Inclusion Criteria:

1. Male or female opioid-dependent outpatient aged 18 years or older,
2. Women of childbearing potential must have a negative urine pregnancy test result at the Inclusion Visit (test under supervision of the investigator or designee),
3. Women of childbearing potential must use an effective birth control method. Women of non-childbearing potential must be postmenopausal or must be surgically sterile (hysterectomy and/or bilateral oophorectomy),
4. On buprenorphine (Subutex® or generic buprenorphine) maintenance therapy at a minimum daily dose of 2 mg for at least 3 months prior to inclusion,
5. Declaring buprenorphine intravenous misuse at least four times/week and showing needle marks,
6. Willing to stop or reduce buprenorphine intravenous misuse,
7. Having received oral and written information about the trial, and provided written informed consent prior to admission to this trial.

Exclusion Criteria:

1. Pregnancy or breast-feeding,
2. Contraindication or history of hypersensitivity to buprenorphine, naloxone or to any excipient of Suboxone® or Subutex®,
3. Any medical or psychiatric condition which in the opinion of the investigator would make participation difficult or unsafe,
4. Participating in another trial,
5. Patients in the exclusion period of the "Fichier National des personnes qui se prêtent à des recherches biomédicales" (National Index of persons participating in biomedical researches, or National Index of volunteers).