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Psychoactive Plants. Stimulants - I: Cocaine. Psychoactive Plants. Psychoactive plants act on the central nervous system - often by influencing neurotransmitters or endorphins Can be divided into three categories Stimulants – excite or enhance psychomotor activity (caffeine, cocaine)
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Psychoactive Plants Stimulants - I: Cocaine
Psychoactive Plants • Psychoactive plants act on the central nervous system - often by influencing neurotransmitters or endorphins • Can be divided into three categories • Stimulants – excite or enhance psychomotor activity (caffeine, cocaine) • Depressants – reduce mental and physical performance (opiates, alcohol, kava) • Hallucinogens – induce a dreamlike state and hallucinations (peyote, marijuana, morning glory seeds) • May also be narcotic
Narcotic Compounds • By definition a narcotic drug induces central nervous system depression resulting in numbness, lethargy, sleep • In current use, a narcotic is a psychoactive drug that is dangerously addictive • Addictive compounds elicit: psychological dependence, physiological dependence, and/or tolerance
Stimulants Compounds that excite or enhance psychomotor activity
Cocaine • Major alkaloid in the coca plant • Erythroxylum coca • Erythroxylum novogranatense • Small trees in genus Erythroxylum (Family Erythroxylaceae) native to Andes Mts. in South America
Ethnobotany and history • Cocaine use by the Incas • Spanish conquest • Introduction to Europe • US – 19th century • Late 20th and 21st centuries • Sources of cocaine
Forms of Cocaine • Cocaine hydrochloride • Hydrochloride salt, or powdered form of cocaine, dissolves in water • Can be taken snorted or taken intravenously • Freebase • Compound that has not been neutralized by an acid to make the hydrochloride • Hydrochloride is heated with water and sodium bicarbonate to form crack which is usually smoked
Mode of Action on CNS • Region most affected - deep within the brain (ventral tegmental area) • Nerve cells originating there extend to the nucleus accumbens (one of the reward centers) • At the synaptic level, cocaine blocks the re-uptake of dopamine results in a build up of dopamine in the synapse which contributes to the high - later dopamine is depleted • Blocks reuptake of norepinephrine • a and b adrenergic receptors activated
Effects of Cocaine • Increased energy • Decreased appetite • Mental alertness • Increased heart rate and blood pressure • Constricted blood vessels • Dilated pupils • Increased temperature
Highs from cocaine • Duration of cocaine's euphoric effects depends on the route of administration • The faster the absorption, the more intense the high BUT the faster the absorption, the shorter the duration of action • High from snorting may last 15 to 30 minutes, while that from smoking may last 5 to 10 minutes (high from smoking starts in 10 sec) • Increased use can reduce the period of stimulation
Negative effects of cocaine use • Addiction • Tolerance • Cardiovascular effects • Direct effects on the heart • Respiratory problems • Psychological effects