Medicines and drugs Depressants

depressants depress the central nervous system; they calm and relax the nervous system as they slow down the action of the brain, heart and other organs.

Effects of depressants doseeffect lowmay exert little or no effect. moderatemay induce sedation, soothing, reduction of anxiety, impaired judgement highmay induce sleep, unconsciousness, slurred speech, altered perception extremely highmay cause organ failure, come or death

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 lower economical production

Short term physiological effects reduces tension, anxiety and inhibitions impairs function of central nervous system

Long term physiological effects liver damage/cancer cirrhosis increased blood pressure heart disease or stroke miscarriage and fetal abnormalities tolerance and physical dependence

Synergetic effect of ethanol with other drugs Ethanol produces a synergic effect with other drugs i.e. their effect is enhanced in the presence of alcohol which can be dangerous e.g. with aspirin it can increase damage to stomach and cause bleeding. In the case of sleeping tablets and other sedatives it can cause coma or death.

Using potassium dichromate Only used for detection in breath - breathalyzer. 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: C 2 H 5 OH + H 2 O → CH 3 COOH + 4H + + 4e − reduction: Cr 2 O 7 2 − + 14H + +6e − → 2Cr H 2 O

intoximeter 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. 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).

gas-liquid chromatography Used for blood and urine samples. Ethanol is separated from the urine or blood using gas-liquid chromatography Accurate as area underneath ‘ethanol’ peak in chromatogram indicates amount of ethanol in blood or urine.

Other commonly used depressants depressantstructure: functional groups Fluoxetine hydrochloride (Prozac®) aromatic benzene, ether, secondary amine, fluorine, chloride ion diazepam/Valium®;  amide/ketone/carbonyl;  (tertiary) amine; nitrazepam/Mogad on®;  amide/ketone/carbonyl;  (tertiary) amine;