IRCT201207196972N2 IRCT 2012-08-30 Research Vice Chancellor of Tabriz University of Medical Sciences The effects of a combination therapy of clonidine with dextromethorphan and/or amantadine on opium withdrawal syndrome compared with the single therapy of clonidine CCDAOW Study of the effects of a combination therapy of clonidine with dextromethorphan and/or amantadine on opium withdrawal syndrome compared with the single therapy of clonidine 2011-06-07 anticipated 120 Complete https://irct.ir/trial/7427 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. N/A Mental and behavioural disorders due to use of opioids. Intervention 1: The first group will receive clonidine tablet 0.4-1.2 mg per day in three subdivided doses according to the patient's tolerance, clonazepam tablet one mg per eight hours and acetaminophen tablet 500 mg every six hours. Intervention 2: The second group will receive clonidine tablet 0.4-1.2 mg per day in three subdivided doses according to the patient's tolerance, clonazepam tablet one mg per eight hours,acetaminophen tablet 500 mg every six hours and amantadine capsule 100 mg every 12 hours. Intervention 3: The third group will receive clonidine tablet 0.4-1.2 mg per day in three subdivided doses according to the patient's tolerance, clonazepam tablet one mg per eight hours, acetaminophen tablet 500 mg every six hour, and dextromethorphane 75 mg every six hours. Intervention 4: The fourth group will receive clonidine tablet 0.4-1.2 mg per day in three subdivided doses according to the patient's tolerance, clonazepam tablet one mg per eight hours, amantadine capsule 100 mg every 12 hours and dextromethorphane 75 mg every six hours.