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Flashcards in Pharmacodynamics 1 Deck (16):
1

Define: Pharmacokinetics

Study of how the body affects the concentration of drug at the active site as a function of time (absorption, distribution, metabolism, excretion) What the body does to the drug

2

Define: Pharmacodynamics

Study of how target cells respond to the delivered concentration of drug. What the drug does to the body

3

Receptors as drug targets are:

Signal transduction systems
specific to ligands
stereospecific
obey mass action principles

4

Receptors as drug targets can:

determine dose and effect relationship
determine drug selectivity
mediate action of agonist and antagonists

5

Receptors for lipid soluble drugs

Enzymes, transcription factors, structural proteins. These take more time to act, but effects persist for hours or days.

6

Transmembrane receptor kinase action

extracellular hormone-binding domain and cytoplasmic enzyme domain, dimerization upon ligand binding = activation of tyrosine kinase activity, leading to downstream to regulated by down-regulation - removal from cell surface

7

How does the glucocorticoid receptor work?

Steroid causes the displacement of heat shock protein 90 (hsp90) allowing the transcription activating domain to become active

8

Cytokine receptors action

same as TRK, except no intrinsic kinase activity. Instead, signal transduced by associated JAK-STAT signalling

9

Ligand-gated channels

Mimic endogenous ligand. Very rapid response - milliseconds

10

Voltage-gated channels

Allosteric binding. Very rapid response

11

G-protein coupled receptors

7 transmembrane or serpentine receptor. GTP-G protein complex acts on second messenger. Either adenylyl cyclase or phospholipase C

12

What do antiacids and osmolarity agents have in common?

They don't act on receptors, but directly on ionic milieu

13

Rapid desensitization

decreased ability of receptors to respond to stimulation by the drug - often though g-protein phosphorylation

14

Resensitization

recovery of receptor after agonist is removed

15

Down regulation -

Removal and degradation of receptor upon repeated or persistent drug-receptor interaction, cannot resensitize

16

Dissociation constant

Concentration at which 50% of receptors are occupied.