Drugs and Medicine HL

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Drugs and Medicine HL
2014-01-09 01:57:08

IB options test (Konwalia)
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  1. List the effects of medicines and drugs on the functioning of the body.
    • Generally, a medicine or drug is any chemical that does one or more of the following.
    • • Alters the physiological state, including consciousness, activity level or coordination
    • • Alters incoming sensory sensations
    • • Alters mood or emotions
    • The importance of the body’s natural healing processes and the placebo effect: when patients gain therapeutic effect from their belief that they have been given a useful drug, even when they have not and thus the body is able to heal naturally.
  2. Outline the stages involved in the research, development and testing of new pharmaceutical products.
    • Discovery research: involves identifying and extracting compounds that have been shown to have biological activity and are known as lead compounds
    • Development Research: the effectiveness of the drug is judged by the relative improvement in the patients who have received the real medication compared with those on a placebo.
    • Regulatory review: regulate whether it is sufficient or not
    • Post-marketing monitoring: safety surveillance programmes for all approved drugs, and databases are available that give details of adverse drug reactions

    An example of what can go wrong is the Thalidomide case. 
  3. Describe the different methods of administering drugs.
    • Methods should include oral, parenteral (by injection), inhalation, skin patches, suppositories, ear or eye drops.
    • Injections may be intravenous, intramuscular or subcutaneous.
  4. Oral Method
    • taken by mouth 
    • ex. tablets, capsules, pills, liquids
  5. inhalation method
    • vapour breathed in; smoking
    • ex: medications for respiratory conditions such as asthma; some drugs of abuse such as nicotine and cocaine
  6. skin patches method
    • absorbed directly from the skin into the blood
    • ex; some hormone treatments e.g estrogen, nicotine patches
  7. suppositories method
    • inserted into the rectum
    • ex: treatment of digestive illnesses, hemorrhoids
  8. eye or ear drops method
    • liquids delivered directly to the opening
    • ex. treatments of infections of the eye or ear
  9. parenteral-by injection
    • intramuscular - many vacciens
    • intravenous: fastest method of injection - local anaesthetics
    • subcutaneous- dental injections
  10. therapeutic window
    the range of a drug's concentration in the blood between its therapeutic level and its toxic level
  11. tolerance
    • the reduced response to a drug, a higher dosage is needed in order to create the same effect. 
    • Occurs when repeated doses of a drug result in smaller physiological effects
  12. side-effects
    defined as physiological effects which are not intended and vary greatly from one drug to another and different people.
  13. State and explain how excess acidity in the stomach can be reduced by the use of different bases.
    • antacids  combine with alginates to  produce a neutralizing layer, preventing acid in the stomach from rising into the esophagus and causing heartburn
    • antacids combine  with antifoaming agents (such as dimethicone).
    • ex. aluminium and magnesium compounds and sodium hydrogencarbonate.
  14. Describe and explain the different ways that analgesics prevent pain.
    • 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
    • .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. Describe the use of derivatives of salicylic acid as mild analgesics, and compare the advantages and disadvantages of using aspirin and paracetamol (acetaminophen).
    • Aspirin has been found to be useful in preventing the recurrence of heart attacks and strokes. The disadvantages of aspirin include ulceration and stomach bleeding, allergic reactions and Reye’s syndrome in children (a potentially fatal liver and brain disorder).
    • Paracetamol is very safe in the correct dose but can, in rare cases, cause blood disorders and kidney damage. Overdosage can lead to serious liver damage, brain damage and even death.
  16. Compare the structures of morphine, codeine and diamorphine (heroin, a semi-synthetic opiate).
    • common base structure
    • Codeine                 Morphine        Diamorpine (heroin)
    • benezene ring      benezene ring           benzene ring
    • ether (2)              ether                           ether
    • alkene                  alkene                          alkene
    • alcohol(1)            alchohol (2)              ester- ethanoate (2)
    • tertiary amine       tertiary amine             tertiary amine
  17. Discuss the advantages and disadvantages of using morphine and its derivatives as strong analgesics.
    • Morphine is a powerful analgesic, acting on the central nervous system to block the perception of pain.
    • Side effects:
    • causing constipation
    • suppressing the cough reflex
    • causing constriction of the pupil in the eye
    • narcotic effects
  18. Describe the effects of depressants.
    • Low to moderate dose: calmness, relief from anxiety, very relaxed muscles (tranquilizer)
    • High dose: slurred speech, staggering gait, altered perception, sleep induced (sedative)
    • Extremely high doses/lethal dose: respiratory depression, coma/death (hypnotic)
  19. Discuss the social and physiological effects of the use and abuse of ethanol.
    • Social use: used in alcoholic drinks as an important part for diet and culture, gives a sense of occasion to meals, ritual and festivities.
    • Physiological effects of abuse: 
    •     Short term: loss of self-restraint; memory, concentration and insight are impaired
    • loss of balance and judgement
    • violent behaviour associated with domestic abuse and family breakdown
    • dangerous risk-talking behaviour leading to many accidenty involving motor vehicles and machinery 
    • dehydration caused by increased urine output leading to 'hangover' and loss of productivity
    • at high doses, can cause vomiting, loss of consciousness, coma and death
    •    Long-term effects:
    • dependence known as alcoholism, associated with withdrawal symptoms
    • liver disease, e.g. cirrhosis, liver cancer
    • coronary heart disease
    • high blood pressure
    • fetal alcohol syndrome
    • permanent brain damage
  20. Describe and explain the techniques used for the detection of ethanol in the breath, the blood and urine.
    • Include potassium dichromate(VI) in the breathalyser, changes from orange to green as they ozidize the ethanol to ethanal and ethanoic acid
    • Analysis of blood and urine by chromatography: blood or urine is vaporized and injected into a stream of an inert gas (the mobile phase) over the surface of a non-volatile liquid (the stationary phase). A peak at the retention time corresponding to ethanol can be used to confirm its presence in the vapour
    • Absorption of infrared radiation or use of a fuel cell in the intoximeter
  21. Describe the synergistic effects of ethanol with other drugs.
    Increased risk of stomach bleeding with aspirin and increased risk of heavy sedation with any drug that has a sedative effect on the central nervous system
  22. Identify other commonly used depressants and describe their structures.
    • diazepam (Valium®)- seven-membered heterocyclic ring containing carbon and two nitrogen atoms, 2 benzene rings, ketone, Chloro
    •  nitrazepam (Mogadon®)- heterocyclic ring, 2 benzene rings, ketone
    •  fluoxetine hydrochloride (Prozac®)-functions by increasing the levels of serotonin, used in treatment of depression, eating disorders and panic disorders
  23. List the physiological effects of stimulants.
    • help to facilitate breathing by causing relaxation of the air passages and are used in treatment of respiratory infections such as severe bronchitis
    • reduce appetite- used as part of treatment for obesity
    • may cause palpitations or tremors to occur
    • when used in excess, they can cause extreme restlessness, sleeplessness, fits, delusions and hallucinations
  24. Compare amphetamines and epinephrine (adrenaline).
    Amphetamines and epinephrine (adrenaline) are chemically similar in that both derive from the phenylethylamine structure. Amphetamines mimic the effects of epinephrine (adrenaline) and are known as sympathomimetic drugs.
  25. Discuss the short- and long-term effects of nicotine consumption.
    Short-term effects include increased heart rate and blood pressure and reduction in urine output, as well as stimulating effects.Long-term effects include increased risk of heart disease, coronary thrombosis and peptic ulcers.Include also the addictive properties of nicotine and the further risks associated with smoking tobacco.
  26. Describe the effects of caffeine and compare its structure with that of nicotine.
    Caffeine is a respiratory stimulant. When consumed in large amounts it can cause anxiety, irritability and sleeplessness. It is a weak diuretic. Both caffeine and nicotine contain a tertiary amine group
  27. Outline the historical development of penicillins.
    • Fleming noticed that a fungus known as Penicillium notatum had contaminated some of his cultures and discarded them as spoiled however the mould had generated a clear region around it where no bacterial colonies were growing. He concluded that something produced by the mould was inhibiting the bacterial growth
    • Florey and Chain isolated penicillin as the antibacterial agent produced by the mould. Used for the first time in WWII on humans
  28. Explain how penicillins work and discuss the effects of modifying the side-chain.
    • Penicillins work by interfering with the chemicals that bacteria need to form normal cell walls. Modifying the side-chain results in penicillins that are more resistant to the penicillinase enzyme.
    • Different forms of penicillin have been developed by modifying the side chain and these enable the drug to retain its activity even when ingested in pill form.
  29. Discuss and explain the importance of patient compliance and the effect of penicillin overprescription.
    Strict adherence to a recommended treatment regime is necessary for the effectiveness of anti-TB drugs (frequently several drugs are used in combination).The use of penicillins in animal feedstock also contributes to the resistance problem.
  30. State how viruses differ from bacteria
    Viruses differ from bacteria with their more complex cellular structure and ability to survive and reproduce independently from other living cells.
  31. Describe the different ways in which antiviral drugs work.
    Antiviral drugs may work by altering the cell’s genetic material so that the virus cannot use it to multiply. Alternatively, they may prevent the viruses from multiplying by blocking enzyme activity within the host cell.
  32. Discuss the difficulties associated with solving the AIDS problem.
    • Specific proteins on the HIV virus bind to a receptor protein on certain white blood cells (T cells). Because of the ability of the HIV viruses to mutate, and because their metabolism is linked closely with that of the cell, effective treatment with antiviral drugs is very difficult, as is vaccine development.The control and treatment of HIV is exacerbated by the high price of anti-retroviral agents and sociocultural issues.
    • 1. The virus destroys T-helper cells (cells in the immune system that should be defending the body against the virus)
    • 2. The virus tends to mutate very rapidly (patient has to make a response to the new virus)
    • 3. The virus often lies dormant within host cells, so the immune system has nothing to respond to
  33. Describe the importance of geometrical isomerism in drug action.
    • cis- and transisomerism can occur in inorganic complexes and that the two different isomers can have different pharmacological effects.
    • ex: anti-cancer drug cisplatin
  34. Discuss the importance of chirality in drug action.
    The two enantiomers in a racemic mixture of a drug may have very different effects, for example, Thalidomide. One enantiomer of Thalidomide alleviates morning sickness in pregnant women, while the other enantiomer causes deformities in the limbs of the fetus
  35. Explain the importance of the betalactam ring action of penicillin.
    The high reactivity of the amide group within the four-membered ring structure is a result of strain. The ring opens so that the penicillin becomes covalently bonded to the enzyme that synthesizes bacterial cell walls, thus blocking its action
  36. Explain the increased potency of diamorphine (heroin) compared to morphine.
    The polar hydroxyl groups in morphine are replaced by non-polar ester groups, facilitating transport into the non-polar environment of the central nervous system.
  37. Discuss the use of a compound library in drug design.
    Traditionally, a large collection of related compounds are synthesized individually and evaluated for biological properties. This approach is time-consuming and expensive
  38. Explain the use of combinatorial and parallel chemistry to synthesize new drugs.
    Combinatorial chemistry is used to synthesize a large number of different compounds and screen them for biological activity, resulting in a “combinatorial library”. Alternatively, parallel synthesis can produce smaller, more focused libraries. Students should be aware of the importance of solid-phase chemistry.
  39. Describe how computers are used in drug design.
    Three-dimensional models of drugs can be created in silico and molecular modelling software can be used for the virtual development and evaluation of new drugs.
  40. Discuss how the polarity of a molecule can be modified to increase its aqueous solubility and how this facilitates its distribution around the body.
    • The structure of aspiring contains an ester group and a carboxylic acid group attached to a benzene ring. When it is reacted with a strong alkali, it forms a salt in which the carboxylic acid group is convereted into its conjugate base, the acid anion. This increases the aqueous solubility of the compound; formulations containing the salt of the acid are known as soluble aspirin.
    • fluoxetine is not very soluble
    • fluoxetine hydrochloride is more soluble

    Students should be aware of the ability of acidic (carboxylic acid) and basic (amine) groups to form ionic salts, for example, soluble aspirin and fluoxetine hydrochloride (Prozac®).
  41. Describe the use of chiral auxiliaries to form the desired enantiomer.
    A chiral auxiliary is used to convert a non-chiral molecule into just the desired enantiomer, thus avoiding the need to separate enantiomers from a racemic mixture. It works by attaching itself to the non-chiral molecule to create the stereochemical conditions necessary to force the reaction to follow a certain path. Once the new molecule has been formed, the auxiliary can be taken off (recycled) to leave the desired enantiomer. An example is the synthesis of Taxol, an anti-cancer drug.
  42. Describe the effects of lysergic acid diehylamide (LSD)
    • potent hallucinogen that creates distortions of the body and crawling geometric patterns
    • causes impaired judgement, hypertension, dilated pupils, and changes to body temperature and heart rate
    • can cause unpredictable mood swings from euphoria (a 'good trip') to depression and panic (a 'bad trip')
  43. Describe the effects of tetrahydrocannabinol (THC)
    • acts to depress the central nervous system and causes mental relaxation and euphoria 
    • can lead to loss of inhibitions, and an alteration of the perception of time and space
    • palpitations, loss of concentration, light-headedness, weakness and a sense of floating are commonly experienced
  44. Discuss the structural similarities and differences between LSD, mescaline and psilocybin.
    based on a common structure, the indole ring (a benzene ring attached to a five-membered heterocyclic ring containing one nitrogen atom and a carbon-carbon double bond.
  45. Discuss the arguments for and against the legalization of cannabis.
    • Arguments for legalization include the ability of cannabis to offer relief from certain diseases.
    • Arguments against legalization include the possible harmful effects and the possibility of cannabis users moving on to harder drugs.