OPIOIDS I. Where do they come from? –poppy plant: from middle east and Asia –dried sap from plant is opium; cultivated annually BUT plant produces drug within only 10 day window 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 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 1998: heroin + non-medical use of analgesics –Lifetime- 6.4% Past Year- 2%Current-.9% 2001: H: 1.4% 0.2% 0.1% P: 9.8%3.7%1.6% current users: # significantly increasing it was estimated that there were 141,000 new users of heroin in rate of new heroin users increasing; 90% are under age 26 and smoke, sniff or snort it rather than inject……stigma? - DAWN data: 14% of all drug-related episodes involve heroin

OPIOIDS IV. Mechanisms of action opiates trigger our own brain chemicals, the endorphins (short for “endogenous morphine”) to relieve pain naloxone reverses and blocks 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 to opiates so increasing doses is very common drug taking becomes a chore to avoid withdrawal SX - illustrates ? reinforcement

Rats: heroin tolerant Control rats: No heroin tolerance Received injection of heroin 15 mg/kg in familiar environment Received injection of heroin 15 mg/kg in unfamiliar environment Received injection of heroin 15 mg/kg for first time Overdose rate: 32% Overdose rate: 64% Overdose rate: 96% To some degree, drug tolerance is associated with environmental factors. Tolerance may disappear or decrease if a drug is used in an unfamiliar environment. 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 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?

OPIOIDS Morphine treatment for pain generally given to 2 groups of patients: –post-surgery patients receive it on short-term basis –cancer and burn victims given it for much longer durations (typically given IM or under the skin) What about potential for addiction?