**Core Concept:** Opioid addiction is a chronic relapsing brain disease characterized by compulsive drug-seeking and use, despite adverse consequences. Opioid receptor antagonists are used in opioid detoxification and maintenance therapy.

**Why the Correct Answer is Right:**
Drugs used for opioid de-addiction aim to block the effects of opioids, reducing cravings and withdrawal symptoms, and promoting recovery. Naltrexone is a selective mu-opioid receptor antagonist, and it is highly effective in preventing relapse in opioid-dependent individuals. It works by occupying the opioid receptors, preventing the effects of endogenous opioids and exogenous opioids, such as those found in heroin or prescription painkillers.

**Why Each Wrong Option is Incorrect:**
A. OxyContin (Percocet) is a prescription pain medication containing oxycodone, an opioid drug. It is not a de-addiction drug but can lead to addiction itself.
B. Suboxone (buprenorphine/naloxone) is a partial opioid agonist-antagonist, primarily used for opioid substitution therapy (not de-addiction).
C. Methadone is also an opioid agonist-antagonist (partial agonist), primarily used for opioid substitution therapy (not de-addiction).
D. Naloxone is a full mu-opioid antagonist used to reverse opioid overdose, not for de-addiction.

**Clinical Pearl:**
In clinical practice, naltrexone is often used in combination with other interventions like cognitive-behavioral therapy and support groups for better outcomes in opioid de-addiction. However, patients must be opioid-free for at least 7-10 days prior to initiating naltrexone treatment.

**Correct Answer:** D. Naltrexone (Naloxegol, Vivitrol) is a mu-opioid receptor antagonist, mainly used for opioid de-addiction therapy. The correct answer is Naltrexone, not Naloxone as mentioned in the question.