3/26/14. Opiates PSY B396 ALCOHOL, ALCOHOLISM, & DRUG ABUSE. Early History Cont d. Early History. Opiate Use in the 19th century. Technology Advances

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1 Opiates PSY B396 ALCOHOL, ALCOHOLISM, & DRUG ABUSE Chapter 10 Opiates The most dramatic example of the doubleedged sword character of drugs Most potent painkillers Prototype addictive drug: Heroin Early History The opium poppy, Papaver somniferum, is native to the Middle East Seed pod of the poppy secretes opium Cultivated 6,000 years ago Used medically in ancient Egypt, Greece, and Rome Analgesia Early History Cont d. Islam did not prohibit the use of opium Use spread by Arab traders to India and China China first tried to control opium use in 1729 Opiate Use in the 19th century A serious problem in China Opium was usually smoked Widespread medical use in Europe and USA Opium was usually ingested in liquid form, with fewer problems Recreational use in Europe and USA increased problems Technology Advances Sertürner isolates morphine (1803) Hypodermic needle allows injection of morphine (1850s) Treatment of pain from wounds was thereby improved Wounded soldiers became addicted to morphine: Soldier s disease 1

2 3/26/14 Technology Cont d. 1874: Wright invents diacetylmorphine 1898: Dreser finds that diacetylmorphine is twice as potent as morphine; names it heroin Marketed as a cough suppressant and pain reliever Opiate Use: 20th Century & Today 1914: Harrison Narcotics Act restricted opiates to medical use 1915: Only prescribe if doses were decreasing over time 1917: No prescriptions for addicts 1924: No prescriptions for heroin Subsequently, opiates move to the black market Change in Demographics Before 1914, opiates were used by all classes and across the country After 1914: Usage concentrated in cities Heroin the preferred opiate Organized crime involved Users were poor, young, poorly educated men Current Suppliers Afghanistan produces 80% of the world s supply Latin America provides most of US supply Colombia and Mexico Quality Control Street heroin is cut or adulterated Processing quality varies Criminal activity is involved Quality variations and mixtures of other drugs with heroin contribute to death by overdose IV Drug Use & Early Death Hser et al., 2001 study 581 heroin addicts total followed over 33 years 50% died 50 to 100 times general population death rate at the same age 20% still using 10% refused testing 14% in prison 2

3 Designer Heroin Illicit production, derivatives of the synthetic opiate fentanyl (China White) much more potent than heroin Errors in synthesis MPTP instead of MPPP Causes symptoms of Parkinson s Disease Many opiates are available Illicit use of prescription opiates has tripled from the 1990s to the present Use of prescription opiates in high school has increased Prescription Opiate Abuse Absorption GI Tract, nasal mucosa, and lungs Administration Oral, inhalation (smoking), intranasal (snorting) Injection: Subcutaneous (skinpopping), intramuscular, intravenous (mainlining) Distribution Distributed by blood supply, especially to GI tract, muscles, brain Heroin reaches the brain better than morphine In the brain, heroin becomes morphine Metabolism and Excretion Most opiates are metabolized in the liver Excretion is in urine 90% excreted within a day Traces detectable for 24 days Mechanisms of Action Discovery of endorphins: 1960s: Naloxone blocks morphine 1970s: Receptors for opiates 1975: Natural, morphinelike substances in the brain: endorphins, endogenous morphine Thus, opiates act on endorphin systems 3

4 3/26/14 What Do Endorphins Do? A natural pain relief system Acupuncture may activate endorphins Medical Use of Opiates Naloxone blocks acupuncture s pain relief Placebos may activate endorphins Naloxone blocks placebo pain relief Main use: Pain relief or analgesia Morphine is the comparison standard, with analgesia value of 1 Tolerance develops to the pain relief provided by opiates The greater potency of heroin could help terminal cancer pain Comparison of the Major Opiates Making Opiates Safer Combine opiates for pain relief with ultralow naltrexone, an opiate antagonist: Acute Effects Euphoria: Drowsiness, body warmth, heavy limbs Opiate abusers like the effects Reduced sexual interest in men and women; impotence in men Impaired social interaction Vivid dreamlike experiences: pipe dreams Enhances the pain relief Blocks rewarding effects Slows development of tolerance Reduces severity of withdrawal More Acute Effects Cognitive impairment Learning and memory Methadone maintenance clients Respiratory depression and lowered body temperature Nausea, vomiting, pinpoint pupils 4

5 Administration and Withdrawal Effects Chronic Effects Tolerance: Chronic users steadily increase the dose Withdrawal: Motivation for use switches from positive to negative reinforcement, to avoid withdrawal symptoms Withdrawal and Dependence First, 812 hours after last dose: Runny nose and eyes, sweats, irritability, tremor Later, peaking after 4872 hours: More severe early symptoms, plus Pupil dilation, anorexia, and piloerection (goosebumps) Treating Withdrawal No treatment: Cold turkey, Kicking the habit Any opiate drug Detoxification with methadone withdrawal High risk of relapse (90% within 6 months), especially on returning to the same environment Contact your Instructor with: Comments Questions Concerns Suggestions 5