Buprenorphine for Pain and for Addiction David A. Moltz, MD MAPP Clinical Conference April 30, 2010 I. Addiction and Dependence DSM IV Substance Dependence A maladaptive pattern of substance use, with 3 or more of: • Tolerance • Withdrawal • Using larger amounts or for a longer time than intended • Persistent desire or lack of control • A great deal of time spent obtaining, using, recovering from • Important activities given up • Continued use in spite of negative consequences Addiction A chronic but treatable brain disease characterized by loss of control compulsive use use despite known harm relapse Dependence vs Addiction • Addiction may occur with or without the presence of physical dependence. • Physical dependence results from the body’s adaptation to a drug or medication and is defined by the presence of – Tolerance and/or – Withdrawal Opioid Use in a Household Survey Population • According to the 2002 National Survey on Drug Use and Health : An estimated 4.4 million persons were current users of pain relievers for nonmedical purposes. • New non-medical pain reliever use more than quadrupled from 1990 (628,000 new users) to 2000 (2.7 million new users). SOURCE: SAMHSA, 2002. Neural circuitry of reward Present in all animals Produces pleasure for behaviors needed for survival: Eating Drinking Sex Nurturing Neural circuitry of reward Altruism activates the same circuitry Meeks TW, Jeste DV. The neurobiology of wisdom. Arch Gen Psychiatry 2009;66(4):355-365 Addiction is not a disease of the synapses alone --Mark Publicker II. Properties of Buprenorphine Definition of Terms • Agonist • Antagonist • Affinity • Intrinsic Activity • Dissociation Buprenorphine Novel opioid with both agonist and antagonist properties Partial agonist at mu opioid receptor High affinity Low intrinsic activity Slow dissociation Antagonist at kappa receptor Buprenorphine • High affinity for mu receptors ability to compete with full mu agonists (such as heroin) and to block their effects. • Low intrinsic activity feeling of wellbeing without full opioid effects • Very slow dissociation rate prolonged therapeutic effects. • Ceiling effect Opiate Potency of Methadone, LAAM, and Buprenorphine Slide courtesy of Laura McNicholas, MD, PhD, Univ of Penn. 100 90 80 70 % 60 Efficacy 50 40 30 20 10 0 Full Agonist (Methadone) Partial Agonist (Buprenorphine Antagonist (Naloxone) -10 -9 -8 -7 Log Dose of Opioid -6 -5 -4 Blockade Effect • Buprenorphine has tight binding to and slow dissociation from opioid receptors. It produces a blockade effect at the mu-opioid receptor so that subsequently administered opioids do not produce their full euphoric effect. • It appears to produce less physical dependence than a full opioid agonist (such as methadone), and it may be easier to discontinue at the end of medication treatment. Advantages of a Partial Agonist • Lower abuse potential • Lower level of physical dependence • Relative safety if ingested in overdose quantities • Weak opioid effects compared with methadone. Severity of Opioid-Withdrawal Symptoms after Abrupt Discontinuation of Equivalent Doses of Heroin, Buprenorphine, and Methadone Kosten T and O'Connor P. N Engl J Med 2003;348:1786-1795 Kappa antagonism • In animal models of depression, dynorphins (kappa agonists) increased stress. • Kappa antagonists relieve it. • “Blockade of k-opioid receptors may have therapeutic potential for the treatment of depression.” Shirayama Y, et al. Stress increases dynorphin immunoreactivity in limbic brain regions and dynorphin antagonism produces antidepressant-like effects. J Neurochemistry 2004;90: 1258-68 III. Buprenorphine for Addiction Drug Addiction Treatment Act of 2000 (DATA 2000) • Expands treatment options to include both the general health care system and opioid treatment programs. – Expands number of available treatment slots – Allows opioid treatment in office settings – Sets physician qualifications for prescribing the medication Beneficial Effects Blocks craving Blocks opiate withdrawal Does not produce a ‘high’ Blocks the effects of other opioids Milder withdrawal than methadone Stabilization of brain function Anti-depressant / anti-anxiety effect Beneficial Effects Significant enhancement in treatment retention and in the quality of participation Mainstreaming of opioid dependence treatment with office-based practice Greater safety Lower diversion risk Beneficial Effects • Buprenorphine is as effective as moderate doses of methadone. • Partial agonist effects make it mildly reinforcing, encouraging medication compliance. • After a year of buprenorphine + counseling, 75% of patients were retained in treatment compared to 0% in a placebo + counseling condition. Cognitive Effects • Available evidence in patients maintained on buprenorphine indicates no clinically significant disruption in cognitive and psychomotor performance. • “Long-term use…does not impair driving ability.” Dagtekin O, et al. Assessing cognitive & psychomotor performance under long-term treatment with transdermal buprenorphine in chronic noncancer pain patients. Anesth Analg 2007;105:1442-8 Suboxone • Buprenorphine + naloxone • Partial agonist + pure antagonist • Naloxone is only active intravenously • Will precipitate withdrawal in opioid-dependent individuals • Combination decreases diversion risk IV. Buprenorphine and Pain Pain Patients vs Addicted Persons Risk Factors • Psychosocial • Genetic • Drug-related Pseudo-addiction • “Drug-seeking behavior” • Consequence of inadequate treatment of pain • May be indistinguishable from addictive behavior Effectiveness in Pain • • • • 30-40 times more potent than morphine Ceiling effect high safety profile Transdermal used extensively in Europe “…transdermal buprenorphine provides effective, sustained and dose-dependent analgesia, irrespective of age.” Pergolizzi J et al. Opioids & the management of chronic severe pain in the elderly: Consensus statement of an international expert panel. Pain Practice 2008;8(4):287-313 Chronic Cancer Pain • Transdermal buprenorphine vs. sustainedrelease morphine, with tramadol supplementation. • “The administration of transdermal buprenorphine versus morphine resulted in significant differences in the physical pain (p=0.01), mental health (p=0.03) and vitality (p=0.001).” Pace, MC, et al. Buprenorphine in long-term control of chronic pain in cancer patients. Frontiers in Bioscience 2007;(12):1291-1299 Post-Partum Pain • Women stabilized on methadone or buprenorphine, treated post-partum with opioids or ibuprofen as needed. • Buprenorphine group decreased ibuprofen use over 5 days. • Methadone group increased ibuprofen use. Jones HE, et al. Management of acute postpartum pain in patients maintained on methadone or buprenorphine during pregnancy. Am J Drug and Alcohol Abuse, 2009; 35:151-56 Neuropathic Pain • • • • 30 patients with chronic painful neuropathy Transdermal buprenorphine Non-blinded study 40% had clinically meaningful pain relief Penza P, et al. Short- and intermediate-term efficacy of buprenorphine TDS in chronic painful neuropathies. J of the Peripheral Nervous System 2008;13:283-288 Managing Pain During Buprenorphine Maintenance • Supplement with NSAIDS • Temporarily replace buprenorphine with opiates • Override buprenorphine with opiates • Divide +/or increase buprenorphine dose Heit HA, Gourlay DL. Buprenorphine: New tricks with an old molecule for pain management. Clin J Pain 2008; 24(2):93-97 Hyperalgesia Hyperalgesia • A decrease in the threshold to elicit pain • A state of nociceptive sensitization • Hyperesthesia Allodynia The generation of pain in response to lowintensity stimuli or stimuli that are not normally painful. Mechanisms of Hyperalgesia • NMDA (glutaminergic) • Dynorphin (kappa receptor agonist) • Peripheral, spinal and central sensitization • “More complexity than clarity” Opioid-Induced Hyperalgesia • May be activation of hyperalgesic systems to counteract the analgesic effects of the opioids • Ex: Morphine activates NMDA receptors and spinal dynorphin • In withdrawal, the hyperalgesic system is unopposed Hyperalgesia and Tolerance • May share mechanisms (eg,NMDA), but they are clinically different • Hyperalgesia is increased sensitivity to pain • Tolerance is decreased sensitivity to opioids Chang G, et al. Opioid tolerance & hyperalgesia. Med Clin N Am 2007;91;199-211 OIH and Tolerance • Difficult to differentiate clinically • OIH diffuse, generalized pain, often different from pre-existing pain • Stopping the opioid can differentiate – Tolerance more pain – OIH less pain Treating OIH • Minimize opioid dose using adjuvant therapies • Opioid rotation • Methadone (NMDA antagonist) • Buprenorphine Pain reduction after detoxification • 23 patients not getting benefit from highdose opioids • No addictive behaviors • 21 showed marked decrease in pain after detoxification • After weaning, 63% decrease in pain with buprenorphine vs. 47% without Baron MJ, McDonald PW. Significant pain reduction in chronic pain patients after detoxification from high-dose opioids. J Opioid Management 2006;2(5):277-282 Neuropathic pain • Buprenorphine relieves allodynia from neuropathic pain • Blocks hyperalgesia due to central hypersensitization • Kappa antagonist (blocks dynorphin) • “Buprenorphine has been shown to have a pronounced antihyperalgesic effect.” Induru RR, Davis MP. Buprenorphine for neuropathic pain – Targeting hyperalgesia. Am J Hospice & Palliative Med 2009:26 (6);470-3 Likar R. Transdermal buprenorphine in the management of persistent pain – Safety aspects. Therapeutics & Clinical Risk Management 2006:2(1):115-125 Buprenorphine and OIH • “Resolution of OIH usually follows quickly during the maintenance phase with buprenorphine.” • “Buprenorphine may be unique in its ability to treat chronic pain and possibly OIH” Silverman SM. Opioid induced hyperalgesia: Clinical implications for the pain practitioner. Prescription Opioid Addiction Treatment Study (POATS) • Opioid dependence • 42% with co-existent chronic pain • Overall, 49% substantially improved after 3 mo of buprenorphine • Of those with chronic pain, 53% substantially improved, and “many had significant improvement in their pain.” Weiss R. NIDA Blending Conference 4/22/10. www.NIDA.NIH.Gov Coexistent Addiction and Pain • Buprenorphine is ideal • Treats addiction • Treats pain • Relieves hyperalgesia Resources • Clinical Guidelines for the Use of Buprenorphine in the Treatment of Opioid Addiction. SAMHSA/CSAT Treatment Improvement Protocols. TIP 40. • http://buprenorphine.samhsa.gov • http://www2.aaap.org/buprenorphine (For DATA training)