D4 Depressants

• The effects of depressants• Use and abuse of ethanol• Techniques used for detection of ethanol in urine and blood• Synergistic effects of ethanol and other drugs• Prozac, valium, mogadon• Described as antidepressants since they relieve

depression

The effects of depressants• The central nervous system is depressed by

interfering of the nerve impulses in the neurons (nerve cells)

• Slows down the functions of the body, including mental activity

• Calm, relative anxiety, may induce sleep• Large doses cause loss of consciousness, coma

and death

Ethanol (alcohol)

• Impairs judgement and slows down reflexes• Most countries have legal limits for the

amount of alcohol in the blood for motorists, airline pilots and people who operates machinery

• Can be determined by breathalysers, gas liquid chromatography (GLC), intoximeters

Abuse of alcohol; short term effects⁺ Relaxing and anti depressing† Difficulties to speak, walk, violent behaviour,

etc… Social effects? Cost to society?

Use and abuse of alcohol; long term effects

⁺ cardiovascular benefits from drinking 1 - 2 drinks per day

† an increased risk of developing alcoholism, cardiovascular disease, malabsorption, chronic pancreatitis, alcoholic liver disease, and cancer

Social effects? Cost to society?

Ethanol analysis with breathalysers

Oxidation of ethanol to ethanal by dichromate ions:Cr2O7

2- + 3C2H5OH + 8H+ → 2Cr3+ + 3CH3CHO + 7H2O

Orange Green

Oxidation of ethanol to ethanoic acid:2Cr2O7

2- + 3C2H5OH + 16H+ → 4Cr3+ + 3CH3COOH + 11H2O

Orange Green

Ethanol analysis with gas liquid chromatography (GLC)

Separation according to boiling point and polarity

Ethanol analysis with infrared intoximeters

Part A The Infrared Radiation is generated, usually from a quartz lamp.Part B The person breathes into this partPart C Where the breath comes outPart D The sample chamber, where the breath is stored.Parts E The lenses that focus the IR beam from the lamp.Part F The filter wheel, it filters out everything but specific wavelengths of the bonds in ethanol.Part G A photocell, which converts those wavelengths into an electric pulse.Part H The microprocessor, which interprets the electric pulse and calculates the Blood Alcohol Concentration based on the change in bond lengths in the ethanol.

http://optiond.wikispaces.com/D.4.3

Infrared spectroscopy of ethanol Certain infrared wavelengths can be absorbed by ethanol:

Ethanol analysis with fuel cell intoximeters

By oxidizing ethanol, you get acetic acid, and two hydrogen atoms (two protons, and two electrons) The devices using the fuel cell technology to detect alcohol have two platinum electrodes, and a electrolyte material in between.The protons then move across the electrolyte, while the electrons move through wires connected to the platinum plates. On the other side, the protons and electrons bond with oxygen to form water. The current across the wire is measured, and sent to a microprocessor, which calculates the alcohol content.

http://static.howstuffworks.com/flash/breathalyzer-fuel-cell.swf

Synergistic effects of ethanol and other drugs

• Since ethanol surpresses the central nervous system it has synergies with benzodiazepines, narcotics, barbiturates (sedatives) and solvents

• With aspirin ethanol increases the risk of stomach bleeding

• Increases the risk of heavy sedation with any drug affecting the central nervous system

Other Depressants

• Certain medicines known as antidepressants are used to treat anxiety, stress, clinical depression and insomnia– Benzodiazepine: diazepam (Valium)– Nitrazepam (Mogadon)– Fluoxetine hydrochloride (Prozac)

• Diazepam (Valium) – supresses the central nervous system

• Fluoxetine (Prozac)- makes the mood-affecting serotonine more available

• Nitrazepam (Mogadon)- treatment of moderate to severe

insomnia, sedative and motor impairing properties