Opioids Major Depressants Opiates Opioids The History of Opiates

Major Depressants • Opiates/Opioids: Opioids • Used to treat acute pain, diarrhea, coughs, etc. • Abused for their euphoric effects, for physical & emotional pain relief, & for suppression of withdrawal symptoms • Sedative-hypnotics: • Are synthesized drugs devised to treat anxiety & insomnia • All have toxic side effects & can cause tissue dependence • Alcohol: • Produced by fermentation of plant sugars or starches • It is the oldest psychoactive drug in the world • Is the second most destructive drug in terms of health consequences & social consequences Opiates/ Opioids • Some of the oldest & best documented psychoactive drugs • Opium is processed from a milky fluid of the opium poppy plant that is processed to morphine, codeine, etc • Semisynthetic opiates include heroin & prescription painkillers like OxyContin, & Vicodin The History of Opiates • 6000 years ago: Beginning of opium use • 1806: German Frederick Serturner isolated active ingredient in opium - Morphine • 1832: Isolated codeine • 1874: Heroin developed as a derivative of morphine by C.R. Alder Wright • 1898: Heroin used a treatment for coughs, tuberculosis, & bronchitis, in place of codeine • 1924: Congress amended the Smoking Opium Act to include heroin • 1970’s: Schedule I drug— illegal for any medical use Administration • Oral ingestion: • Opium originally chewed, eaten, or drunk Effects of Opioids • Used legally to control pain, coughing, & diarrhea • Used illegally to induce a rush & euphoria, to control emotional pain, & to avoid withdrawal symptoms • Smoking Opium: • Increased nonmedical use & intensity of effects, & multiplied abuse potential • IV Use: • Refinement of morphine, codeine, & heroin which increased the strength factor of 10 • Morphine & heroin injected thus increasing the intensity & addictive potential especially with heroin • Snorting: • More than half of all heroin addicts entering treatment began their use by insufflation 1 Effects of Opioids • Pain: • Opioids prevent transmission of substance “P”, the neurotransmitter that transmits pain • They also block most of what does get through to the receiving neuron • Painkilling effects are similar including lowered anxiety, serenity, drowsiness, & deadening of unwanted emotions • The variables: the strength & toxicity of the drug and the duration of use Effects of Opioids • Pleasure: • Opioids artificially active the reward/reinforcement center by slotting into receptor sites meant for endorphins • Heroin has the strongest effect of all opioids on the reward pathway • Opioids disrupt the cut-off switch in the brain that say’s “that’s enough” Effects of Opioids • Receptor sites: • Many natural opioid receptor sites for the body’s endogenous opioids • The drugs slot into these same receptors with each opioid drug having a unique affinity for each kind of opioid receptor site Pharmacological Effects of Opioids • Suppress coughs by controlling the cough center in brainstem • Control diarrhea by inhibiting gastric secretions & depressing intestinal muscles • Sense of expanded intellect • Temporarily lower body temperature • Only cardiovascular effect is a dilation of peripheral blood vessels leading to a flushed, warm feeling Pharmacological Effects of Morphine • Induces a dreamlike euphoria • Induces vomiting • Morphine & codeine suppress the “cough center” in brainstem • Most important peripheral effect is constipation • • • • • • • • • Side Effects of Opioids • Physical effects: Felt in every part of the body Drooping eyelids, nodding, & slurred slowed speech Nausea Constipation Cough suppression Respiratory depression Pinpoint pupils Coma Tolerance & physical dependence can develop 2 Tolerance, Tissue Dependence, Withdrawal The desire for relief from pain & experiencing of pleasure combined with tolerance, tissue dependence, & withdrawal are the main reasons for the addictive nature of opioids Tolerance • Occurs when tries to neutralize the heroin by variety of methods • Includes: • • • • Speeding up metabolism Desensitizing nerve cells Excreting the drug more rapidly Altering the brain & body chemistry to compensate for the effects of the drug • Tolerance develops at different rates & there’s no limit to development of opioid tolerance Tissue Dependence • The adaptation to effects of the drug can alter brain chemistry temporarily & sometimes permanently • The body relies on the drug to stay normal since cessation of use causes severe withdrawal symptoms • Tolerance & physical dependence can extend to other opioids Withdrawal • Acute withdrawal: • Occurs when 2-3 weeks of continuous use are followed by abstinence • Protracted withdrawal: • Can last for months after abstinence has begun • Short-acting opioids: • (heroin & morphine) cause more severe acute withdrawal symptoms • Long-acting opioids: • (methadone) delay withdrawal & acute symptoms are milder but last for weeks Additional Problems with Opioids • Neonatal effects: • • • • • • • Occur because opioids cross the placental barrier Increased risk of miscarriage Placental separation Premature labor Stillbirth Seizures Baby born to an addicted mother is also addicted & withdrawal for an infant is severe to fatal Additional Problems with Opioids • Overdose: • in older users can be fatal • Severe respiratory depression is major cause of death with heroin overdose • Overdose can be countered by opioid antagonist, but will cause severe withdrawal effects to addicts 3 Additional Problems with Opioids • Dirty & shared needles: • One of greatest dangers of drug use since large, potentially fatal doses can enter the bloodstream & the risk of adulteration of the drug is high • Bacteria & viral infection, including HIV, can be transmitted by dirty needles • Hepatitis C & HIV: – 50%-90% of all needle-using heroin addicts have hepatitis C – 25% of U.S. AIDS cases were transmitter by IV users Additional Problems with Opioids • Abscesses & other infections: • Common among IV users • Can destroy subcutaneous tissue but is not immediately visible on surface • Endocarditis- infection of heart valves • Cotton fever- caused by endotoxins in cotton that are used to prepare drug injections Additional Problems with Opioids • Dilution & adulteration: • Street drugs can vary radically in purity & be adulterate with a variety of potentially dangerous chemicals Additional Problems with Opioids • Cost: • Heroin is expensive • $20-$200 per day depending on level of use • 60% of the cost to support the habit is gotten through consensual crime • 73% of heroin users are gainfully employed Additional Problems with Opioids • From experimentation to addiction: • Starts with alcohol, marijuana, & tobacco much earlier than heroin • Takes average of one year of sporadic heroin use to develop a daily habit • Over time, pain relief offered by heroin use becomes greater that the pleasure • Treatment is a physiological as well as a psychological process • Relapse often due to fear of withdrawal symptoms Additional Problems with Opioids • From experimentation to addiction: – The Vietnam experience: • Suggests that even though tissue dependence caused by use of drugs is basis for addiction, heredity & environment of returnees seemed to have an even greater influence on whether they remained addicted 4 Morphine • Refined from opium and is the standard by which effective pain relief is measured. • Different routes of administration have different effects. • Liver is principle site of metabolism • Can be detected in urine for several days Morphine • Therapeutic Pain control: • Concerns are fear of addiction might develop, that the opioid will mask the clues to a serious disease, & the patient may fake symptoms to supply habit • Most of the problems with moderate-strength opioids come from long-term use • The body becomes more sensitive to pain because the body produces fewer of its own painkillers Codeine • Extracted directly from opium or refined from morphine • It’s an analgesic & used to control severe coughs • Used to be the most widely prescribed & abused prescription opioid In USA until hydrocodone (Vicodin) • Half-life is 3 hours & is detectable in urine for 2-3 days Hydrocodone (Vicodin) • Most prescribed opioid • It has many of the same actions as codeine but produces less nausea Oxycodone (OxyContin) • Much stronger than codeine but weaker than morphine • OxyContin is the timerelease version of the drug • When crushed, the time-release effect is destroyed making the drug potent and similar effect to heroin Designer heroin • Includes street versions of fentanyl (China White) • These drugs are made without controls & can be very dangerous since they are 100-20,000 times stronger than regular heroin • Can contain MPTP that destroys dopamine-producing brain cells • Causes the condition “frozen addict” 5