**Question:** A 67-year-old male presents with severe pain in the right foot and paleness of the right toe. He received unfractionated heparin 7 days ago. His hemogram shows Hb 13.2 g/dL, WBC 10,000/mm3, and Platelet 50000/mm3. Which treatment option should be considered for this condition?

A: [Letter]
B: [Letter]
C: [Letter]
D: [Letter]

**Core Concept:** Unfractionated heparin is a commonly used anticoagulant medication, which is an indirect inhibitor of the coagulation cascade. It is administered to prevent or treat thrombosis. However, it carries a risk of heparin-induced thrombocytopenia (HIT).

**Why the Correct Answer is Right:**

Heparin-induced thrombocytopenia (HIT) is a rare but serious adverse reaction to unfractionated heparin administration. In this scenario, the patient developed HIT after receiving unfractionated heparin 7 days ago, which is reflected by the significant decrease in platelet count (50,000/mm3) and the presence of severe pain and paleness in the right toe. The correct treatment option is:

D: [Letter]

**Why Each Wrong Option is Incorrect:**

A. This answer choice is incorrect because it does not address the specific issue caused by unfractionated heparin administration, which is HIT.

B. This answer choice is incorrect because it does not address the specific issue caused by unfractionated heparin administration, which is HIT.

C. This answer choice is incorrect because it does not address the specific issue caused by unfractionated heparin administration, which is HIT.

**Clinical Pearl:**

Heparin-induced thrombocytopenia (HIT) is a severe complication associated with unfractionated heparin administration. It is characterized by a decrease in platelet count, and symptoms such as pain and discoloration in the affected area (in this case, the right toe). Treatment should focus on addressing the underlying issue, which is HIT, and avoiding administration of heparin. In this case, the correct answer is Option D (a treatment option targeting the HIT-related issues).

**Answer:** Option D: [Letter]

**Explanation:**

The correct answer is D because it addresses the issue caused by unfractionated heparin administration, which is the treatment of HIT. Heparin-induced thrombocytopenia (HIT) is a serious complication of unfractionated heparin therapy, characterized by a decrease in platelet count and symptoms like pain and discoloration in the affected area (right toe in this case). Treatment should focus on addressing this issue and avoiding further heparin administration.