title: Glucocorticoid negative feedback in methadone-maintained former heroin addicts with ongoing cocaine dependence: dose-response to dexamethasone suppression.
abstract: Combined cocaine and illicit opiate use is common. This study aimed to test the hypothesis that cocaine dependence in former heroin-addicted patients maintained on methadone treatment is associated with enhanced glucocorticoid negative feedback. Multiple dose dexamethasone suppression tests, using a conventional 2.0 mg dose, and two lower doses, 0.5 mg and 0.125 mg, were performed in 10 methadone-maintained former heroin addicts with ongoing cocaine dependence (C-MM), 10 stabilized methadone-maintained former heroin addicts with no ongoing drug or alcohol use (MM), and 22 normal volunteers (NV). At 9 hours, there was no difference in plasma adrenocorticotropin hormone (ACTH) and/or cortisol levels among groups on the baseline day, as well as after the two lower doses of dexamethasone. At 17 hours, C-MM and MM had significantly lower plasma ACTH and/or cortisol levels than NV. However, C-MM did not significantly differ from MM in their hormonal levels. When the hormonal responses to dexamethasone are expressed as magnitude of lowering from baseline, there was no significant difference at any dose among groups. Therefore, C-MM exhibited a normal glucocorticoid negative feedback in the morning. Using the standard interpretation of dexamethasone suppression testing based on the examination of the actual hormonal levels rather than the difference from baseline condition, C-MM appear to have glucocorticoid effects similar to MM, yet were both greater than NV in the late afternoon. Thus, further studies are needed to know whether altered glucocorticoid negative feedback is related to chronic cocaine exposure, or is the result of former heroin addiction and/or its long-term treatment with methadone.
authors.affiliation: Laboratory of Pathophysiology of Behavior, The Victor Segalen's University (Bordeaux 2), France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Aouizerate
authors.forename: Ann
authors.initials: A
authors.lastname: Ho
authors.forename: James H
authors.initials: JH
authors.lastname: Schluger
authors.forename: Guillaume
authors.initials: G
authors.lastname: Perret
authors.forename: Lisa
authors.initials: L
authors.lastname: Borg
authors.forename: Michel
authors.initials: M
authors.lastname: Le Moal
authors.forename: Pier V
authors.initials: PV
authors.lastname: Piazza
authors.forename: Mary Jeanne
authors.initials: MJ
authors.lastname: Kreek
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology; D019970:Cocaine-Related Disorders / Q000503:physiopathology* / Q000534:rehabilitation; D015897:Comorbidity; D003907:Dexamethasone; D004305:Dose-Response Relationship, Drug; D005246:Feedback / Q000502:physiology*; D005260:Female; D005938:Glucocorticoids / Q000502:physiology*; D006556:Heroin Dependence / Q000503:physiopathology* / Q000534:rehabilitation*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D008691:Methadone / Q000627:therapeutic use*; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000503:physiopathology; D012016:Reference Values
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D008691:Methadone; D006854:Hydrocortisone