PSYC 222 1st Edition Lecture 24Outline of Last Lecture • Benzodiazepines: Rohypnol• Nonbenzodiazepine hypnotics• Acute Toxicity• Patterns of abuse• Inhalants• Gaseous anesthestics• nitrites• volatile solvents• dangers of inhaling solvents• Gamma hydroxybutyric acidOutline of Current Lecture • Opioidsi. opioidsii. opium cultivationiii. history of opiumiv. morphinev. heroinvi. benefical usesvii. dependence potentialviii.opioid treatmentix. toxicity potentialCurrent Lecturei. Opioids can be divided into four broad categories: 1) 3 natural compounds that can be extracted from opium: morphine, codeine and thebaine. 2) Derivative compounds created by making specific changes in the chemical composition of morphine. 3) Derivative compounds created by making specific changes in the chemical composition of codeine or thebaine. 4) Compounds synthesized in the labaratory. Opium is a naturally occuring substance derived from the poppy plant. Papaver somniferum. Opiumhas a 6000 year history of medical use. Opioids are either: drugs derived directly from opium or synthetic drugs with opium-like effects. Major effects of opioids: relieves pain and suffering and delivers pleasure and relief and anxiety. ii. Opium is collected for only a few days of plant life. Opium harvesters make shallow cuts into the unripe seedpods. The resinous substance that oozes from the cuts is scraped. Opium products: morphine extracted from raw opium. Heroin is derived from morphine.iii. Egypt: 1500 BC: Ebers Papyrus described medical uses. Greece: had an important role in medicine. Arabic World: Opium used as a social drug. Physicians wrote widely about use of Opium and described opioid addiction. Europe: Opium used widely beginning in the 16th century. Physicians developed a preparation called laudanum, a combination of strained opium and other ingredients. Writers and Opium: 1821-Thomas De Quincy "Confessions of an English Opium-Eater". Elizabeth Barrett Browning and Samuel Taylor Coleridge famously used Opium. The Opium Wars- 1729: Opium smoking outlawed in China. But smuggling was widespread. British East India Company was involved in Opiumtrade. Legally in India and illicitly in China. Pressure grew and eventually war broke out between the British and Chinese.iv. Morphine is primary active ingredient in Opium. 1st isolated in 1806. Named Morphium after Morpheus, the god of dreams. 10 times as potent as opium. Codeine is a secondaryactive alkaloid. 1st isolated in 1832. Named codeine from Greek word "poppy head". Usespread due to 2 developments: 1) Technological development- 1853: Hypodermic syringe allowed delivery of morphine directly into the blood. 2) Political Development: widespread use during war provided relief from pain and dysentry. Veterans returned addicted to morphine. Addiction was later calleed "soldiers disease" or "army disease".v. Heroin- diacetylmorphine. 1874: 2 acetyl groups were attached to morphine. 1898: marketed as heroin by bayer. 3 times as potent as morphine. Due to increased lipid solubility of heroin molecules. Originally marketed as a non-addictive couch suppressant. Replacement for codeine and morphine. Later linked to addiction.vi. Pain Relief: 1) reduces the emotional response to pain. 2) diminshes the patients awareness of the aversive stimulus. 3) causes drowsiness, does not induce sleep. Treatment of intestinal disorders. Counteracts diarrhea and resulting dehydration. Decrease number of peristaltic contractions. Cough Suppresant; dextromethorphan is anopioid analoguevii. Tolerance: devlops to most effects. Higher doses needed to maintain effects. Cross tolerance exists among all the opioids. Physical Dependence: Opioid withdrawl is unpleasant but rarely life threatning. Withdrawl symptoms can be prevented with any opioid agonist. Psychological Dependence: positive reinforcement; positive effects reliably follow use of drug. Negative reinforcement; use of drug removes withdrawl symptoms. Fast acting injectable opioids are most likely to lead to dependence. viii.Using high doses of methadone is critical to its efficacy. Used either as a maintenence drug or as a drug that can be administered in smaller and smaller doses to reduce the addicts physical dependence on narcotics gradually. ix. Acute toxicity: Opioids depress respiration. Effects with alcohol are additive. Occasionallynausea and vomitting. can be counteracted with naloxone. Chronic Toxicity: associated with injection. Infections and spread blood borne