IBDP SL Medicines and Drugs

1. Percentage yield for Aspirin
Synthesis

2. Describe the different methods of
getting a drug into the human body
and reasons why each method is
chosen
(include 3 types of parenteral
administration)

3. Syllabus References
• D1.4 Side effects, therapeutic window,
tolerance.

4. Side Effects
• Depends on the medicines intended use, e.g.
morhpine…..

5. Tolerance
• With constant use over time need more of the
drug to produce the same physiological effect.

6. LD50 / ED50
• Measure of safety
• If ED is small and LD is large then a wide
therapeutic window exists.

7. Dependence
• Physical
– Users body can only function normally with the
drug
• Psychological
– Intensifies craving for a drug.
• The above are both forms of drug addiction.

8. Syllabus Reference
• D2 Antacids – state and explain how acidity in
the stomach cab be reduced by the use of
different bases.

9. Placebo
• Where an inert substance produces a
significant reaction purely on the belief of the
individual.

10. Common Antacid Remedies
• Magnesium Oxide
• Magnesium Hydroxide
• Aluminium Hydroxide
• Calcium Carbonate
• Sodium Hydrogen Carbonate
• Magnesium Trisilicate
• 1. Stomach acid is HCl – write balanced chemical
equations for the rxn of HCl with the above.
• 2. Which is a better buy ? Sodium Bicarbonate or
Calcium Carbonate – explain using 1g of each.

11. Antacid – other ingredients
• Dimethicone – anti-foaming agents
• Alginates – protective neutralising ‘raft’
• http://www.gaviscon.co.uk/how_does_gavisc
on_work/double_action.php

12. Analgesics
• Mild
• Strong

13. Mild Analgesics
• Mild analgesics function by intercepting the
pain stimulus at the source, often by
interfering with the production of substances
(for example,prostaglandins) that cause pain,
swelling or fever.

14. Strong Analgesics
• Strong analgesics work by temporarily
bonding to receptor sites in the brain,
preventing the transmission of pain impulses
without depressing the central nervous
system.

15. Show me a picture ….

16. (MILD) Aspirin vsParacetamol
• Create one side of A4 which must include :-
– Full structural formulae
– Identification of and designation of all functional
groups
– Elucidate all bond angles with a single example of
each different value.
– Advantages and disadvantages of both, including but
not limited to; Reye’s syndrome, ulceration, stomach
bleeding, allergic reactions, blood disorders,
overdosage, kidney problems.
– Mechanism of action

17. Morphine cfDiamorphine (Heroin)

18. Social Costs…….
• http://www.youtube.com/watch?v=-
5GIonSHa8c
• http://www.youtube.com/watch?feature=end
screen&NR=1&v=TWfRBbRrj2w

19. Structures / Solubility / Bonding

20. Advantages and Disadvantages of
Using Opiates
• Short Term - sedation, stupor, relief from pain,
euphoria, impaired functioning, reduced tension,
worry and fear – occasional OD.
• Long term – malnutrition, constipation, risk of
AIDS due to shared needles, withdrawal, loss of
job, crime, sterility.
• Tolerance and dependence are both major factors
in opiate addiction.

21. Depressants
• At low doses a depressant may exert little or
no effect. At moderate doses the compound
may induce sedation (soothing, reduction of
anxiety).
• At higher doses it may induce sleep. At
extremely high doses it may cause death.
Depressants are often described as
antidepressants because they relieve
depression.

22. Types of Depressants
• Tranquilisers – slow down body and brain, include
ethanol and valium. Produce sleep, relieve
anxiety and tension.
• Sedatives – may be considered as strong
tranquilisers – sooth distress.
• Hypnotics – produce sleep, e.g. chloral hydrate.

24. Oxidation of alcohols
• Set up oxidation of alcohols practical

25. Ethanol – complete for homework
• Name two routes by which this drug can be
synthesised.
• List some of the short and long term effects of alcohol
use / abuse.
• Illustrate how this can be chemically changed from the
primary alcohol to aldehyde and carboxylic acid,
include conditions, and reagents.
• How does the breathalyser work ?
• How does blood and urine analysis determine alcohol
content in a person ?
• Explain synergistic effect with Aspirin.

26. http://www.youtube.com/watch?v=3-9wyHtN9n4

27. Starter
• Write the reduction and oxidation half ion
equations for ethanol / dichromate.
• HL: What is hybridisation in ethanol ?
• How many lone pairs ?
• What are the bond angles ?
• Name a nucleophile that would replace the
alcohol group, include curly arrow
mechanism.

28. Stimulants D5
• What is a stimulant ?
• Amphetamines, nicotine and caffeine are al
examples.
• They stimulate the CNS increasing wakefulness,
often accompanied by a decrease in appetite.
• Constrict arteries, increase sweat production,
increase heart rate, blood pressure, respiration,
then fatigue, irritability, depression.

29. Adrenalin

30. Amphetamine

31. PEAs

32. XTC

33. What do PEAs DO ?
• They are sympathomimetic – their actions
mimic the bodies natural stimulant –
adrenalin.
• Medical uses; treats mild depression,
narcolepsy, and asthma,
• http://www.youtube.com/watch?v=qyXFN4oc
N_o

34. D5.3 Nicotine
• Mild stimulant, followed by depression which
encourages frequent use.
• ST Effects; increases heart rate, and blood pressure, so
stresses the heart, diuretic.
• LT Effects; heart disease, thrombosis, excess stomach
acid, ulcers, cancers of the larynx, emphysema, and
fires !!
• HIGHLY ADDICTIVE !!! Psychological and physiological.
• http://www.youtube.com/watch?v=x4c_wI6kQyE

35. Caffeine, Nicotine

36. Effects of Caffeine
• Caffeine; increases cellular metabolism,
stimulates CNS, increases alertness, energy,
motivation and concentration. Diuretic. No
physical addiction, mild psychological.
• Weak diuretic.

37. D6 Antibacterials
• Research the role of Florey, Chain and Fleming
in the serendipitous discovery of penicillin.
• Produce a one piece info sheet on the
discovery, production and impact on the
world.

38. Antibac Essentials

39. Viruses vs Bacteria
• TB, typhoid, syphillis, gonnorhea, fever
• Note: Viruses are different and include;
influenza, the common cold, hepatitis,
measles and AIDS.

40. Action of Antibacterials
• Fleming – found an open petri dish with
mould in it – no bacterium  YEY
• Subsequently Florey and Chain scaled this up
to an industrial process.
• Saved thousands of lives in the closing years of
WW2.

41. Penicillin Structure

42. Notes
• Penicillin is deactivated by stomach acid so is
injected.
• The side chain has been modified to
counteract this.
• Some bacteria have evolved to deactivate the
bacterium.

43. Penicillin Mode of Action
• Penicillin is incorporated into the cell wall of
the bacterium.
• Ring strain causes the molecule to break and
create holes in the cell wall.
• Water enters by osmosis, the cell wall
expands, bursts, and the bacterium dies.
• http://www.youtube.com/watch?v=vK3nxfKM
4Q4

44. Broad and Narrow Spectrum Antibacs
• Broad – a wide variety of bacteria – the
tetracyclines – from soil fungi
– Prolblematic as kill all bacteria
• Narrow – only a small number ( sometimes
only one ) – this is the majority of penicillins

45. Over Prescription
• Safe for MOST people ( 10% allergic ) – shock
and death
• Can kill good bacteria – allowing bad bacteria
to proliferate
• Genetic resistance – typhoid, TB, gonnorhea
have all evolved resistance
• Mutated strains – no treatment
• Animal feedstocks – encourages drug
resistance

46. D7 Antivirals
• Submicroscopic, non cellular, parasitic, no
nucleus, much smaller than bacteria.
• Note : an antibiotic may have antiviral properties
• Most viruses are controlled by inoculations –
polio, smallpox, yellow fever, influenza.
• UN Smallpox vaccination programme has
eradicated this virus.

47. How do Antivirals Work ?
• http://www.youtube.com/watch?v=HhhRQ4t9
5OI
• Research focusses on blocking the viral
enzyme activity within the host cell.
• Acyclovir and Zovirax are common antivirals.

48. AIDS
• Viruses can cross species, mutating as they go.
• HIV contains RNA not DNA.
• Specific proteins on the surface of HIV bind to
CD4 receptors on white blood cells. These are
the bodies immune system.
• HIV mutates, and control is difficult due to the
high price of anti retro viral drugs.