**Core Concept**
Heroin dependence is managed with medications that reduce cravings, mitigate withdrawal symptoms, and stabilize the patient. Treatment focuses on opioid receptor modulation, stress response regulation, and preventing relapse, not on inhibiting alcohol metabolism.

**Why the Correct Answer is Right**
Disulfiram is used in alcohol dependence to inhibit aldehyde dehydrogenase, causing acetaldehyde accumulation when alcohol is consumed. It has no role in opioid dependence and does not act on opioid receptors or withdrawal pathways. In contrast, buprenorphine (a partial opioid agonist) reduces cravings and withdrawal, clonidine (an alpha-2 agonist) reduces autonomic symptoms of withdrawal, and lofexidine (a newer alpha-2 agonist) specifically treats opioid withdrawal with fewer side effects.

**Why Each Wrong Option is Incorrect**
Option B: Buprenorphine is a first-line medication for opioid dependence, acting as a partial agonist at mu-opioid receptors to reduce withdrawal and cravings.
Option C: Clonidine reduces sympathetic overactivity during withdrawal by activating alpha-2 receptors in the brainstem.
Option D: Lofexidine is approved for opioid withdrawal, specifically targeting alpha-2 receptors with improved tolerability over clonidine.

**Clinical Pearl / High-Yield Fact**
Never use disulfiram in opioid dependence—its mechanism is specific to alcohol metabolism. Always remember: **"Disulfiram = Alcohol, not Opioids."**

✓ Correct Answer: A. Disulfiram