Psychoactive Plants

1. Psychoactive Plants Stimulants - I: Cocaine

2. 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

3. 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

4. Psychoactive Compounds

5. Stimulants Compounds that excite or enhance psychomotor activity

6. Cocaine • Most powerful natural stimulant • Major alkaloid in the coca plant • Erythroxylum coca • Erythroxylum novogranatense • Small trees in genus Erythroxylum (Family Erythroxylaceae) native to Andes Mts in South America • Alkaloid found in leaves – leaves have been used (chewed) by native peoples of the Andes for thousands of years

8. Cocaine use among the Incas • Incas considered coca plant sacred – casual chewing not allowed • Chewing coca leaves only by royalty and priests and also permitted for endurance by soldiers, runners, workers and the sick • Coca leaves also used for trade • Commonly added ashes when chewing which adds CaCO3 to release cocaine • By the time the Spanish arrived coca chewing was part of everyday life – but not abused

9. Spanish Conquest • Incan Empire was enormous prior to the Spanish Conquest – stretched through much of S. America – 10 million people • Pizarro and army conquered Incas easily in 1533 • Native populations enslaved and forced to work in the mines – conditions were very harsh and millions died • Initially they prohibited coca use until they realized its potential – productivity and endurance increased when slaves were given coca leaves to chew • Spanish rule was unbearable – by 1650 the population had fallen to 4 million

10. Introduction to Europe • Initially no interest because the leaves lost potency during long journey • By mid 19th century, coca wine was becoming popular - Vin Mariani • In late 1850s alkaloid cocaine isolated from the leaves • Anesthetic properties soon put to use in medicine • Stimulating properties soon brought “fame” • In the 1880s Freud helped increase “fame” by prescribing it to patients and using it himself

11. Cocaine in US – 19th century • By late 19th century, cocaine use was wide spread in over-the-counter medications, tonics, and beverages • Used for colds, asthma, and hay fever because it helps shrink mucous membranes and drain sinuses • Coca-cola developed in 1886 and marketed as a “brain tonic” Coca-cola was promoted as a temperance drink "offering the virtues of coca without the vices of alcohol". • Harrison Act of 1914 regulated use of cocaine along with opium, morphine, and heroin

14. Late 20th to 21st centuries • Still has limited use as an anesthetic for certain types of surgery – many uses replaced by Novacain and Xylocaine • Cocaine abuse sharply increased starting in mid 1970s and 1980s • Freebasing and crack, increased the chances of addiction to cocaine • Although cocaine was initially viewed as harmless, cocaine related deaths have made us realize it is an especially deadly drug

15. Source of cocaine • Colombia remains the world's leading producer of cocaine • Three-quarters of the world's annual yield of cocaine is produced there, both from cocaine base imported from Peru and Bolivia and from locally grown coca • Various attempts at control - herbicides, fungal pathogens

18. Forms of Cocaine • Cocaine hydrochloride • Hydrochloride salt, or powdered form of cocaine, dissolves in water • Can be taken snorted (intranasally) or dissolved in water and 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 • Freebase is smoked

19. Crack • Smoking crack delivers large quantities of cocaine to the lungs • Produces effects comparable to intravenous injection • The effects are felt almost immediately after smoking, are very intense but do not last long

20. Cocaine Structure

21. Mode of Action on CNS • Neural system that appears to be most affected originates in a region, deep within the brain, called the ventral tegmental area • Nerve cells originating there extend to the nucleus accumbens, (one of reward center) • 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 • Also blocks reuptake of norepinephrine

22. Action of cocaine on CNS

24. Effects of Cocaine • Increased energy • Decreased appetite • Mental alertness • Increased heart rate and blood pressure • Constricted blood vessels • Dilated pupils • Increased temperature

25. 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

26. Addiction • Because of the powerful high, cocaine is one of the most psychologically addictive substances known • In contrast to heroin, no antidote and no clinically useful antagonist is available to treat cocaine addiction • Some unique approaches are being tried experimentally including development of a cocaine "vaccine"

27. Tolerance • An appreciable tolerance to the high may developed • Many addicts report that they seek but fail to achieve as much pleasure as they did from their first exposure

28. Cardiovascular Effects • Cocaine causes the heart to beat more rapidly and blood vessels to constrict • This results in the demand for a greater supply of blood • But the narrowed blood vessels are unable to deliver the volume of blood demanded, which significantly increases the risk of cardiovascular incidents or strokes

29. Negative health effects of use • In rare instances, sudden death can occur on the first use of cocaine or subsequent uses • However, there is no way to determine who is prone to sudden death • Deaths result from cardiac arrest, stroke, cerebral hemorrhage or seizures, followed by respiratory arrest • Prolonged snorting can result in ulceration of the mucous membrane of the nose and can cause nasal septum to collapse

30. Crack users • Evidence suggests that users who smoke or inject cocaine may be at even greater risk than those who snort it • Cocaine smokers suffer from acute respiratory problems including coughing, shortness of breath, and severe chest pains with lung trauma and bleeding.

31. Direct effects on heart • Recent study suggest that cocaine works directly on the heart - not the arteries as previously thought - to trigger the high blood pressure and heart attacks • Sinus node of heart may be directly stimulated by cocaine and may cause heart to beat faster and contract harder • Each year >165,000 cocaine users brought to U.S. hospital emergency rooms

33. Negative psychological effects • Some users report feelings of restlessness, irritability, and anxiety - high doses and/or prolonged use can trigger paranoia. • Smoking crack can produce a particularly aggressive paranoid behavior in users • When addicted individuals stop using cocaine, they often become depressed • This also may lead to further cocaine use to alleviate depression