Paper 3

Question 1

Lethal dose vs. toxic dose

Answer 1

LD50: amount/dose that kills 50% of the
population
Lethal - animal trails
Toxic- human studies

Question 2

Therapeutic index in animal studies vs. therapeutic index in humans

Answer 2

Animals: amount that causes death
Human: toxicity amount

Question 3

maximum bioavailability

Answer 3

Intravenous

Question 4

State the meaning of the term therapeutic window.

Answer 4

range of dosages between effective level and toxic level

Question 5

Suggest why a narrow therapeutic window may be a problem.

Answer 5

need close medical supervision

Question 6

side-effects

Answer 6

undesired effects of drug

Question 7

Advantage to oral drugs

Answer 7

easily taken

Question 8

disadvantage to oral drugs

Answer 8

only small fraction of drug absorbed

Question 9

List three methods, other than orally, that can be used for the administration
of a drug.

Answer 9

intravenous, skin patches, eye/ear/nose drops

Question 10

Bioavailability

Answer 10

fraction of the administered dosage that reaches the bloodstream

Question 11

Factor affecting bioavailability

Answer 11

1. Method of administration
2. Solubility of the drug
3. Functional groups
   More polar and contains functional groups that can hydrogen bond to water will be more soluble in water- > higher bioavailability

Question 12

Tolerance

Answer 12

repeated doses of a drug result in smaller physiological effects

Question 13

Aspirin

Answer 13

mild analegesic

Question 14

State other uses of aspirin

Answer 14

blood thinner, lowers risk of heart attacks

Question 15

Outline how the bioavailability of aspirin may be increased

Answer 15

intravenous

Question 16

How does penicillin combats bacterial infections

Answer 16

ring breaks and cells cannot reproduce

Question 17

Consequence of prescribing antibiotics such as penicillin unnecessarily

Answer 17

leads to resistance of bacteria

Question 18

State how penicillin may be modified to increase their effectiveness

Answer 18

modify R group

Question 19

Mild analgesics function

Answer 19

intercept the pain at the source by preventing the synthesis that causes pain

Question 20

why is aspirin slightly soluble in water

Answer 20

Non polar @ benzene
Polar contains COOH

Question 21

Difference in melting point compared to that of pure aspirin

Answer 21

sample is impure and fewer intermolecular forces

Question 22

Opiates

Answer 22

strong analgesic

Question 23

opiates function

Answer 23

prevents the transmission of pain impulses n the brain (rather than at the source)

Question 24

why is codeine more widely used than morphine as an analgesic

Answer 24

codeine has a wider therapeutic window

Question 25

How can codeine be synthesized from morphine

Answer 25

react with methyl iodide

Question 26

Why are opiates addictive

Answer 26

gives a feeling of pleasure that a person craves and alters the structure of brain cells

Question 27

Why diamorphine passes more readily than morphine through the blood-brain barrier

Answer 27

diamorphine has ester and morphine has hydroxyl diamorphine ester groups - less polar

Question 28

reagents used to prepare diamorphine from morphine

Answer 28

ethanoic/acetic anhydride

Question 29

Why is codeine available without a prescription in some countries while morphine is administered under strict medical supervision

Answer 29

morphine has a smaller therapeutic window

Question 30

SImilar functional groups in methadone and diamorphine

Answer 30

phenly

Question 31

Different function groups in methadone and diamorphine

Answer 31

ester

Question 32

withdraw symptom an addict may have

Answer 32

feeling depressed

Question 33

How prilosec regulates pH in the stomach

Answer 33

PPI prevent cid from traveling to stomach

Question 34

How zantac reduces stomach acid production

Answer 34

prevent parietal cells from producing acid

Question 35

histamine

Answer 35

a chemical transmitter that stimulates stomach acid production by binding at H2 receptors.

Question 36

way to reduce stomach acid secretion

Answer 36

block the histamine- H2 interaction

Question 37

H2 - receptor antagonists

Answer 37

drugs that prevents histamine binding to H2 receptors and triggering acid secretion

Question 38

PPI

Answer 38

directly prevent the release of acid into the stomach

Question 39

PPI

Answer 39

Proliosec

Question 40

Antacids

Answer 40

weakly basic compounds that neutralize the acid

Question 41

Antacids: Metal Hydroxides

Answer 41

Acid + Base -> H20 + Salt

Question 42

Anatacids carbonates and Hydrogen Carbonates

Answer 42

Carbonate + Acid -> H20 + CO2 + Salt

Question 43

Potassium hydroxide also neutralizes hydrochloric acid . Can it be used as an antacid?

Answer 43

KOH is a strong base and any group 1 metal + base creates a strong base and strong bases can burn human tissue

Question 44

2 functional groups in zanamivir

Answer 44

ether, carboxyl

Question 45

Distinguish between bacteria and viruses

Answer 45

Bacteria: is a single cell organism where virus is not Virus: Lack cell structure where bacteria does not

Question 46

Antiviral

Answer 46

prevents virus from leaving cell (blocking neuraminidase)

Question 47

Two difficulties associated with the development off drugs for effective treatment of AIDS

Answer 47

HIV mutates HIV detroyes helper T Cells

Question 48

How does tamiflu work against the flu?

Answer 48

blocks the neuraminidase enzyme, which prevents the virus from leaving host cell and so it cannot infect other cells

Question 49

Antiretroviral drugs (ARVs)

Answer 49

1. change cell membrane that inhibits the entry of virus into the cells 2. prevents virus replication 3. prevents viruses from leaving the cell (after reproducing)

Question 50

one difficulty with synthesizing tamiflu from star anise

Answer 50

low concentration in plant

Question 51

low environmental impact of most medical nuclear waste

Answer 51

low radioactivity and exist for a short period of time

Question 52

environmental effect of antibiotics

Answer 52

resistance in bacteria

Question 53

how green chemistry can solve the environmental problems

Answer 53

use water as a solvent