Opioid Dependence: Highlighting Buprenorphine Treatment Tony Tommasello, Pharmacist, PhD Associate Professor UM School of Pharmacy Office of Substance Abuse Studies 515 West Lombard Street – 263 410 706-7513 atommase@rx.umaryland.edu Learning Objectives At the conclusion of this program participants will be better able to: * 1. Describe the forces that are driving the current increase in opioid abuse in the U.S. * 2. Explain the need for non-pharmacological interventions for addicted patients * 3. List therapeutic outcomes for addiction treatment * 4. Distinguish medical withdrawal and medical maintenance * 5. Explain the pharmacological basis for medical maintenance * 6. Describe differences between methadone, buprenorphine, and naltrexone pharmacotherapy * 7. List policy changes relative to opioid addiction treatment in America Dynamics of a Heroin Epidemic Number of US Narcotic Analgesic-Related ED Visits, 1994-2001 Teen Abuse of Rx Drugs: National Figures Access to Treatment Is Limited * Of the estimated 810,000 opioid-dependent persons in the United States, only 170,000 maintenance treatment slots exist Aspects of Addiction The Memory of Drugs Opioid Addiction: Effects on the Body * Opioids activate receptors in the central nervous system (CNS) and the gastrointestinal (GI) track * CNS stimulation provides pleasurable feelings while GI stimulation produces constipation * Other CNS effects include miosis, respiratory depression, drop in blood pressure Why Treatment? * Dysfunctional lifestyle of opioid addiction makes treatment a desired alternative * Oral methadone and buprenorphine sublingual tablets are approved for both medical withdrawal and medical maintenance Addiction Treatment * Optimal treatment combines pharmacological and nonpharmacological therapies for successful management of those addictions for which pharmacotherapy has been approved (opioid, alcohol, nicotine) Primary Treatments Are Nonpharmacological * Individual and/or group cognitive behavioral therapy * Urine monitoring for drugs of abuse (also sweat, saliva, and blood) * Support group participation – Narcotics Anonymous – Alcoholics Anonymous Patient Response to Addiction Treatment Will Vary * Patient characteristics—age, employment experiences, concurrent illnesses, family support * Patient history—past treatment experiences, duration and level of drug use * Patient motivation * Length of time in treatment Opioid Addiction Pharmacotherapy Enhances Treatment Outcomes * Medical Withdrawal: Remove the opioid from the body and remain free of future opioid use * Maintenance Therapy: Use a substitute opioid (agonist), “satisfy narcotic hunger,” eliminate craving * Buprenorphine approved for both approaches Pharmacology of Opioids * Affinity: The strength with which a drug binds to its receptor * Dissociation: The speed at which a drug uncouples from its receptor * Efficacy: The percent of maximal response that a drug generates when it binds to the receptor Full Agonists * Bind to and activate receptor site * As dose is increased, effect is increased until a maximum response is attained * Examples: – Heroin – Oxycodone – Methadone Antagonists * Bind to the receptor without causing activity * An antagonist can block the receptor from being activated by partial or full agonist * Examples: – Naloxone – Naltrexone Partial Agonists * Bind to receptor and excite the receptor * Activity reaches a plateau at which an increase in dose does not result in increased activity * Examples: – Buprenorphine (also a kappa antagonist) – Pentazocine Comparative Efficacies Pharmacokinetic Distinctions Methadone * Slowly absorbed from the gut reaching peak blood level in 45 to 90 minutes * Half-life in maintenance patient is 24 hours * Allows once-daily dosing Buprenorphine * Sublingual tablets must be held under the tongue for 4 to 8 minutes for absorption * Peak blood level in 60 minutes * Half-life is 32 hours * Allows once-daily or every-other-day dosing Other Distinctions * Buprenorphine has greater opioid receptor affinity and slower receptor dissociation than methadone * Buprenorphine will displace a full agonist (methadone) and dock at the receptor, thus blocking other full agonists from attaching there * Patients switching from methadone to buprenorphine may experience withdrawal distress and are advised to complete a reduction process before starting buprenorphine Buprenorphine/Naloxone Combination and Buprenorphine Alone * Two dosages: – Buprenorphine 2 mg with naloxone 0.5 mg – Buprenorphine 8 mg with naloxone 2 mg * Two dosages: – Buprenorphine 2 mg – Buprenorphine 8 mg Medical Withdrawal With Buprenorphine * Opioid-dependent individuals are treated with the goal of achieving a smooth transition to being substance free in a short period of time * Dose-tapering patients should be engaged in counseling and have counseling continued after medical withdrawal is complete * MDs and pharmacists should continue to reinforce to patients the importance of counseling after withdrawal Induction Dosing Guidelines: Buprenorphine for Non-Methadone Patients * Give the first dose after discontinuing opioids and some withdrawal symptoms are evident * Precipitated withdrawal is avoided by giving the first dose of buprenorphine after withdrawal symptoms are displayed Titrate to Stability Staging and Grading Systems of Opioid Withdrawal (TIP 40) Signs of Opioid Intoxication and Overdose (TIP 40) * Opioid Intoxication – Conscious – Sedated, drowsy – Slurred speech – “Nodding” or intermittently dozing – Memory impairment – Mood normal to euphoric – Pupillary constriction * Opioid Overdose – Unconscious – Pinpoint pupils – Slow, shallow respirations; respirations below 10 per minute – Pulse rate below 40 per minute – Overdose triad: apnea, coma, pinpoint pupils (with terminal anoxia: fixed and dilated pupils) Medical Withdrawal Dosing: Buprenorphine for Non-Methadone Patients * A maximum dose of 8 mg can be administered on the first day as Subutex® or as Suboxone® * Patients who still have withdrawal distress should be treated symptomatically and have their doses increased to a maximum of 16 mg for Day 2 * Stabilize for 2 days before tapering, then taper 2 mg/day every 2 to 3 days Model: Prescription Medical Withdrawal Medical Withdrawal “Withdrawal services are essentially acute services with short-term outcomes, whereas heroin dependence is a chronic relapsing condition, and positive long-term outcomes are more often associated with longer participation in treatment.” Medical Withdrawal * Overemphasis on the importance of being drug free * Underestimates the challenges associated with addiction * Nonpharmacological interventions are critical to recovery success Sustaining Abstinence * Naltrexone (Trexan) 50 mg/day is used to prevent opioid effects if a patient uses opioids during recovery – Patient must be narcotic free 7 to 10 days before starting therapy – Naltrexone “blocks” heroin high and other effects – Noncompliance and low patient acceptance Maintenance Treatment * Patients consume a long-acting prescription opioid medication as a substitute for the illegal short-acting street opioid * “The most dramatic effect of this treatment has been the disappearance of narcotic hunger” Outcomes of Treatment * Methadone is the standard pharmacotherapy for opioid addiction * Two outcomes for treatment – Reduction of illicit opioid abuse – Retention in treatment * Medical maintenance is the best treatment option in achieving these outcomes Buprenorphine Trials Data (Retention) Buprenorphine Trials Data (Opioid Abuse) Buprenorphine Trials Data (Urine Tests) Model Prescription Maintenance Treatment Clinical Trials Dosing * Sublingual buprenorphine daily doses of 8 to16 mg has been shown to be equally effective to oral methadone daily doses of 80 to 120 mg * Buprenorphine maintenance is ideal for people abusing illegal opiates and for those who want to switch from methadone to buprenorphine * Protocols for treatment can be found in the manual Clinical Guidelines for the Use of Buprenorphine in the Treatment of Opioid Addiction: a Treatment Improvement Protocol (TIP) 40. Available at: www.samhsa.gov/centers/csat/csat.html Drug Interactions * Benzodiazepines—respiratory depression and cardiovascular collapse are possible when high doses are taken of both drugs. Patients must be closely monitored * Other depressants produce additive effects on the CNS and may create interactive effects for patients operating motor vehicles or heavy machinery * Buprenorphine given to tolerant physically dependent opiate addicts may produce withdrawal symptoms * Buprenorphine is metabolized by the cytochrome p450 3A4 pathway. Drugs metabolized by the same pathway could result in higher than normal levels of either drug. Patients who are on both buprenorphine and one of these drugs need to be monitored closely DATA (Drug Addiction Treatment Act) New Policy—New Practice Provisions of DATA * An amendment to the Controlled Substances Act * Allows certain physicians to prescribe and dispense for up to 30 patients Schedule III, IV, and V narcotic drugs that have been approved by the Food and Drug Administration for use in maintenance or detoxification treatment * An authorized physician, one year after his or her initial notification, may petition to increase up to 100 the number of patients s/he will treat* Authorized Buprenorphine Prescribers in the United States * http://buprenorphine.samhsa.gov/ * Physician locator selection provides map. Click on your state for physician listing List of Drugs Approved by FDA for Use Under DATA * Only buprenorphine formulated for sublingual use has been approved * Approved on October 8, 2002 * Two formulations, Subutex® and Suboxone® are available * No other medications are approved for use under DATA Expanded Access to Care * One public health goal is to make opioid addiction treatment available on demand * Methadone treatment clinics are operating at full capacity * The Drug Addiction Treatment Act, if widely implemented, will offer numerous points of entry into opioid addiction treatment Pharmacists’ Roles * Case finding through screening * Dispense buprenorphine sublingual tablets in accordance with the law * Patient education on proper sublingual use * Counsel patients regarding drug interactions * Advise counseling interventions and help patients locate appropriate therapists * Manage refill regularity Code of Federal Regulation Title 42 Part 2 * Protects the confidentiality of alcohol and drug abuse patients and their medical records * Is different from HIPAA * Restricts disclosure of patient information and any patient identifying information * Requires consent for ANY information to be disclosed Practice Implications * Pharmacists need to practice diligence when counseling patients * Pharmacists need to train their staff on the importance of not disclosing information on a patient receiving treatment * Pharmacists must limit the information they provide to others Initial Reports Are Favorable* * Pharmacists involved in early trials with buprenorphine sublingual pharmacotherapy generally found the experience to be clinically rewarding * Few expressed concerns about dangers associated with this treatment of opioid addiction Summary * Buprenorphine–effective pharmacotherapy for opioid addiction * Knowledgeable pharmacists can effectively counsel patients undergoing treatment with this medication * Pharmacists will be increasingly expected to dispense buprenorphine prescriptions and provide associated services Opioid Dependence: Highlighting Buprenorphine Treatment Tony Tommasello, Pharmacist, PhD Associate Professor UM School of Pharmacy Office of Substance Abuse Studies 515 West Lombard Street – 263 410 706-7513 atommase@rx.umaryland.edu