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Barrera ED, Loughlin L, Greenberger S, Ewing S, Ranaldi R, Ranaldi R. Environmental enrichment reduces heroin seeking following incubation of craving in both male and female rats. Drug Alcohol Depend 2021; 226:108852. [PMID: 34225225 PMCID: PMC8355213 DOI: 10.1016/j.drugalcdep.2021.108852] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/24/2021] [Accepted: 05/01/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Contemporary treatments for heroin use disorder demonstrate only limited efficacy when the goals are long term abstinence and prevention of relapse. We have demonstrated that environmental enrichment (EE) reduces cue-induced heroin reinstatement in male rats. The present study is an attempt to extend the "anti-relapse" effects of EE to female rats and to periods where incubation of craving is hypothesized to occur. METHODS This experiment implemented a 3-phase procedure. In Phase 1, male and female rats were trained to self-administer heroin for 15 days. Phase 2 consisted of a 3- or 15-day forced abstinence (FA) period. In Phase 3 half of the rats were placed into EE and the other half in non-EE housing and subsequently tested for responding in extinction (no heroin or cues) for 15 days followed by a cue-induced reinstatement test. RESULTS We found that rats in the 15 days FA condition showed significantly enhanced drug seeking during extinction, irrespective of sex. We also found that EE significantly reduced this effect. During reinstatement, EE significantly reduced drug seeking in male and female rats and in both 3- and 15-day FA groups. CONCLUSIONS EE, with or without prolonged FA, effectively reduced heroin seeking in male and female rats. These findings indicate that EE can reduce drug-seeking in males and females and when putative incubation of craving (i.e., prolonged abstinence period) has occurred and suggest that it may aid in the development of future long-term behavioral treatments for individuals at risk for heroin relapse.
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Affiliation(s)
| | | | | | | | - Robert Ranaldi
- Department of Psychology, Queens College, the City University of New York, Flushing, NY, United States.
| | - Robert Ranaldi
- Department of Psychology, Queens College, the City University of New York, Flushing, NY, United States.
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The Use of the Methadone/Metabolite Ratio (MMR) to Identify an Individual Metabolic Phenotype and Assess Risks of Poor Response and Adverse Effects: Towards Scientific Methadone Dosing. J Addict Med 2021; 14:431-436. [PMID: 32032212 DOI: 10.1097/adm.0000000000000620] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVES Significant genetic variability of metabolism confounds reliable clinical use of methadone because physicians have no way of identifying individual patient metabolism. The methadone/metabolite ratio (MMR), the numerical ratio of serum methadone to its inactive metabolite ethylidine-dimethyl-diphenypyrrolidine (EDDP), represents the net expression of the genes controlling metabolism. The MMR has been adapted to four established pharmacogenetic metabolic categories: ultra-rapid (URM), extensive (EM, normal), intermediate (IM), and ultra-slow (USM). METHODS This study reports on the analysis of 1700 paired peak and trough serum samples for methadone and EDDP. The MMR data were stratified by metabolic category. The reliability of these categories and the relationship of the MMR to 2 other laboratory assessments, a peak/trough ratio (PTR) and a methadone half-life, was tested. Additionally, peak and trough serum levels were analyzed by MMR category. RESULTS Each category of MMR identified significantly different mean serum levels (peak and trough), peak/trough ratios, and half-lives. When serum levels were analyzed, evidence of subtherapeutic serum levels were found, predominantly in the URM and EM categories. Seventeen percent of peak serum levels were greater than 1000 ng (a level indicating potential toxicity) with a range up to 2384 ng, predominantly in the IM and USM categories. CONCLUSIONS The MMR measures an individual's phenotype for methadone metabolism. The data suggested underdosing in the URM category, as well as evidence of excessive dosing in IM and USM categories. The MMR provides a guide to safe and effective dosing, an alternative to the pharmacokinetically 'blind' dosing algorithms currently in use.
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Chalabianloo F, Fadnes LT, Høiseth G, Ohldieck C, Vold JH, Aas C, Løberg EM, Johansson KA, Bramness JG. Subjective symptoms and serum methadone concentrations: what should guide dose adjustments in methadone maintenance treatment? A naturalistic cohort study from Norway. SUBSTANCE ABUSE TREATMENT PREVENTION AND POLICY 2021; 16:39. [PMID: 33941217 PMCID: PMC8091668 DOI: 10.1186/s13011-021-00367-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 03/23/2021] [Indexed: 05/11/2023]
Abstract
BACKGROUND There is little evidence-based guidance on how to optimize methadone dosages among patients with opioid addiction undergoing methadone maintenance treatment (MMT). This study aims to investigate whether self-perceived opioid withdrawal symptoms, adverse effects, and self-reported substance use in patients on MMT are related to serum methadone concentrations and the role that these variables could play in clinical decisions on dose adjustments. METHODS This naturalistic prospective cohort study included clinical and laboratory measurements from 83 patients undergoing MMT in outpatient clinics in Bergen, Norway, from May 2017 to January 2020. Information on age, gender, methadone daily doses and serum concentrations, subjective opioid withdrawal symptoms using 16 items Subjective Opioid Withdrawal Scale (SOWS) questionnaire, self-reported adverse effects, and substance use was obtained. Linear mixed modelling was used for analyzing the data. RESULTS The mean age of the participants was 45 years, and 33% were women. Almost half reported mild to moderate subjective opioid withdrawal symptoms, and all had experienced at least one subjective adverse effect. The use of at least one substance was reported by 88% of the participants. Serum concentration-to-dose ratios were lower among those who had reported subjective opioid withdrawal symptoms (p) = 0.039). The total SOWS score (p < 0.001); the specific subjective withdrawal symptoms of anxiety (p = 0.004), bone and muscle aches (p = 0.003), restlessness (p = 0.017), and (slightly) shaking (p = 0.046), also use of heroin (p = 0.015) and alcohol (p = 0.011) were associated with lower methadone concentrations. Cannabis use was slightly related to higher methadone concentrations (p = 0.049). CONCLUSIONS The findings suggest that the patient's self-perceived symptoms and current clinical condition are related to the serum concentrations of methadone. This interpretation supports dose adjustments based on patient-reported symptoms. In some aberrant cases, measurement of serum concentrations together with other individual assessments may be considered to support the clinical decision.
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Affiliation(s)
- Fatemeh Chalabianloo
- Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway. .,Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
| | - Lars Thore Fadnes
- Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Gudrun Høiseth
- Department of Forensic Medicine, Oslo University Hospital, Oslo, Norway.,Center for Psychopharmacology, Diakonhjemmet Hospital, Oslo, Norway.,Norwegian Center for Addiction Research, University of Oslo, Oslo, Norway
| | - Christian Ohldieck
- Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway
| | - Jørn Henrik Vold
- Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Christer Aas
- Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Else-Marie Løberg
- Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway.,Institute of Clinical Psychology, University of Bergen, Bergen, Norway.,Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Kjell Arne Johansson
- Department of Addiction Medicine, Haukeland University Hospital, Bergen, Norway.,Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Jørgen G Bramness
- Institute of Clinical Medicine, UiT - Norway's Arctic University, Tromsø, Norway.,Department of Alcohol, Tobacco and Drugs, Norwegian Institute of Public Health, Oslo, Norway
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