting microtubule dynamics in neutrophils. This leads to a decrease in neutrophil migration and accumulation in the joints, which is a key feature of gout inflammation.
**Why the Correct Answer is Right**
Colchicine binds to tubulin, a subunit of microtubules, and inhibits its polymerization into microtubules. This disrupts the microtubule network within neutrophils, leading to a delay in their migration and a reduction in their accumulation in the joint space. As a result, the inflammatory response in gout is attenuated.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because colchicine does not directly inhibit the production of pro-inflammatory cytokines.
**Option B:** Incorrect because colchicine does not block the action of bradykinin, which is a vasodilator involved in inflammation.
**Option C:** Incorrect because colchicine does not directly inhibit the enzyme xanthine oxidase, which is involved in the production of uric acid.
**Clinical Pearl / High-Yield Fact**
Colchicine is most effective when administered early in the course of a gout attack, as its mechanism of action is most beneficial in reducing the severity and duration of the inflammatory response.
**Correct Answer:** C. Colchicine binds to tubulin, a subunit of microtubules, and inhibits its polymerization into microtubules.