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Medication Assisted Therapy for Opioid Addiction: Methadone and Buprenorphine Andrew J. Saxon, M.D. Veterans Affairs Puget Sound Health Care System and University of Washington Seattle, WA Disclosures Supported by: National Institute on Drug Abuse Clinical Trials Network Scientific Advisory Board, Alkermes, Inc. Speaker, ReckittBenckiser, Inc. Medication Assisted Treatment • Methadone and Buprenorphine – Pharmacology – Efficacy • Starting Treatment with Agonist Replacement Therapies (START) Study – Comparing methadone and buprenorphine on • Treatment retention • Illicit opioid use • HIV risk reduction Methadone Pharmacokinetics and Dosing • Rapidly absorbed • Peak Levels in 4 hours • t1/2=24 hours • Metabolized in liver (p450 3A/4) • Doses should be individualized but higher doses generally more effective Kyle et al., 1999 Swedish Methadone Study Experimental Group (Methadone) Gunne & Gronbladh, 1981 Before Control Group (No Methadone) Swedish Methadone Study Experimental Group (Methadone) After 2 Years Control Group (No Methadone) a b c d d d Gunne & Gronbladh, 1981 a b c d Sepsis Sepsis and Endocarditis Leg Amputation In Prison Methadone Side Effects • Minimal sedation once tolerance achieved • Constipation • Increased Appetite/Weight Gain • Lowered Libido; May decrease gonadal hormone levels • Exhaustively studied in all other organ systems with no evidence of chronic harm Properties of Buprenorphine, a µ-Opioid Partial Agonist Ceiling effect on respiratory depression High affinity for µ-opioid receptor Slowly dissociates from µ-opioid receptors Ameliorates withdrawal once underway Can precipitate withdrawal if given in temporal proximity to full agonist opioids Efficacy: Full Agonist (Methadone) Partial Agonist (Buprenorphine), Antagonist (Naloxone) 100 Full Agonist (Methadone) 90 80 70 % 60 Efficacy 50 Partial Agonist (Buprenorphine) 40 30 20 Antagonist (Naloxone) 10 0 -10 -9 -8 -7 Log Dose of Opioid -6 -5 -4 Buprenorphine Pharmacology Poor oral bioavailability; given sublingually (subcutaneous implants: experimental; patch: for pain) Slow onset (Peak effects 3-6 hrs.) Long duration (24 - 48 hours) Slow offset Half life > 24 hours Zubieta et al., 2000 Buprenorphine Maintenance vs. Detoxification No. Assessed for Eligibility: 84 All Patients: No. Excluded: 44 Not Meeting Inclusion Criteria: 41 Group CBT Relapse Prevention Weekly Individual Counseling Refused to Participate: Three times Weekly Urine Screens No. Randomized: 40 Other Reasons: 2 1 Allocated to Buprenorphine: 20 Allocated to Detox/placebo: 20 Received Buprenorphine: 20 Received Detox/Placebo:20 Included in Analysis: Included in Analysis*: Excluded from Analysis: 20 0 Excluded from Analysis: 20 0 Kakko J et al. 1-year retention and social function after buprenorphine-assisted relapse prevention treatment for heroin dependence in Sweden: a randomized, placebo-controlled trial. Lancet 361(9358):662-8, 2003. Remaining in treatment (nr) Maintenance vs. Detoxification: Retention 20 15 10 Detox/placebo 5 Buprenorphine 0 0 50 100 150 200 250 Treatment duration (days) 300 350 Maintenance vs. Detoxification: Mortality Detox/Placebo Buprenorphine Cox regression Dead 4/20 (20%) 0/20 (0%) c2=5.9; p=0.015 Kakko J et al. 1-year retention and social function after buprenorphine-assisted relapse prevention treatment for heroin dependence in Sweden: a randomized, placebo-controlled trial. Lancet 361(9358):662-8, 2003. Buprenorphine Implants for Opioid Addiction Ling et al., 2010 START Study Schema 1920 Number screened for participation 1269 740 Buprenorphine/Naloxone 340 Evaluable 400 Failed to remain on assigned medication for 24 wks 0 Failed to provide ≥ 4 LT samples 261 Completed 32-week follow-up Randomized 529 Methadone 391 Evaluable 136 Failed to remain on assigned medication for 24 wks 2 Failed to provide ≥ 4 LT samples 330 Completed 32-week follow-up Treatment Retention Survival Curves for Buprenorphine Versus Methadone Buprenorphine (n=738) 1 Methadone (n=529) 0.6 0.4 0.2 168 160 140 120 100 80 60 40 20 0 0 Survival 0.8 Days in treatment during 24 weeks 1 Treatment Retention by Dose Comparing Retention at 24 Weeks by Maximum Dose of Medication Prescribed 0-40 mg methadone (max) 41-60 61-80 81-120 100% 121+ 17.0% 23.4% 35.6% % of completion 80% 60% 40% 20% 15.3% 8.7% 27.9% 26.8% 27.6% 5.8% 11.8% 0% 0-10 12-14 16-20 22-28 mg buprenorphine (max) 30-32 Buprenorphine (% = % of buprenorphine participants prescribed in that dose range) Methadone (% = % of methadone participants prescribed in that dose range) Opiate Positives by Dose Average Weekly Dose and Positive Opiate over Weeks in Treatment (n=1,267) Buprenorphine dose (n=738) Opiate positive among BUP patients Methadone dose (n=529) Opiate positive among MET patients 100 80 60 40 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 0 Week in Treatment HIV Injection Risk Behavior Risk Behavior Survey completed at baseline, week 12, week 24 Needle Sharing in Past 30 Days among Week 24 Completers: Baseline (%) Week 24 (%) p Bup/Nx (n=340) 14.4 2.4 <.0001 MET (n=391) 14.1 4.8 <.0001 HIV Sexual Risk Behavior Risk Behavior Survey completed at baseline, week 12, week 24 Multiple Sexual Partners in Past 30 Days among Week 24 Completers: Baseline (%) Week 24 (%) p Bup/Nx (n=340) 6.8 5.2 <.04 MET (n=391) 8.2 5.1 <.04 MAT for Opioid Addiction Methadone and Buprenorphine Conclusions Relapse rates are high without MAT Methadone and Buprenorphine both efficacious and reduce mortality Methadone and Buprenorphine both reduce HIV risk behaviors