OPIOIDS I. Where do they come from? • poppy plant: from middle east and Asia • dried sap from plant isopium; cultivated annually BUT plant produces drug within only 10 day window over 87% of world’s opium comes from Afghanistan (2005 U.N. report) • major active ingredient in opium: morphine / synthesized in 1803 / named after the Greek god of dreams Morpheus / morphine altered in late 1800s into heroin - a “heroic” TX (3-10x as strong as morphine) / Fentanyl
OPIOIDS Other names they go by? - Oxycodone - Codeine: Lean; Purple stuff (cough syrup with sprite and jolly ranchers) - others? ______________
OPIOIDS II. Medical Uses • As pain reliever (morphine, demerol, codeine, lortab, lorcet, percodan, percocet, vicodin, oxycontin) • with chronic pain or terminal patients • in some cough suppressants • treatment of diarrhea, which is dehydrating
OPIOIDS III. Prevalence Heroin compared to non-medical use of rx Pain meds: Lifetime Past Year Current 2004: H: 1.3% 0.2% 0.1% P: 13.2% 4.7% 1.8% - new heroin users may smoke, sniff or snort it rather than inject……why ?
OPIOIDS IV. Mechanisms of action • opiates triggerour own brain chemicals, the endorphins (short for “endogenous morphine”) to relieve pain • naloxone ____________ effects of opiates by blocking opiate receptor sites
OPIOIDS V. Effects • produces short-lived euphoria, profound relaxation, body warmth (lowers body temp) • tolerance develops rapidly so increasing doses is very common • drug taking becomes a chore to avoid withdrawal SX - illustrates ? reinforcement
Rats: heroin tolerant Received injection of heroin 15 mg/kg in familiar environment Overdose rate: % Rats: heroin tolerant Received injection of heroin 15 mg/kg in unfamiliar environment Overdose rate: % Control rats: No heroin tolerance Received injection of heroin 15 mg/kg for first time Overdoserate: % A diagram of Siegel’s rat experiment
OPIOID WITHDRAWAL • Stoppage (or reduction] in opioid use that has been heavy and prolonged (several weeks +) • OR administration of opioid antagonist after period of use • Symptoms include: (need at least 3 for DSM criteria) • dysphoric mood - yawning • diarrhea - fever • muscle aches - dilation of pupils, piloerection • insomnia or sweating • nausea or vomiting • runny eyes or nose
OPIOIDS VI. Treatment • methadone TX: peak concentration occurs 2-4 hours after taken, in contrast to effects of other opiates which kick in right away like a hammerblow; metabolites of methadone are inactive, unlike other narcotics • blood levels of methadone, when given orally, is below ED level in tolerant patients, and is safely above the threshold for withdrawal...so, methadone combines safety and long action - LAAM, naltrexone, buprenorphine - TCs
OPIOIDS - Controversy • Needle exchange programs to prevent HIV: are you pro/con? • Should heroin be given to terminal patients? Do terminal patients have right to die with drugs? • Should non-terminal pain patients be freely medicated with morphine or even stronger painkillers?
Prescription Opioid Abuse Historical Aspects 1990 - Current • Through the efforts of pain control advocates, organized medicine, scientific journals, & malpractice suits, prescribing opiates for pain became more common during the last decade of the 20th Century • Opioid therapy became accepted (although often inadequately) for treating acute pain, pain due to cancer, & pain caused by a terminal disease • Still disputed is the use of opioids for chronic pain not associated with terminal disease
Evolving Landscape of Drugs of Abuse Farming Pharming 13
Potential subpopulations of prescription Opioid Abusers • Persons who abuse or are dependent on only prescription opioids • Abusers of other opioids, e.g., heroin, when they cannot get their drug of choice • Polydrug abusers • Pain patients who develop abuse or dependence problems on these drugs in the course of legitimate medical treatment
Why Has the Abuse of Prescription Drugs Been Increasing? • Increasing numbers of prescriptions • Others?
As Prescriptions Increase, ER Reports Have Increased at the Same or Faster Rate 24000 80000 . Hydrocodone 70000 prescriptions 18000 emergency 60000 50000 ED Mentions Number of Prescriptions (in 1000s) 12000 40000 Oxycodone 30000 prescriptions 6000 emergency 20000 10000 0 0 1994 1995 1996 1997 1998 1999 2000 2001 Source: IMS Health for Prescriptions and SAMHSA (DAWN) for Emergency Department Mentions