1. Principle Targets

Question 1

Why do dentists need to understand drugs?

Answer 1

• to use and prescribe ratioanlly
• dental patients may already be taking drugs
• be up to date with pharmacology and therapeutics
• principals stay the same when individuals come and go

Question 2

What is pharmacology?

Answer 2

• what the drug does to the body
• what the body does to the drug

Question 3

Define ‘pharmacodynamics’

Answer 3

the effects of a drug on the body

Question 4

What falls into pharmacodynamics?

Answer 4

• molecular interactions by which drugs exert their effect (targets for drug action, how drugs act at target, how drug produces action)
• influence of drug conc on magnitude of response (graph representation, therapeutic vs toxic effects)

Question 5

What does pharmacodynamics let us do?

Answer 5

• determine appropriate dose range for patients
• compare effectiveness and safety of one drug to another

Question 6

Define ‘pharmacokinetics’

Answer 6

what the body does to a drug

Question 7

4 divisions of pharmacokinetics

Answer 7

• absorption
• distribution
• metabolism
• excretion

Question 8

What does pharmacokinetics let us do?

Answer 8

• design and optimise treatment regiments for people based on route of administration, frequency of administration and duration of treatment

Question 9

If a woman is itchy and sneezing, you diagnose hayfever. What questions arise for pharmaco kinetics or dynamics?

Answer 9

for dynamics
- why is the drug called antihistamine, where in nose does it work and is the nose the sole location of action?
For kinetics
- taken as a tablet so how does it get to nose, if symptoms continue, why does she have to take another

Question 10

Histamine is released from … when triggered by …

Answer 10

• mast cells
• allergy

Question 11

Why do you need to take an antihistamine every day to maintain effects?

Answer 11

• absorbed and excreted through kidneys
• conc of antihistamine reduced until another tablet taken

Question 12

2 sources of drugs

Answer 12

• naturally occurring
• synthetic

Question 13

Explain naturally occurring sources of drugs

Answer 13

• previously main source (plants)
• imp source of new drugs like taxanes - anti cancer agents in yew tree bark

Question 14

Explain synthetic sources of drugs

Answer 14

• current main source
• can be totally synthetic or identical to naturally derived compounds e.g insulin (identical) or codeine (derived)

Question 15

Define ‘biologics’

Answer 15

• naturally derived (natural within body) but synthetic products (can be generated outside body) e.g growth hormones or antibodies

Question 16

2 ways drugs can interact with targets

Answer 16

• on shape (lock and key)
• charge distribution (type of bonds holding drug to target)

Question 17

List bonds from weakest to strongest

Answer 17

• van der Waal’s
• hydrogen bonds
• ionic interactions
• covalent bonds

Question 18

Explain Van der Waal’s forces

Answer 18

• shifting electron density in a molecules results in generation of a transient pos or neg charge
• react with transient areas of opposite charge in other molecules

Question 19

Explain hydrogen bonds

Answer 19

• hydrogen atoms bonded to oxygen or nitrogen become more positively polarised
• these bond with more negatively polarised atoms e.g oxygen

Question 20

Explain ionic bonds

Answer 20

• atoms with an excess of electrons (negatively charged)
• attract to atoms with a deficiency of electrons (positively charged)

Question 21

Explain covalent bonds

Answer 21

two bonding atoms share elctrons

Question 22

4 considerations taken when looking at drugs binding with targets. Which are about shape and which about charge?

Answer 22

• hydrophobicity (how much it likes water)
• ionisation of drug (pKa)
  (above at charge)
• conformation of target
• stereochemistry of drug molecule
  (above are shape)

Question 23

Most drugs are weak …

Answer 23

bases or acids

Question 24

Most drugs are weak bases or acids. What does this mean for them binding?

Answer 24

• exist in ionised form
• how charged they are affects target site binding
• some target sites only bind un-ionised molecules, some prefer ionised molecules

Question 25

4 targets for drug action

Answer 25

• receptors
• ion channels
• enzymes
• carrier molecules

Question 26

Define ‘receptors’

Answer 26

targets for endogenous transmitters e.g neurotransmitters and hormones

Question 27

Define ‘enzymes’

Answer 27

biological catalysts which facilitate biochemical reactions

Question 28

Define ‘ion channels’

Answer 28

pores which span membranes to allow selective passage of ions

Question 29

Define ‘carrier molecules’

Answer 29

transport ions and small organic molecules across cell membranes

Question 30

Example of a receptor as a target for drug action

Answer 30

• B2 adrenoreceptor
• salbutamol
• for asthma

Question 31

Example of an ion channel as a target for drug action

Answer 31

• voltage gated sodium channel
• lidocaine
• local anaesthetic

Question 32

Example of an enzyme l as a target for drug action

Answer 32

• cyclooxygenase
• aspirin
• analgesic

Question 33

Example of a carrier molecule as a target for drug action

Answer 33

• proton pump
• omeprazole
• anti-ulcer

Question 34

3 drugs which act due to their physico-chemical properties

Answer 34

• antidotes
• antacids
• laxatives

Question 35

How do antacids work?

Answer 35

• neutralise too much acid with alkali

Question 36

Example of a substance in antacid

Answer 36

aluminium hydroxide

Question 37

Antidotes are effective because … for example …

Answer 37

• adds the chemical product that’s missing in overdose
• acetylcysteine to treat paracetamol overdose

Question 38

Example of a laxative and how it works

Answer 38

• lactulose
• osmotic so adds water to faeces