Lecture 4

Question 1

pharmacodynamics

Answer 1

what the drug does to the body

Question 2

pharmacokinetics

Answer 2

what the body does to the drug

Question 3

how does pharmacokinetics work

Answer 3

The branch of pharmacology that studies the behaviour of drugs as they move into, around and out of the body.

Question 4

ADME process

Answer 4

• absorption
• distrabution
• metabolsim
• excretion
• urine

Question 5

plasma concentration time profile or curve

Answer 5

• blood concentration in blood against time
• helps define the therapeutic window
• most drugs produce dose dependent plasma concentration time profiles
• width of the window shows how safe a drug is for patients

Question 6

ADME 1- Absorption

Answer 6

• Drug Absorption is process
  whereby ingested drug molecules relocate from interior of GI-tract into the portal blood (drains from gut into the liver)

Question 7

reasons for poor absorption

Answer 7

1- drug is too big (>600g/mol)
2- drug is not greasy enough 
3- drug carries a charge 
4- drug is metabolised in gut wall
5- drug is pumped back into gut

Question 8

ADME 2- Distrabution

Answer 8

• where drugs go in the blood stream depends on their physicochemical properties
• drugs remain in the blood mainly
• other drugs pentrate tissues
• getting drugs into the brain is harder because of the blood brain barrier

Question 9

Hydrophilic drugs

Answer 9

• not vulnerable to protein binding

- most drug ciculates in blood as unbound or free drug

Question 10

Lipophilic Drugs

Answer 10

• vulnerable ot protein binding
• most drugs cicruclates in blood while bound to plasma proteins
• 10% bound drug

Question 11

Lipophilic drugs

Answer 11

• vulnerable to protein binding
• most drugs circulates in blood while bound to plasma protein
• 90% bound drug

Question 12

ADME 3- Metbabolism

Answer 12

the chemical alteration of drugs by drugs metabolising enzymes in the body.

• drugs eneter the body if they are lipphilic bu they might accumulate in body tissues
• the body converts them into water soluble metabolites
• the body expresses the hundred of drug metabolsiing enzymes
• protect us against driugs, pollutants ect

Question 13

what happens to drugs when they are metabolised

Answer 13

• reduces activity of drugs
• some drugs are inactive until metabolised (pro drugs)
• some drugs metabolites are toxic

Question 14

ADME - excrection

Answer 14

“The permanent removal of
unchanged drugs from the
body via body fluids and secretions, expired air or tissue shedding.
- 25-30% of current medicine is not metabolsied
- these drugs are excreted unchanged by the kidneys to the urine
- other drugs are excreted unchnaged into the bile
- other minor routes of include breast milk,expired air, sweat
- membrane transporters act as excretory drug pumps into urine, bile, milk ect

Question 15

Examples of hydrophilic drugs

Answer 15

• penicillins
• cephalosporins
• gentamycin
• metformin

Question 16

Examples of lipohilic drugs

Answer 16

• morphine
• diazepam
• chlorpromazine