Medicines and drugs Depressants

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 depressants doseeffect lowmay exert little or no effect. moderatemay induce sedation, soothing, reduction of anxiety, impaired judgment highmay induce sleep, unconsciousness, slurred speech, altered perception extremely highmay 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 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: C 2 H 5 OH + H 2 O → CH 3 CHO + CH 3 COOH (ethanal + carbox acid) reduction: Cr 2 O 7 2 − + 14H + +6e − → 2Cr H 2 O

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 CO 2 and H 2 O The energy released in this reaction is converted into a detectable electrical voltage to measure ethanol concentration.

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/Mogado n®;  amide/ketone/carbonyl;  (tertiary) amine; Anti- depressant Sleeping pills And muscle relaxants

Other commonly used depressants Differences C- has no H’s ( is sp 2 - 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