Stimulants

1. Stimulants

2. Stimulants • Stimulants are chemical substances that stimulate the brain and the central nervous system. • They cause increased alertness and wakefulness. In many cases they also act to decrease appetite. • Amphetamines, nicotine and caffeine are all examples of stimulants.

3. Neurotransmitters • Neurotransmitters work to transmit electrical neuro-impulses across a synapse. • Many stimulants enhance the neuro-impulse transmission systems L dopamine Serotonin

4. Stimulants The structures of many stimulants are closely related to the structures of neurotransmitters in the body. L Dopamine Serotonin Methamphetamine

5. Amphetamines • Amphetamine was first marketed in the 1930s as Benzedrine, an over-the-counter inhaler to treat nasal congestion. • Used for (1) Narcolepsy- a sleeping disorder (2) Attention Deficit Hyperactivity Disorder (ADHD) (3) During World War II, amphetamines were used to keep the fighting men alert especially under intense battle conditions.

6. Amphetamines Amphetamines closely mimic the chemical structure and effects of adrenalin (epinephrine) and are known as sympathomimetic drugs.

7. Amphetamines Amphetamines • constrict arteries, increase perspiration activity, and stimulate brain activity. • increase heart rate and blood pressure. • increase wakefulness, restlessness, agitation and insomnia.

8. Amphetamines • Amphetamines became a cure-all for helping long haul truckers stay awake • Also used for weight control, for helping athletes to perform better and train longer • Intravenous amphetamine abuse • Evident that the dangers of abuse outweighed therapeutic uses.

9. Ecstasy Ecstasy is a powerful stimulant that has some characteristics in common with adrenalin and L-dopamine as well Attempts to synthesize new amphetamines led to so called designer drugs, all of which are highly dangerous

10. Harmful effects of amphetamines • highly addictive and toxic • Their long term use leads to deterioration of a number of body systems. • Chronic abuse produces a psychosis that resembles schizophrenia and is characterized by paranoia, picking at the skin, preoccupation with one's own thoughts, and auditory and visual hallucinations. • Severe depression and violent or erratic behavior are also common among meth addicts.

11. Nicotine • Found in tobacco • Vasoconstrictor • Increases blood pressure • Highly addictive Nicotine is an example of an alkaloid. Alkaloids are found in plant material. They are characterized by a heterocyclic nitrogen ring structure.

12. Nicotine • Increases level of fatty acids in the blood stream • Increases stomach acidity and the incidence of peptic ulcers. • Highly toxic

13. Short term effects of nicotine • Nicotine increases heart rate, blood pressure and constricts the blood vessels. • This puts stress on the heart since it is forced to pump blood harder than normal. • This accounts for the greater long-term incidence of heart problems for smokers.

14. Tobacco smoke In addition to nicotine, there are a variety of hazardous substances that have been identified in tobacco smoke

15. Nicotine and Tobacco Smoking In addition to nicotine, poisonous tobacco smoke also results in (1) Reduced oxygen in the blood due to a high concentration of CO (2) Increased exposure to several carcinogens

16. Nicotine and Tobacco Smoking Tobacco smoking is associated with the increased risk of (1) lung cancer (2) emphysema (3) cancer of the larynx and mouth (4) heart disease (5)chronic bronchitis

17. It is much easier to become dependent on nicotine than on alcohol or barbiturates. • Nicotine produces psychological dependence and builds up tolerance. • Many heavy smokers experience physical dependence as well. People who give up smoking can experience withdrawal symptoms such as weight gain, nausea, insomnia, irritability, fatigue, inability to concentrate as well as depression and a craving for cigarettes.

18. Caffeine • Caffeine is a mild stimulant and a weak diuretic. • It is found in coffee, tea and some other beverages

19. Caffeine Caffeine • stimulates the central nervous system • increases the rates of cellular metabolism.

20. Caffeine is a heterocyclic compound in which one or more carbon atoms in the ring are replaced by another atom, nitrogen. • Like nicotine it contains a tertiary amine group - in which three organic substituents are attached to nitrogen, fitting the general formula R3N

21. Caffeine • Caffeine stimulates the central nervous system heart, kidneys, lungs and arteries • Increases blood supply to the heart and brain. • Enhances alertness, well being motivation, and concentration.

22. Caffeine • In small amounts caffeine is considered relatively harmless. • Stimulates respiration • Vasoconstrictor - potential use in the treatment of migraines.

23. Effects of Caffeine • In large quantities it may cause sleeplessness. • Prolonged consumption may lead to tolerance but no physical addiction

24. Theobromine • Found in chocolate. • Similar effects to caffeine • Only structural difference is the methyl group on the six member heterocyclic ring.