IB ChemistryUnit 12: Option D Medicines and DrugsPart 2 (D4-D7 and D10)

D4 DepressantsDepressants (downers) are tranquilizers, sedatives and hypnotics. They calm and relax (depress) the CNS, brain activity and that of other organs is slowed. This leads to lower breathing and duller emotional responses.Low doses may have little effect, moderate doses can reduce anxiety and be soothing, higher does can induce sleep, very high doses may cause death.Depressants are often described as anti-depressants because they relieve depression.

TranquilizersTranquilizers include alcohol, valium (diazepam) and librium.They reduce nervous tension and anxiety but dont produce sleep in normal doses.Librium and valium (diazepam) are two common benzodiazepine tranquilizers used widely for relieving tension and anxiety. They are safer than barbiturates.

SedativeSome barbiturates are sedatives.They sooth distress without producing sleep in normal doses. They are have a stronger action than tranquilizers.

HypnoticsEx. Chloral hydrate. These are used to induce sleep.Phenobarbital (a barbiturate) can behave as a sedative or a hypnotic depending on the dose.

Depending on the dose any depressant can act as a tranquilizer, sedative, hypnotic, anesthetic or even be fatal.

AlcoholDraw the structure of and name the alcohol that people drink.Do you know what effects alcohol has on the body?What other uses are there for alcohol?

Alcohol Ethanol is water soluble due to the H on the OH group being able to form hydrogen bonds.It is also fat soluble due to the C-H group so it can pass through cells and tissues easily and is completely absorbed by the entire gastrointestinal tract.

Effects of Alcohol30-50 mg per 100 cm3 of blood leads to mild intoxication and a sense of euphoria.In people without tolerance, silly behavior is observed.At 100mg per 100 cm3 of blood, most people have neurological problems like slurred speech and staggering.Behavior can become aggressive and dangerous.

Effects of AlcoholAt 200mg per 100 cm3 of blood vision and movement are difficult and at 400mg per 100cm3 of blood, coma and death are likely.Alcoholism is an addiction to alcohol and is defined medically as a disease.It tends to be progressive and can be fatal.There is a genetic component to the disease which seems to be related to the levels of some enzymes in the body.

Uses of AlcoholAt least 80% of adults in Europe and N. America use (drink) alcohol at some point in their lives.Alcohol can be used as an antiseptic for medical use and is the solvent for iodine which is also used as an antiseptic.

The Cost of Alcoholism Society pays for most of the costs associated with alcoholism.These include hospital care, productivity lost due to ill health and death, crime, motor traffic costs, victims of traffic accidents and crime and their families.Offenders are often under the influence of alcohol when committing violent crimes.

Physiological Effects of AlcoholismInvolves a psychological addiction where the user is unable to control intake and feels compelled to drink. It is also a physical addiction.Usually interferes with work, home and school life, leads to problems in relationships, dangerous behavior, physically harming someone.Withdrawal includes nausea, sweating, anxiety, increased blood pressure when alcohol is stopped.Tolerance involves need for more alcohol to feel same effect.

Short-Term EffectsModerate amounts: CNS is depressed; euphoria, sociability, talkativeness, feeling relaxed, more confident, less inhibited, feeling of warmth due to small blood vessels in skin being dilated.Increased amounts: loss of judgement, impairment of perception, memory and comprehension, driving accidents more likely as reaction time increases.

Short-Term EffectsHigher amounts: violent or aggressive behavior, slurred speech, dizziness, double vision, loss of balance, nausea, vomiting.Eventually consciousness can occur as well as death from respiratory arrest.

Long-term effects Cancer and cirrhosis due to scar tissue of the liver, coronary heart disease, high blood pressure, stroke, gastritis, peptic ulcers.Physical dependence and tolerance. Anxiety, depression and poor eating habits are common.Excess drinking by pregnant women can lead to miscarriage, low birth mass and fetal abnormalities including poor development in infants. Fetal Alcohol Syndrome (FAS) refers to physical and mental birth defects from a woman drinking too much alcohol during pregnancy.

Synergistic EffectsThis effect is when a combination of two drugs is much more harmful than either drug taken alone the effect is more than doubled.Alcohol is synergistic with sedatives like sleeping pills and barbiturates. The CNS becomes so depressed that coma and death can result.Alcohol and aspirin increase the risk of stomach bleeding.

Synergistic EffectsAlcohol and cocaine produce cocaethylene which may extend the cocaine high but is much more toxic than either drug alone.Severe vasoconstriction occurs leading to increased blood pressure and arythmogenecity (irregular heart beat).Alcohol can be fatal when used with benzodiapenes like valium and mogadon, again the nervous system is suppressed.

D.4.3 Describe and explain the techniques used for detection of ethanol in the breath and in blood and urine.Blood Alcohol Concentration (BAC) is the mass of grams of ethanol per 100cm3 of blood. This is also listed as a percentage in some countries or as mg/ml.Most countries have the legal driving limit between 0 and 0.08% (80mg alcohol per 100cm3 blood or 0.8mg/ml).Do you know what is it in the USA? The UK? Mexico? Canada?

Breathalyzer TestEthanol passes from the stomach into the blood stream and passes into the lungs where an equilibrium is established at the bodys temperature: C2H5OH(blood) C2H5OH(vapor)The concentration in the lungs will depend on the BAC and will decrease over time as it is metabolized in the liver.The roadside breathalyzer test used by police involves a redox reaction.

Breathalyzer TestThe oxidizing agent is acidified potassium dichromate which oxidizes any ethanol in the breath.What forms? What color change would be seen? (we did this in organic chem!)

Breathalyzer TestThe half-equations are:Cr2O72- +14H+ + 6e- -> 2Cr3+ + 7H2O

C2H5OH + H2O -> CH3COOH + 4e- + 4H+

Use these to write the overall equation. Which half is oxidation and which is reduction?

Breathalyzer TestThe transfer of electrons in the redox reaction generates an e.m.f. that is converted to a signal in the device to indicate the BAC in the sample of breath.This is not a very accurate device and is unreliable in legal cases. More accurate analysis is carried out by gas liquid chromatography (glc) and infra-red spectroscopy.

Gas Liquid ChromatographyThis method can separate and identify very small samples of gases and volatile liquids from breath, blood or urine.GLC uses a stationary phase (non-volatile liquid or solid) and a mobile phase (inert carrier gas like N2).The sample is injected into this system and the components move through the column at different rates depending on their boiling points.

Gas Liquid ChromatographyThe time it takes for each component to move through the column is called the retention time.A detector records each substance as it leaves the column on a chromatogram. The area under the peak shows the amount of each substance present.GLC can be used to measure other drugs at the same time as ethanol.

Gas Liquid Chromatography

Infra-Red SpectroscopyInfra-red (IR) energy cannot excite electrons to higher energy levels but it can cause vibrations in a molecule. The vibrations are affected by mass of the atoms and the length/strength of the bonds in the molecule.IR spectra use the wavenumber scale. This is simply the reciprocal of the wavelength (1/) so the units are cm-1. The IR range is from 667 to 4000 cm-1.

Infra-Red SpectroscopyC-H bonds in ethanol are seen at 2950 cm-1 whereas O-H are seen at 3340 cm-1.The O-H peak cannot be used as it is also present in water so the C-H peak is used.Police can use the Intoximeter to confirm a breathlyser test at the roadside. It is an IR spectrophotometer where IR is passed through the breath sample.

IR SpectroscopyIf alcohol is present, the frequencies are absorbed by the sample depending on the bonds present and the rest of the radiation is transmitted.The intensity of the IR radiation is compared to that of air and usually recorded as a % transmittance.The Intoximeter cannot distinguish between ethanol and propanone which is in the breath of diabetics but GLC can.

Other DepressantsValium is a sedative. It is the most prescribed drug in the world and used to treat anxiety and tension. It inhibits nerve transmission by interacting with neurotransmitters.Nitrazepam (Mogadon) is a common sleeping pill. It is a hypnotic drug that induces sleep and also controls seizures and infant spasms.Both drugs are synthetic and are benzodiazepines.

Other DepressantsBoth have a common structure with a phenyl group (C6H5), a fused benzene ring with a seven-membered heterocyclic ring consisting of 2 N atoms, one of which is a secondary amine. On the fused benzene ring, valium contains Cl whereas Mogadon contains the NO2 group.Nitrazepam(Mogadon)

D5 StimulantsStimulants (also called uppers) have the opposite effect to downers. They cause increased mental alertness by stimulating the brain and CNS.In many cases they decrease appetite so are used as diet pill. Examples are amphetamines, nicotine and caffeine.

Adrenaline and AmphetaminesWhat is adrenaline? How does it work?Amphetamines have similar chemical structures to adrenaline. Both are derived from phenylethylamine.phenylethylamineadrenalineamphetamine

AmphetaminesAmphetamines mimic the effects of adrenaline and are called sympathomimetic drugs what does this mean?They resemble the actions of the stimulated sympathetic nerves.Amphetamines are strong stimulants and act on the CNS, mainly the brain.They are prescribed for mild depression, narcolepsy and asthma (they cause broncodilation).

AmphetaminesEffects: increased heart rate, blood pressure, respiration, wakefulness, restlessness, insomnia, temporary elevation of mood followed by fatigue, irritability and depression.The drugs allow the body to use reserve energy like adrenaline but this can be followed by sudden exhaustion, blackout or collapse.

EcstasyEcstasy is a designer drug. It is made by illegally modifying the amphetamine structure to avoid existing drug laws.It has a similar structure to methamphetamine and the hallucinogen mescaline. It is more potent than amphetamine and can be fatal after one dose.

NicotineNicotine is an nitrogen containing alkaloid found in tobacco. It has a short mild stimulant effect which is followed by depression leading to frequent use.Short-term effects: increased heart rate and blood pressure, blood vessels constricted puts stress on heart which can lead to heart problems. Urine production is also reduced.

NicotineLong-term effects: risk of heart disease and coronary thrombosis (clots) are increased as it may also cause an increase in fatty acids in the blood.CO is produced by smoking which bonds more favorably to hemoglobin than O2 this places more stress on the heart.It may produce excess acid in the stomach increasing the risk of peptic ulcers.Smoking also contains many other toxic chemicals.

SmokingSmoking causes:Cancer of lung, larynx and mouthHeart and blood vessel diseaseEmphysemaChronic bronchitisAir pollutionFiresYellow stained fingers and teeth, bad breath.

Nicotine AddictionNicotine is much more addictive than alcohol or barbiturates.It produces psychological dependence and tolerance develops.Heavy smokers can develop physical dependence too.Withdrawal symptoms: weight gain, nausea, insomnia, irritability, fatigue, difficulty concentrating, depression and craving cigarettes.

CaffeineAn alkaloid found in tea, coffee, soft drinks and chocolate.Affects CNS by increasing metabolism inside nerve cells.Stimulates CNS, heart, kidneys, lungs and arteries supplying blood to the heart and brain.In moderate doses caffeine enhances alertness, well-being, motivation and concentration. It can help long periods of studying.

CaffeineIn small amounts it is considered relatively harmless but large amounts, it can cause sleeplessness. It also stimulates the kidneys so is a weak diuretic.Some caffeine tolerance can develop but no physical addiction. There is some minor psychological addiction morning grouchiness.Medically caffeine is used to help babies with respiratory difficulties as it can stimulate breathing.Caffeine is a vasoconstrictor so it may help reduce migraines caused by dilation of blood vessels.

CaffeineCaffeine is heterocyclic with some Cs replaced by Ns in the ring. It has a tertiary amine group like nicotine fitting the general R3N formula.Caffeine

D6 AntibacterialsAntibacterials (antibiotics) are drugs that inhibit the growth of or kill microorganisms that cause infectious diseases.The drugs are selective to particular types of bacteria. Antibiotics aid white blood cells by preventing bacteria from multiplying either by inhibiting cell division (bacteriostatic drugs) or by killing the bacteria (bacteriocidal drugs).

Bacterial InfectionsAntibiotics will have no effect on viruses as they do not have the prokaryotic cell structure that bacteria do.What examples of bacterial infections do you know?What examples of viruses do you know?

PenicillinsWhat do you know about penicillin and how it was discovered?

PenicillinsFungal mould penicillium notatum inhibits bacterial growth.Alexander Fleming saw this effect in 1928 in London. He found it too difficult to isolate the penicillin compound.In 1940 Florey and Chain renewed research and experimented on mice.First human (London Police man) received penicillin in 1941.

PenicillinsMassive development of penicillins carried out in the US penicillin grown in corn-steep liquor in large fermentation tanks.Available clinically in 1943 and widely available in 1945.Fleming, Florey and Chain won Nobel Prize for medicine in 1945.How is the timing of this historically significant?

PenicillinsThe first penicillin was penicillin G. Its structure was found by X-ray crystallography and other penicillins were made. Penicillin G is deactivated by stomach acid so had to be injected. Penicillin V (phenoxymethylpenicillin) is acid resistant so can be taken orally.Some bacteria can also deactivate penicillins with the enzyme penicillinase so other penicillins were developed by modifying the side chain.

PenicillinsThe common structural feature is 6-APA (6-aminopenicillanic acid). It has little effect on bacterial growth on its own but becomes active when a side chain is added to its NH2 group.

Broad and Narrow SpectrumBroad spectrum antibiotics work against a wide range of bacteria whereas narrow spectrum are more selective.Most penicillins and sulfa drugs are narrow spectrum. Tetracyclines are broad spectrum ex. Aureomycin and terramycin mycin indicates antibiotics from soil fungi.Broad spectrum antibiotics can attack good bacteria as well as harmful bacteria particularly in the digestive tract. Why is this a problem?

Bactericidal ActionPenicillins kill bacteria by interfering with the formation of cross links in the cell wall. These are made of polysaccharides. Animal cells dont have a cell wall the patients cells are not affected.The bacteria can make all the components of its cell but cannot construct the cell wall to protect itself. This means water enters by osmosis, the cell expands, bursts and dies.

Effects of Over Prescription of PenicillinsRepeated use can lead to severe allergic reaction 10% of population suffer from this with the first dose.Harmless and helpful bacteria in the digestive system may be wiped out. Destroyed bacteria may also be replaced by more harmful bacteria.Genetic resistance can occur ex. Typhoid, gonorrhea and TB all have resistant strains.

MutationsAn organism may also become resistant through mutation. Continuing research to find new antibiotics is therefore necessary.The number one rule for antibiotics is only to use them when no other treatment will reduce suffering or save life.Patient cooperation is necessary to make sure these drugs are effective. With TB a combination of drugs are needed.

LivestockAntibiotics are added to animal feedstock. These are to boost growth of the animals and to protect them against pathogens in the feed.Low level exposure to antibiotics leads to resistant strains of E. coli and salmonella among others, which are then consumed by humans. The antibiotics used are the same as those used to treat humans so there are concerns about this practice.

D7 AntiviralsViruses are submicroscopic infectious particles. They are not composed of cells and can only reproduce by invading a host cell and using the hosts enzymatic machinery.Viruses have their own DNA or RNA which is surrounded by a protein coat called a capsid. Some also have a membrane around the capsid.

Antiviral drugsMost antibiotics are completely ineffective against viruses. If an antibiotic is able to block gene transfer then it may be effective against some viruses too.The most effective way to deal with viruses is with inoculations. These have been very successful at wiping out or coming close to wiping out poliovirus, smallpox and yellow fever. Influenza is also controlled by inoculations.

Treating VirusesMany new and emerging diseases are viral and treating them is a huge area of research and development.A virus reproduces by attaching to a host cell and releasing its genetic material into the cell. They stimulate the hosts cell to make many copies of the viral DNA / RNA. The nucleic acid particles are coated with protein and released to infect other cells.These steps require many enzymes so one goal of research is to block some of these steps.

Treating VirusesAnother approach is to alter the cells ribosomes so that the virus cannot use them to multiply.One successful antiviral drug is Acyclovir (Zovirax) used to treat genital herpes orally and topically. The drug relieves the pain and itchiness and shortens outbreaks. However it cannot prevent recurrences and does not work for every patient.

Treating VirusesSome cancers are caused by viruses. These dont tend to act immediately but insert their nucleic acid into the host cells so that they are passed onto daughter cells.Over time and when stimulated the virus will leave its latent state in cells and cause damage.Herpes simplex is an example of a latent virus which hides in nerve cells. When reproduces cell damage occurs called a cold sore.

AIDSViruses can cross the species barrier to infect outside of their normal hosts. They also mutate frequently making them hard to develop vaccines for.Human Immunodeficiency Virus (HIV) is a retrovirus containing RNA which mutates frequently. HIV infection leads to AIDS (Acquired Immuno Deficiency Syndrome) which was first reported in the US in 1981.

HIVHIV progressively destroys the bodys ability to fight infections. It does this by attacking specific cells especially white blood cells of the immune system.This leads to life threatening infections like pneumonia that normally are not a threat to healthy people. A person is considered to have AIDS in the most advanced stages of HIV infection.

HIV mechanism of actionThe HIV virus binds to the CD4 receptor glycoprotein that is present on T-4 lymphocytes.What are lymphocytes? What to they do?The HIV virus has a similar metabolism to the human cell and mutates very often. This makes it difficult to treat by drugs or vaccines.

HIVThis is made worse by the high price of antiretrovirals and socieo-economic issues found in many developing countries that are afflicted by the HIV epidemic. What countries or regions do you know that are affected by HIV?

D10 Mind Altering DrugsAlso called psychedelic drugs or psychotomimetics (simulating madness) or hallucinogens.What is a hallucination?Psychedelic means something causing an abnormal stimulation or feeling of consciousness.

D10 Mind Altering DrugsThese mind-bending or mind-altering drugs produce a qualitative change in thought, perception or mood and can cause vivid illusions and fantasies.Touch, smell, hearing and vision can all be distorted and cause illusions.What are some examples of these sensations?

ExamplesLSD (lysergic acid diethylamide)Mescaline (one of the oldest known hallucinogens)Psilocybin (from magic or liberty cap mushrooms)THC (tetrahydrocannabinol) from marijuana (also called grass, pot).

LSD: Lysergic acid diethylamidePowerful hallucinogen made from lysergic acid, found in ergot a fungus that grows on rye and other grains.Experience is very personal, effect varies with dose, physiological condition, psychological condition and the users expectations.Perception is magnified, sense of judgment is gone (ex. Jumping off building).

LSD: Lysergic acid diethylamideCan cause strong opposite emotions at the same time ex. Relaxation and tension.Physical effects of a trip (lasts about 8 hours): dilation of pupils, increase in heart rate, blood pressure and body temperature, sweating, sleeplessness, tremors.Frightening bad trips as well as flash backs afterwards can occur.

LSDPhysical addiction is not really seen but tolerance can develop then disappear rapidly.Psychological dependence can occur but not as strongly as with other drugs.LSD appears to interact with serotonin receptors on neurons by preventing neurotransmitters from making connections between neurons in the brain.

MescalineComes from peyote cactus in Central and S. America has been used for centuries.Produces visual color hallucinations, much less potent than LSD.Trip lasts about 12 hours and leads to decrease in appetite.Produces much worse effects with alcohol and can lead to liver damage over time.

PsilocybinThe major hallucinogen in magic mushrooms.A mild hallucinogen, magnifies perception, less potent than LSD.In low doses it produces relaxation similar to cannabis. High doses are similar to LSD effects.Colors are intensified, hallucinations occur and there is a sense of well-being.Trip lasts about 4 hours.

PsilocybinNot addictive in nature but there is some tolerance.Psilocybin and mescaline, like LSD, resemble serotonin and bind with the same receptors in the brain to over stimulate them.

Tetrahydrocannabinol (THC)Cannabis (marijuana) comes from the Cannabis sativa plant.Hashish is made from the resin of the flowering tops of the plant and is a psychoactive product.The main psychoactive ingredient is tetrahydrocannabinol (THC).THC is a mild hallucinogen and has some similar effects to alcohol.

Tetrahydrocannabinol (THC)Low doses make users feel excited and silly.Higher doses lead to changes in perception (brighter colors, better hearing), visual hallucinations (objects in odd shapes).Initial joy can turn to anxiety, depression, uneasiness, panic attack and fearfulness.Decision making is difficult and a user is likely to follow others.

Tetrahydrocannabinol (THC)Tasks that require good reflexes and clear thinking become difficult.Tolerance does not develop but regular use can lead to moderate psychological dependence.Cannabis smoke contains similar toxins to cigarette smoke so similar risks like cancer are increased.

StructuresAn INDOLE is a heterocyclic amine compound that has the N atom as part of the ring. It also has a benzene ring fused to it where they share a C=C bond.

LSDmescalinepsylocybinserotonin

StructuresLSD has an indole along with a diethyl amine side chain. It is fat soluble and easily diffuses into the brain. It can also cross the placental barrier into a fetus.Mescaline has the benzene ring but doesnt have the fused ring attached. Instead it has a primary amine group.Psilocybin has the indole ring and a dimethylamine side chain along with a dihydrogen phosphate group.

StructuresThe backbone structure of psilocybin is the same as serotonin but has different side chains which give rise to the different properties among the hallucinogens.The side groups also affects their solubility in fats more fat soluble molecules will penetrate the cell membranes of nerve cells and the greater their potency. Methyl groups increase this and polar groups like phosphoric acid reduce it.

Should Cannabis be Legal?Arguments for:Cannabinoids offer relief from AIDS, cancer and glaucoma.In AIDS patients a wasting syndrome is seen, cannabis is thought to help by increasing appetite again.Cannabis is thought to relieve nausea in chemotherapy patients so that they can keep food down and gain weight.

Should Cannabis be Legal?In some countries it is given to relieve tension and anxiety in some terminally ill cancer patients.It thought to relieve pressure inside the eyeball to help prevent damage to the eyes of glaucoma patients.Legalization would allow better quality control and fewer harmful impurities causing problems.It would also disassociate cannabis from environments where hard drugs are available.

Should Cannabis be Legal?Arguments against:Smoking marijuana regularly can lead to respiratory problems associated with inhaling smoke.Regular use may suppress the bodys immune system and increase susceptibility to disease.Decreased fertility has been seen in some men.Brain damage has been seen in rats (although less than with alcohol).

Should Cannabis be Legal?Chromosomal damage may lead to birth defects.Cannabis users might move onto harder drugs not clear if this would happen if cannabis was legal.

Illegal Drugs Using illegal drugs means obtaining them from criminal sources, paying more than they are worth and often being force into crime and/or prostitution to pay for the habit.This is bad for society in general so some governments choose to control the supply of hard drugs to drug addicts this doesnt mean they are legal.

Illegal DrugsAn example of controlling substances was prohibition of alcohol in the USA in 1919 to 1933 it was so widely disobeyed and lead to organized crime that is was scrapped.Trying to contain the abuse of legal and illegal drugs and the negative impact it has on society is a challenge that faces us all.

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