Clinical Pharmacology

Question 1

what is pharmacodynamics?

Answer 1

what the drug does tothe body
i.e. The action of a drug:
What does it target?
What is the response?

Question 2

what is pharmacokinetics?

Answer 2

what the body does to the drug
i.e. Movement of drug within the body:
Where does the drug go?
Therapeutic plasma concentration

Question 3

what is clinical pharmacology?

Answer 3

the study of clinical effects of a drug on patients

Question 4

what interacting consideration do you need to take into account when using theraputics?

Answer 4

1. underlying disease factors Importance of diagnosis leads to specific therapeutics goals
   But there can be a case for symptomatic therapy
2. drug data
   efficacy and safety, licensed, off-lable, formulation
3. owner needs
   financial, physical ability
4. paitent factors
   can it be administered, special situations (pregnancy, laction, elderly)
5. practice
   corporate practices, drug buying power,shelfstock and turnover
6. compliance
   training and eductaion, theraputic option (long-term)

Question 5

what are the 6 molecules that drugs target?

Answer 5

• receptors
• ion channels
• structural proteins
• enzymes
• carrier molecules
• DNA

Question 6

describe the agonist does response curve

Answer 6

Question 7

explain what a partial agonist is?

Answer 7

will only elicit a partial response,

Question 8

what is potency?

Answer 8

the amount of drug required to produce 50% of its maximal effects (ED50).
used to compare drugs within a chemical class

Question 9

what is efficacy?

Answer 9

the maximun theraputic response that a drug can produce (eg morphine vs buprenorphine)

Question 10

what is drug specificity?

Answer 10

the capacity of a druf to cuase a particular action on a popultaion

Example: a drug with absolute specificity of action might decrease or increase the specific function of a given target. It must do either, but not both.

Question 11

what is drug selectivity?

Answer 11

relates to a drugs ability to target only a selective population ie cell/tissue/signally pathway, protein ect in preference to others

Example: Atenolol is a B1-selective adrenoreceptor antagonist, while propranolol is a non-selective B-antagonist

Question 12

how do you calculate the therapeutic index of a drug?

Answer 12

Question 13

how do competative antagonists work?

Answer 13

Competitive antagonists compete with agonists for the receptor binding site
Antagonist binds to receptor in such a way as to prevent agonist binding

Competitive antagonism is surmountable – additional agonist can overcome the receptor blockade.

Question 14

how do non-competative antagonsits work?

Answer 14

Either bind to a different receptor site or block “post” binding chain of events (i.e. act “downstream” of the receptor)

Question 15

what dose a competative antagonist do to the agonist dose response curve?

Answer 15

shifts the agonist dose responce curve to the right in parallel

Question 16

in what 4 ways can drugs act on enzymes?

Answer 16

• competative inhibitor binds to catalytic (active) site - normal reation inhibited
• non-competative inhibitor - binds to enzyme not at the catalytic site and the shape of the catalytic site changes preventing substrate binding
• false substrate - will bind to catalytic site and will produce an abnormal metabolite
• prodrug - bide to catalytic site, are converted and the active drug is produced

Question 17

what is tachyphylaxis?

Answer 17

loss of target sensitivity
the effect of a drug is decreased when given continuously or repreadedly (normally agonists)

Question 18

why does tachyphylaxis occur?

Answer 18

• Change in receptors (become resistant to drug stimulation/conformational changes)
• Loss of receptor number
• Exhaustion of mediators
• Increased metabolic degradation of the drug
• Physiological adaptation (crosstalk between body systems, one takes over)
• Drug transporters (active extrusion of the drug)