IRCT20090801002266N16 IRCT 2022-02-09 Esfahan University of Medical Sciences Amantadine in methamphetamine-dependent patients The assessment of amantadine add-on therapy effects on craving and relapse reduction among patients with methamphetamine dependence. 2022-03-01 anticipated 64 Complete https://irct.ir/trial/56393 interventional Randomization: Randomized, Blinding: Triple blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: After selection, eligible participants are randomly divided (by Block Design Randomization method) into two groups of amantadine and placebo, for both groups a 2-month matrix treatment plan is considered and then will be followed for 4 months, Blinding description: The patients, the Psychiatry resident who is responsible for the project, the statistician, and the person who supervises the project process are blinded to the categorization of the patients into drug versus placebo groups. 2-3 Craving and relapse reduction in methamphetamine-dependent patients. Intervention 1: Intervention group: The intervention group will be treated with a daily dose of 100 mg amantadine capsules (Hakim, Iran) that will be increased by 100 mg every week to achieve the maximum daily dose of 300 mg (100 mg every 8 hours); if tolerated by the patients. The matrix program will be performed for two months with the latest dose and by the end of the program, the medication will be ceased. In case who cannot tolerate the maximum dose, the medication will be performed by the highest tolerable dose. The patients will be assessed using urine methamphetamine and other drugs tests weekly during the program and then, monthly in the follow-up period. Intervention 2: Control group: The control group will be intervened with a capsule made by the Pharmacy faculty similar to the amantadine. They will administer the medication for two months. The assessments are similar to the intervention group that will be weekly during the matrix program period and then, monthly in the follow-up period using urine methamphetamine and other drugs urine test. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is Research Institue limitation policies