This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
The drug which is used for long term maintenance in opioid addiction: 
Select and explain. 
A. Naloxone, B. Nalorphine, C. Butarphamol, D. Methadione
D: Methadione
Answer: D: Methadione 
Explanation: D i.e. Methadone Naloxone is used in opioid overdoseQ and ultrarapid detoxification of opioid dependent (addicts)Q. Due to sho duration of action (t1/2 = 1-2 hour), frequent dosing is required, which makes it unsuitable for maintenance treatmentQ. Naltrexone & Nalmefene are used in rapid detoxification and maintenance of ultrarapid detoxification in opioid addicts (dependent). And methadone is used in sho term detoxification, long term detoxification & long term maintenance in opioid dependant (addicts)Q.