Konorev: Intro to Pharmacodynamics

Question 1

Pharmacokinetics

Answer 1

-the effects of the body on drugs

Question 2

Pharmacodynamics

Answer 2

-effects of the drugs on the body

Question 3

In a dose response curve, what two phases are there?

Answer 3

• linear phase
• Plateu phase
• hyperbolic curve

Question 4

How do we change the hyperbolic curve into a sigmoid curve?

Answer 4

• change the x axis to log of dose rather than just dose

- extends the linear phase

Question 5

What id ED50? (effective dose 50)

Answer 5

-the dose of drug that produces 50% of its maximal effect

Question 6

Affinity

Answer 6

-describes how readily and tightly that drug binds to its receptor

Question 7

What is KD

Answer 7

• equilibrium dissociation constant
• drug concentration at which 50% of the drug receptor binding sites are occupied by the drug
• lower Kd= higher affinity, and vice versa

Question 8

Drug selectivity

Answer 8

• determined by drug’s affinities at various binding sites

- more selective drug would affect fewer targets

Question 9

Intrinsic activity

Answer 9

• describes the ability of a drug to change a receptor function and produce a physiological response upon its binding to a receptor
• Example: agonists, but not antagonists

Question 10

Do antagonists change the function of the receptor upon binding?

Answer 10

• no

- there is no intrinsic efficacy

Question 11

What happens to EC50 and Emax with competitive antagonism?

Answer 11

• agonist EC50 increases

- Emax does not change

Question 12

What happens wto EC50 and Emax with noncompetitive antagonism?

Answer 12

• agonist EC50 does not change

- Emax decreases (lower ceiling)

Question 13

How do you find Kd?

Answer 13

• equilibrium dissociation constant

- (L)(R)/(LR)

Question 14

Which drug will have a higher Emax, a partial agonist or a full agonist?

Answer 14

-a full agonist will have a bigger Emax than the partial agonist

Question 15

can a partial agonist cause an opposite effect in the presence of a full agonist?

Answer 15

• yes, so watch out for that
• ex: pindolol
• increases HR when used alone, but in the presence of full agonist, it decreases HR

Question 16

What happens with the receptor when an antagonist binds?

Answer 16

-nothing happens to the receptor, it just gets blocked

Question 17

what is potency related to?

Answer 17

• drug dose
• a lower dose will activate a receptor better
• describes the amoint of drug required to porduce a specific pharmacological effect

Question 18

What is efficacy related to ?

Answer 18

• Bmax
• the number of available receptors available to bind a drug
• the maximal pharmacologic effect that a drug can produce

Question 19

What is a graded response?

Answer 19

• answers the question “How Much?”
• typically represents the mean value within a population or a single subject
• sigmoidal curve

Question 20

What is a quantal response?

Answer 20

• all or none, yes-no, binary responses
• “does the response occur or not?”
• “in how many?”
• used to examine the frequency of a response within a large population
• bell shaped curve if non cumulative
• cumulative will be sigmoid

Question 21

What is a cumulative quantal dose response curve?

Answer 21

-number or % of ppl responding at a dose of a drug and at all doses lower than that dose

Question 22

How do we find therapeutic index?

Answer 22

• TD50/ED50

- the higher the TI, the safer the drug

Question 23

What is the therapeutic window?

Answer 23

-the range of doses of a drug or of its concentration in a bodily system that provides safe and effective therapy

Question 24

What can we find froma cumulative frequency distribution?

Answer 24

-Median effective dose (ED50

Question 25

If there is a drug that is 5x more potent, what is the appropriate dose?

Answer 25

-original dose/5