Desvenlafaxine in Opioid-Dependent Patients

To assess the feasibility, tolerability and acceptability of 8 weeks of Desvenlafaxine (DESV) administration among opioid-dependent subjects in a methadone-maintenance program, we will collect detailed information on compliance to DESV treatment, side effects, methadone plasma levels, methadone dose changes and QTc measures.

To explore the effects of DESV on depressive symptoms among opioid-dependent subjects on methadone-maintenance treatment. The severity and symptoms of depression will be evaluated by using the MADRS, the HRDS, and the CGI scale.

To explore the effects of DESV on substance use, anxiety, craving, quality of life and suicidal risk.

Inclusion criteria

• DSM-IV-TR criteria for opioid dependence;
• Subject is on methadone treatment in the substitution program for at least 4 weeks;
• Subject is aged between 18 and 65 years old;
• subject meets the DSM-V TR criteria for major depressive episode, according to the study psychiatrist and confirmed by the Mini International Neuropsychiatric Interview (MINI);
• Subject reports a score of 20 or higher on the MADRS;
• Subject is eligible for and consents to the study;
• subject is able to give valid, informed consent;
• subject is able to speak and read French or English (grade-nine level of language required)

Exclusion criteria

• Unstable medical illness, defined as any medical illness which has not been well-controlled with standard-of-care medications;
• Severe psychiatric condition (e.g., current acute psychosis, past or current hypomania/mania) based on the MINI;
• Pregnancy or breastfeeding;
• Inability to use a medically acceptable form of contraception throughout the study duration. A medically acceptable form of contraception is either: (1) contraceptive pill or intrauterine device or depot hormonal preparation (ring, injection, implant); and/or (2) a barrier method of contraception such as diaphragm, sponge with spermicide or condom;
• Subject currently takes another antidepressant;
• Treatment with Desvenlafaxine at any time in the past;
• Known hypersensitivity to venlafaxine;
• Subject is undergoing psychotherapies for current depression (support therapy or counseling are allowed);
• Subject failed to respond to two or more Health-Canada-approved antidepressants during current episode;
• Unstable Axis-II personality disorder or other Axis-II disorder which has been the primary focus of treatment in the past 3 months, as ascertained by a study psychiatrists;
• Medical diagnosis of kidney and/or liver failure