Medicines and drugsDepressants

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.

Terminology

Depression – clinical condition characterized by mood changes and loss of interest in normal activities.

The drugs used to treat depression are called antidepressants.

Effects of depressantsdose effect

low may exert little or no effect.

moderate may induce sedation, soothing, reduction of anxiety, impaired judgment

high may induce sleep, unconsciousness, slurred speech, altered perception

extremely high may cause organ failure or death

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

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

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

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.

How to detect ethanol1. 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.

Equationsoxidation: C2H5OH + H2O → CH3CHO + CH3COOH

(ethanal + carbox acid)reduction: Cr2O7 2− + 14H+ +6e− → 2Cr3+ + 7H2O

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

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).

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.

Other commonly used depressants

depressant structure: functional groups

Fluoxetine hydrochloride (Prozac®)

• aromatic benzene, ether, secondary amine, fluorine, chloride ion

diazepam/Valium®; amide/ketone/carbonyl; (tertiary) amine;

nitrazepam/Mogadon®;

amide/ketone/carbonyl; (tertiary) amine;

Anti-depressant

Sleeping pillsAnd muscle relaxants

Other commonly used depressants

Differences

C- has no H’s ( is sp2 - HL)

Tertiary amine

Amide

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