Medicines and drugs

1. Medicines and drugs Depressants

2. depressants • depress the central nervous system (brain and spinal chord); change communication between brain cells by altering the activity of neurotransmitters. This causes a decrease in brain activity.

3. Terminology Depression – clinical condition characterized by mood changes and loss of interest in normal activities. The drugs used to treat depression are called antidepressants.

4. Effects of depressants

5. Short term physiological effects of ethanol abuse • reduces tension, anxiety and inhibitions • May become happy and outgoing • Flushed face due to dilated blood vessels • May become distracted or angry • impairs function of central nervous system • Slurred speech • Memory loss • Loss of balance/judgment • Vomit – can lead to aspiration • Dehydration due to increased urination • High doses - Loss of consciousness, coma, death

6. Long term physiological effects of ethanol abuse • liver damage/cancer • Cirrhosis (normal liver tissue is replaced by scar tissue and liver stops working properly) • increased blood pressure • heart disease or stroke • dementia • miscarriage and fetal abnormalities • Brain damage • tolerance and physical dependence

7. Social effect of ethanol use/abuse • increased risk when driving or operating machinery • involvement in violence or crime • relationship problems • taking time off work as a result of sickness or death associated with alcohol abuse • loss of income • hospital costs

8. Synergetic effect of ethanol with other drugs Ethanol produces a synergic effect with other drugs (their effect is enhanced in the presence of alcohol) which can be dangerous Ex. With aspirin it can increase damage to stomach and cause increased bleeding. In the case of sleeping tablets and other sedatives it can increase sedation, or cause coma or death.

9. How to detect ethanol 1. Potassium dichromate (VI) – The breathalyzer • Only used for detection in breath • In a positive result (i.e. presence of alcohol) the potassium dichromate changes form orange to green when ethanol is present as the potassium dichromate is reduced and the ethanol oxidized to ethanoic acid. • Equations • oxidation: C2H5OH + H2O → CH3CHO + CH3COOH (ethanal + carbox acid) • reduction: Cr2O72−+ 14H+ +6e− → 2Cr3+ + 7H2O

10. How to detect ethanol 2/3. GLC – Gas-Liquid Chromatography • Used for blood and urine samples • Ethanol is separated from the urine or blood using gas-liquid chromatography • Produces a chromatograph which shows how much ethanol is in your system • Most accurate of the 5

11. How to detect ethanol 4. Intoximeter – IR Spectroscopy • Used for breath, blood and urine. • Infrared radiation is passed through breath, blood or urine. The C–H bond in ethanol causes radiation to be absorbed at a specific wavelength which is 2950 cm -1. • The intoximeter measures the amount of absorption which depends upon the amount of ethanol in the breath i.e. the more ethanol there is present the more IR is absorbed. The amount or peak is compared against a standard (e.g. allowed amount).

12. How to detect ethanol 5. Intoximeter – Fuel Cell • Used for breath • Ethanol is oxidized in the air to ethanoic acid and then to CO2 and H2O • The energy released in this reaction is converted into a detectable electrical voltage to measure ethanol concentration.

13. Other commonly used depressants Anti- depressant Sleeping pills And muscle relaxants

14. Other commonly used depressants Amide Tertiary amine C- has no H’s ( is sp2 - HL) Differences

15. Other commonly used depressants • All reduce stress/insomnia • All can lead to dependence • Only treat symptoms and should be used short term until other treatments (therapy, etc) help the cause of the problem