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Flashcards in CNS N27 Deck (63)
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1

Major site for drug toxicity

CNS

2

Empirical approach to drugs

stumble upon a drug that treats symptoms, leads to research on mechanism of underlying disease

3

Rational approach to drugs

know mechanism of disease, develop drugs to treat disease

4

Lipophilic drugs for CNS

brain is 50% fat, so most drugs are lipophilic

5

Brain receives _____ of cardiac output

high percentage

6

Blood Brain Barrier

tight junctions of endothelial cells + foot pedicels of astrocytes

7

Blood Brain Barrier inhibits particle diffusion for which 3 characteristics

Size (< 1000)
Charge (neutral)
Metabolic susceptibility (not metabolized by MAO and COMT)

8

Drugs mainly cross the BBB by

simple diffusion; they are small (<1000), uncharged, lipid soluble, resistant to metabolic breakdown

9

2 types of cells found in the brain

Glia and Neurons

10

Glia

support neurons + complex role

11

Neurons

processing of information; drugs work by altering neuronal function

12

Electrical Conduction

along cell surface and axon

13

Transmission

across synapses via neurotransmitters

14

3 types of signal transmission

Adenylate Cyclase (cAMP)
Phosphoinositide (IP3)
Alteration of intracellular ion conc. (Na, Ca, K , Cl)

15

Agonist

drugs that mimic the action of a transmitter

16

Antagonist

drugs that block the receptor

17

Enhancers of reducer drugs

enhance or reduce the effects of transmitters

18

Example of an agonist

Beta-agonist that mimics epinephrine to increase the rate or force of contraction

19

Example of an antagonist

Beta-antagonist (propranolol) competitively blocks the epinephrine receptor and prevents actions of epinephrine and other agonists

20

GABA receptor mechanism

GABA binds receptor --> Cl channels open --> influx of Cl --> hyperpolarization --> decreased neuronal firing

21

Benzodiazepines

used in anxiety, as sedative, anticonvulsant, muscle relaxant; bind a distinct receptor on the Cl channel and enhance the effect of GABA

22

Barbituates

may also enhance GABA

23

Dopamine Mechanism

synthesized from tyrosine, AP --> release of DA into cleft--> effect in target cell--> terminated by reuptake

24

I-DOPA effect Dopamine by

effecting the uptake and synthesis (increasing DOPA action)

25

Amphetamines effect Dopamine by

stimulating release

26

Cocaine effect Dopamine by

preventing reuptake

27

Reserpine effect Dopamine by

interferes with storage

28

MAO inhibitors effect Dopamine by

preventing breakdown of DA

29

Bromocryptine

Agonist to the postsynaptic receptor

30

Haloperidol

antagonist to the postsynaptic receptor