<s>[INST] context: The opioid antagonist naloxone reverses the effects of a dose of morphine or heroin within minutes. This may be life-saving in the case of a massive overdose. Naloxone administration also provokes an acute withdrawal syndrome in a dependent person who has recently taken an opioid. In the treatment of opioid addiction, a long-acting opioid (eg, methadone, buprenorphine ) is often substituted for the shoer-acting, more rewarding, opioid (eg, heroin). The signs and symptoms of withdrawal include a lot of distressing symptoms which makes the patient take the substance again. the symptoms of opiod withdrawl are remebered witha clue" ALL ORIFICES BLEED" the symptoms include rhinorrhea, lacrimation, yawning, chills, gooseflesh (piloerection), hyperventilation, hypehermia, mydriasis, muscular aches, vomiting, diarrhoea, anxiety, and hostility. the detoxification of opiod withdrawl is done by 3 methods that are listed below 1.SYMPTOMATIC DETOXIFICATION============clonidine, diazepam, dicyclomine, anti emetic, anti diarrhoeal 2.AGONIST ASOSIATED DETOXIFICATION========methadone, bupenorphine 3.ANTAGONIST ASSOSIATED DETOXIFICATION=====naltrexone STRONG OPIOID AGONISTS Morphineentanyl PAIAL AGONISTS CodeineHydrocodone MIXED OPIOID AGONIST-ANTAGONISTS BuprenorphineNalbuphine OPIOID ANTAGONISTS Naloxone [/INST] question: Methadone is used for opioid withdrawal because | options: A: Its antagonist at opioid receptor B: Its paial antagonist at opioid receptor C: Its agonist at opioid receptor D: Its paial agonist at opioid receptor | answer: C </s>