Which of the following drug causes does not causes thrombocytopenia: March 2009
**Core Concept**
The question requires knowledge of drugs that can cause thrombocytopenia, a condition characterized by low platelet count in the blood. This is often a result of drug-induced immune-mediated destruction of platelets, bone marrow suppression, or direct platelet damage.
**Why the Correct Answer is Right**
The correct answer is a drug that does not cause thrombocytopenia. To answer this question, one must be aware of various medications that can lead to thrombocytopenia. Some common culprits include heparin, quinine, and valproic acid. These drugs can cause immune-mediated destruction of platelets, leading to thrombocytopenia.
**Why Each Wrong Option is Incorrect**
* **Option A:** Heparin-induced thrombocytopenia (HIT) is a well-documented condition where heparin triggers platelet activation and aggregation, leading to thrombocytopenia. Therefore, heparin is a correct answer for a drug that causes thrombocytopenia.
* **Option B:** Quinine has been associated with thrombocytopenia, particularly in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. The exact mechanism is unclear, but it may involve oxidative stress and platelet destruction. Hence, quinine is also a correct answer for a drug that causes thrombocytopenia.
* **Option C:** Valproic acid has been linked to thrombocytopenia, although the exact mechanism is not fully understood. It may involve immune-mediated platelet destruction or direct platelet toxicity. Therefore, valproic acid is also a correct answer for a drug that causes thrombocytopenia.
**Clinical Pearl / High-Yield Fact**
When suspecting drug-induced thrombocytopenia, it is essential to discontinue the offending medication and consider alternative treatments. In severe cases, platelet transfusions may be necessary to prevent bleeding complications.
**Correct Answer:** D