Symbol/picture cards

Question 1

Give the formula for determining the fraction of total receptors bound with a ligand

Answer 1

Question 2

Recall the hyperbolic concentraiton binding curve of a drug, where would its Kd fall?

Answer 2

Question 3

Recall a sigmoidal receptor binding curve expressed with and without sem-log transformation.

Answer 3

Question 4

Define:

Emax

ED₅₀

Answer 4

Emax: The maximum response achieved by an agonist (drug efficacy)

ED₅₀: The drug dose at which 50% of Emax is achieved (potency)

Question 5

Recall a quantal dose-response curve

Answer 5

• Useful to describe population rather than single individual response to drugs
• Based on plotting cumulative frequency distribution of responders against the log drug dose (may sometimes have a drug that can’t affect 100% of people)

Question 6

Recall the impact of inverse agonist, atagonist and agonist on blood vessel diameter and constitutive receptor activity

Question 7

How is the therapeutic index of a drug determined?

Answer 7

Whether or not something has good therapeutic index depends on what the toxic effect is (eg. headaches vs. death)

In general, a larger TI indicates a clinically safer drug

Question 8

Give the formula for determining volume of distribution (Vd) immediately after bolus injection

Answer 8

Q: Total amount of drug in body (dose)

Co: initial plasma concentration

Question 9

Give the equation for IV bolus pharacokinetics (elimination) with the single compartment model

Answer 9

Question 10

Give the equation for single compartment IV bolus eliminiation half life (T_1/2)

Answer 10

Question 11

Recall the half life graph for a single compartment IV bolus injection.

Answer 11

Question 12

Give the formula for clearance with k_el

Answer 12

Question 13

Give the formula for drug half life with clearance (Cl)

Answer 13

Question 14

A drug has a minimum therapeutic concentration of 2 μg(mL^-1), what dose should Joe receive to achieve teh minimum therapeutic plasma concentration if it has a volume of distribution (Vd) of 20 L?

Answer 14

Question 15

Recall a schematic for two methods of maintaining steady state (Css) without IV

Answer 15

• Repeated dosages
• First large dose (loading phase) then maintenance

Question 16

Why is compliance of drug dosage scheduling so important?

Answer 16

Changing dosing intervals can lead to no effect, or toxic effect.

Question 17

Recall the four most important pharmacokinetic equations

Answer 17

Question 18

Recall the two common transmembrane receptors with intrinsic enzyme activity.

Answer 18

Tyrosine Kinases-containing Receptors - Receptors that have intrinsic catalytic activity (tend to dimerize)

e.g. for growth factors such as epidermal growth factor (EGF).

Tyrosine Phosphatase receptors – Receptors that dephosphorylate tyrosine residues on proteins (don’t tend to dimerize)

Question 19

Recall the two common transmembrane receptors that link to an enzyme activity

Answer 19

Tyrosine Kinase-linked Receptors - Receptors that work through associated proteins
e.g. for cytokines that control the immune response such as the interleukins (ILs).

Receptor Serine/Threonine Kinase e.g TGFβ receptor. More involved in longer term response than G proteins.

Question 20

Recall the guanylyl cyclase receptor

Answer 20

Stimulation modulates: phosphodiesterase (breaks down GTP), PKG and ion channels