Add-on Low Dose Dextromethorphan and Memantine in Patients With Amphetamine-type Stimulants Use Disorder

The Potential Therapeutic Effects of add-on Low Dose Dextromethorphan and Memantine in Patients With Amphetamine-type Stimulants Use Disorder

The current study will investigate whether add-on dextromethorphan (DM) and memantine (MM) is able to improve the treatment outcomes for ATSUD, and be associated with improvement in inflammatory markers, neurotrophic factors and neuropsychological tests.

In current study, we will conduct a randomized double-blind placebo-controlled study. We will recruit 100-120 patients with ATSUD in three years and allocate them to add-on low dose dextromethorphan and memantine (DM 30mg/day+MM 5mg/day) or placebo group in a 1: 1 ratio (patients will also undergo usual psychosocial interventions). We will follow up the participants for 12 weeks and measure the treatment responses, urine drug tests, craving scales and side effects to evaluate the therapeutic effects of add-on DM+MM. Neuropsychological assessments and tests for inflammatory parameters and neurotrophic factors will also be measured during 12-weeks follow up. The study results will show that whether add-on DM+MM is able to improve the treatment outcomes for ATSUD, and be associated with improvement in inflammatory markers, neurotrophic factors and neuropsychological tests.

Inclusion Criteria:

Patients must meet all of these inclusion criteria to be eligible for enrollment into the study:

1. Signed informed consent by patient or legal representative.
2. Male or female patient aged ≧20 and ≦65 years.
3. A diagnosis of ATSUD according to DSM criteria made by a specialist in psychiatry.
4. Patient or a reliable caregiver can be expected to ensure acceptable compliance and visit attendance for the duration of the study.

Exclusion Criteria:

The presence of any of the following will exclude a patient from study enrollment:

1. Women of childbearing potential, not using adequate contraception as per investigator judgment or not willing to comply with contraception for the duration of the study.
2. Females who are pregnant or lactation.
3. Other major Axis-I DSM-IV diagnosis other than ATSUD, except for tobacco use disorder, ATS induced mood or psychotic disorders.
4. Current evidence of an uncontrolled and/or clinically significant medical condition, e.g., cardiac, hepatic and renal failure that would compromise patient safety or preclude study participation.
5. History of allergy or intolerable side effects of DM or MM.
6. Suicidal attempts or risks during screen or study period.
7. Presence of active infectious or autoimmune disease.