Stimulants - I: Cocaine 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

Psychoactive Compounds

Compounds that excite or enhance psychomotor activity 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 Freebase 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

Cocaine Structure

Mode of Action on CNS a and b adrenergic receptors activated 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

Action of cocaine on CNS

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