DepressantsDepressants

L. SchefflerL. Scheffler

DepressantsDepressants

Depress the central nervous Depress the central nervous system by interfering with the system by interfering with the transmission of neural transmission of neural impulses in the nerve cells impulses in the nerve cells (neurons)(neurons)

Effects of DepressantsEffects of Depressants

Slow down bodily functions Slow down bodily functions especially motor activity and especially motor activity and mental activitymental activity

Low dosesLow doses– Feelings of calm and reduced anxietyFeelings of calm and reduced anxiety– Induced sleepInduced sleep

Large dosesLarge doses– Loss of consciousness, coma, deathLoss of consciousness, coma, death

AlcoholAlcohol

Ethanol is the only common Ethanol is the only common alcohol that can be consumed. alcohol that can be consumed. Other common alcohols such Other common alcohols such as methanol and isopropyl are as methanol and isopropyl are much too toxic.much too toxic.

Alcohols are used as Alcohols are used as antiseptics for injections and antiseptics for injections and to harden skinto harden skin

AlcoholismAlcoholism

Prolonged consumption of Prolonged consumption of alcohol leads to both alcohol leads to both psychological and physiological psychological and physiological dependencedependence

Alcoholism also results inAlcoholism also results in– Violent antisocial behaviorViolent antisocial behavior– Social costs to familiesSocial costs to families– Safety issues especially road Safety issues especially road

accidentsaccidents

Alcohol ConsumptionAlcohol Consumption

Short term effectsShort term effects– Relaxation, confidence, and Relaxation, confidence, and

increased sociabilityincreased sociability– Dialation of blood vessels leads Dialation of blood vessels leads

to feelings of warmthto feelings of warmth– Impaired judgmentImpaired judgment– Lengthened neural response Lengthened neural response

timetime

Alcohol ConsumptionAlcohol Consumption

Long term effects of heavy Long term effects of heavy drinkingdrinking

Cirrhosis of the liver and liver Cirrhosis of the liver and liver diseasedisease

Coronary heart diseaseCoronary heart disease High blood pressure and strokesHigh blood pressure and strokes DementiaDementia MiscarriageMiscarriage Fetal abnormalities and fetal Fetal abnormalities and fetal

alcohol syndromealcohol syndrome

Synergistic Effects of Synergistic Effects of AlcoholAlcohol

Ethanol can interact with other drugs, Ethanol can interact with other drugs, often enhancing their effect, because it often enhancing their effect, because it inhibits the functioning of the central inhibits the functioning of the central nervous systemnervous system

The The synergistic effectsynergistic effect can be fatal when can be fatal when alcohol is taken with certain drugs alcohol is taken with certain drugs includingincluding– BenzodiazepinesBenzodiazepines– NarcoticsNarcotics– BarbituatesBarbituates

When taken with aspirin it increases the When taken with aspirin it increases the likelihood of stomach bleedinglikelihood of stomach bleeding

Alcohol WithdrawalAlcohol Withdrawal

Sudden discontinuation of alcohol Sudden discontinuation of alcohol by heavy drinkers leads to by heavy drinkers leads to withdrawal symptoms includingwithdrawal symptoms including– DeliriumDelirium– Tremors’Tremors’

Legal limits for drivingLegal limits for driving

All states in the US and many All states in the US and many countries have established countries have established 0.08% blood alcohol as the legal 0.08% blood alcohol as the legal limit for driving.limit for driving.

After drinking the concentration After drinking the concentration of alcohol in the blood increases of alcohol in the blood increases as the alcohol is absorbed and as the alcohol is absorbed and then gradually declines.then gradually declines.

Legal limits for drivingLegal limits for driving Estimates of the alcohol consumption Estimates of the alcohol consumption

needed to exceed the legal limit of 80 mg needed to exceed the legal limit of 80 mg per 100 cmper 100 cm33 of blood for an average adult. of blood for an average adult.

1 unit = 280 cm3 of beer= Glass of wine= Shot of liquor

Time taken Time taken for drinking in for drinking in

hourshours

Number of Number of units menunits men

Number of Number of units womenunits women

11 4.04.0 2.82.8

22 5.05.0 3.53.5

33 6.06.0 4.24.2

44 6.56.5 4.54.5

55 7.57.5 5.25.2

Values are based on an average adult male weighing 150 pounds. Unit valuesFor women are somewhat less due to a lower body mass and lipid distribution

Alcohol detectionAlcohol detection

Breathalyser testsBreathalyser tests Reduction of potassium Reduction of potassium

dichromate to Crdichromate to Cr3+3+ ion ion Fuel cell where alcohol is Fuel cell where alcohol is

oxidized to produce an electric oxidized to produce an electric currentcurrent

Infrared spectroscopy- Infrared spectroscopy- intoximeterintoximeter

Gas ChromatographyGas Chromatography

Chemical Chemical BreathalyzersBreathalyzers

The dichromate ion, CrThe dichromate ion, Cr22OO772-2-, has an orange color , has an orange color

while chromium (III) ion, Crwhile chromium (III) ion, Cr3+3+, is green. , is green. By determining the level of green color present one By determining the level of green color present one

can determine the ethanol concentration.. can determine the ethanol concentration.. The ethanol absorbed by the dichromate solution can The ethanol absorbed by the dichromate solution can

be calibrated against blood alcohol levelsbe calibrated against blood alcohol levels The reaction is somewhat time dependent, therefore The reaction is somewhat time dependent, therefore

it is necessary to compare colors rather than titrate it is necessary to compare colors rather than titrate the solution to an endpoint.the solution to an endpoint.

Chemical Chemical BreathalyzersBreathalyzers

Alcohol chemical breathalyzer tests employ a Alcohol chemical breathalyzer tests employ a chemical colorimetric test to ascertain alcohol chemical colorimetric test to ascertain alcohol blood levels. blood levels.

This test is based on the fact that primary This test is based on the fact that primary alcohols such as ethanol are oxidized by acidified alcohols such as ethanol are oxidized by acidified potassium dichromate as followspotassium dichromate as follows

  3 C3 C22HH55OH + 2 CrOH + 2 Cr22OO77

2-2- + 16 H + 16 H++ 3 CH 3 CH33COOH + 4 CrCOOH + 4 Cr3+3+ + 11 H + 11 H22OO

  

Other DepressantsOther Depressants

Certain medicines known as Certain medicines known as antidepressants are used to antidepressants are used to treat anxiety, stress, and treat anxiety, stress, and clinical depressionclinical depression

These includeThese include– Diazepam (Valium)Diazepam (Valium)– Nitrazepam Nitrazepam – Fluoxetine hydrochloride Fluoxetine hydrochloride

(Prozac)(Prozac)

Fluoxetine Fluoxetine Hydrochloride (Prozac)Hydrochloride (Prozac)

Prozac is an example of Prozac is an example of the selective serotonin the selective serotonin reuptake inhibitor (SSRI)reuptake inhibitor (SSRI)

SSRIs work by preventing SSRIs work by preventing neurons (nerve cells) from neurons (nerve cells) from pulling in the serotonin that pulling in the serotonin that is floating in the space is floating in the space between neurons. This between neurons. This allows more serotonin to allows more serotonin to build up and improves build up and improves communication between communication between the neurons. the neurons.

TranquilizersTranquilizers ValiumValium XanexXanex NitrazepamNitrazepam

• Tranquilzers depress the nervous system responses but do not address the underlying problems.

• They are used to sedate people in the short term but can be very addictive

TranquilizersTranquilizers Tranquilizers are often Tranquilizers are often

temporarily prescribed temporarily prescribed for people facing high for people facing high stress or anxiety.stress or anxiety.

ValiumValium XanaxXanax • These drugs are usually

prescribed for brief time until counseling and psychotherapy can be put in place.

• They are occasionally used as a pre-medication before surgery.

• Prolonged and over use of tranquilizers results in drug dependence.

Xanex – A Common Xanex – A Common TranquilizerTranquilizer

Xanex is a Xanex is a common common tranquilizer tranquilizer prescribed for prescribed for persons suffering persons suffering from acute from acute anxiety. anxiety. Prolonged use can Prolonged use can lead to addictionlead to addiction

The Chemical structure ofXanex

HalcionHalcion

Halcion is a trade Halcion is a trade name for a type of name for a type of compounds known compounds known as a as a benzodiazopine. It benzodiazopine. It is similar in is similar in structure to other structure to other tranquilizerstranquilizers

Halicon is a commonly prescribed sleeping medicine

• Barbiturates are short acting, and include pentobarbital, secobarbital, and amobarbital.

• Affect the cortex and create a state similar to alcoholic intoxication in large doses.

• Extremely dangerous when mixed with alcohol or other drugs.

• A person in withdrawal suffers anxiety, agitation, loss of appetite, nausea and vomiting, sweating, a fast heartbeat, tremors, and cramps.

• These symptoms can escalate to convulsions, delirium, and hallucinations.

BarbituatesBarbituates

Some BarbituatesSome Barbituates

Barbiturates have Barbiturates have been known since been known since 1864 when Dr. A. 1864 when Dr. A. von Bayer von Bayer synthesized synthesized barbituric acid.barbituric acid.

In 1903, barbital In 1903, barbital was introduced as was introduced as a hypnotic for a hypnotic for routine medicinal routine medicinal use. use.

Barbituic Acid

Sodium pentathol