## **Core Concept**
The question tests knowledge of drugs associated with peripheral neuropathy, a condition characterized by damage to the peripheral nerves, often causing weakness, numbness, and pain. Peripheral neuropathy can be caused by various factors, including certain medications.

## **Why the Correct Answer is Right**
Isoniazid is a well-known antitubercular agent that can cause peripheral neuropathy as a side effect. This occurs due to its interference with pyridoxine (Vitamin B6) metabolism. Isoniazid forms a hydrazone with pyridoxal phosphate, which is then excreted, leading to a deficiency of pyridoxine. Pyridoxine is essential for the synthesis of myelin and the maintenance of the nervous system. A deficiency can result in neuropathy.

## **Why Each Wrong Option is Incorrect**
- **Option A:** While certain antineoplastic agents can cause neuropathy, the specific association and mechanism might differ from isoniazid.
- **Option B:** Though some antiviral drugs can cause neuropathy, they are not as classically associated with this side effect as isoniazid.
- **Option D:** This option might be related to other side effects or less commonly associated with peripheral neuropathy compared to isoniazid.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that isoniazid-induced neuropathy can be prevented by administering pyridoxine (Vitamin B6) supplements. This is a critical preventive measure, especially in high-risk patients.

## **Correct Answer:** . Isoniazid