Which of the following drugs is not used in opioid dependence?

Treatment of opioid dependence 1)   Detoxification (treatment of withdrawal syndrome) Methadone is the DOC Alternatives:- Buprenorphine, LAAM, clonidine, clonidine with naltrexone with or without benzodiazepines (Lorazepam, oxazepam), Lofexidine, Dextropropoxyphene, diphenoxylate. 2)   Maintenance (to prevent relapse) Methadone is the DOC Alternatives:- Buprenorphine, LAAM, opioid antagonists (Naltrexone).