Parkinsons

Question 1

Dopamine hypothesis

Answer 1

increase dopamine in mesolimbic = positive

decrease dopamine in mesocortical = negative

Question 2

LSD and mescaline are 5HT agonist causing hallucinations

5HT2A receptor blockade - main MOA in atypical antipsychotics (clozapine)

Answer 2

serotonin hypothesis

Question 3

phencyclidine and ketamine inhibit NMDA causing psychosis in schizo

hypo NMDA activates diminished gabanergic activity, which causes disinhibition of neuron fxn, leading to hyper stimulation through non NMDA receptor

NMDA activity decreases in schizo

Answer 3

glutamate hypothesis

Question 4

psychotic disorders and addiction are partly explained by increase DA in this pathway
drugs that increase DA fxn - increase reinforcement and at high doses, may cause psychosis
DA antagonists - decrease cognitive fxn

Answer 4

mesolimbic and mesocortical

Question 5

parkinson dz, decrease DA neurons tract leads to increase Ach activity - EPS dysfxn
DA receptor antagonists- pseudo Parkinsonism (reversible)
DA agonists may cause dyskinesias

Answer 5

nigrostriatal

Question 6

anterior pituitary release DA - increase prolactin
DA agonists - hyperprolactemia
DA antagonist cause endocrine dysfxn, gynecomastia, amenorrhea/galactorrhea

Answer 6

tuberinfundibular

Question 7

eating behavior

Answer 7

medullary periventricular

Question 8

may regulate sex behavior

Answer 8

incertohypothalamic

Question 9

activation of DA receptor - increase emesis

DA agonists are emetic and DA antagonist are antiemetic

Answer 9

chemoreceptor trigger zone

Question 10

bradykinesia, muscle rigidity, resting tremor, gait impairment
degeneration of nigrostriatal DA tracts with imbalance between DA (decrease) and Ach (increase)

Answer 10

parkinsons

Question 11

strategy for treating parkinsons

Answer 11

1) restore normal dopamine levels
2) reduce Ach activity at muscle receptor in striatum
3) surgery: deep brain stim

Question 12

cofactor for dopa decarboxylase, so increase peripheral metabolism of levodopa decrease its effectiveness

Answer 12

vitamine B6

Question 13

receptor unregulated in parkinsons

Answer 13

D2

Question 14

ergots can cause

Answer 14

fibrosis

• pulmonary
• retropertoneal

Question 15

prodrug converted to DA by aromatic acid decarboxylase

given with cardiodopa = synemet (preventing peripheral conversion)

Answer 15

levodopa

Question 16

SE: dyskinesias, on off effect, psychosis, hypotension, vomiting

Answer 16

levodopa

Question 17

enters brain by L amino acid transporter but DA does not

Answer 17

levodopa

Question 18

response to L DOPA is reduced years later
wearing off: drug [ ] is low between doses
on off phenom: unrelated to timing of doses

Answer 18

levodopa

Question 19

COMT converts L DOPA to 3 O methyldopa, partial agonist at DA receptor
inhibit COMT and enhance LDOPA uptake and efficacy
increase DA

Answer 19

tolcapone

entacapone

Question 20

hepatotoxic
has both peripheral and central action
inhibits COMT

Answer 20

tolcapone

Question 21

inhibits COMT

only peripheral action

Answer 21

entacapone

Question 22

MAOB selective inhibitors
used in Parkinsons of people less than 60
effective in MPTP induced Parkinsonism (environmental)

Answer 22

selegiline

rasagiline

Question 23

initial treatment and adjunct to LDOPA

SE: dyskinesia, psychosis, insomnia

Answer 23

selegiline

rasagiline

Question 24

D3 agonist scavenges H2O2

Answer 24

pramipexole

Question 25

Both non ergot D agonists

preferred D2 agonists in treatment of Parkinsons

Answer 25

pramipexole

ropinirole

Question 26

ergot alkaloid
D2 agonist

Tx: hyperprolactinemia, acromegaly, parkinsons

Answer 26

bromocriptine

Question 27

used to tx inf A
increases DA release

SE: lived reticularis and atropine like effect

Answer 27

amantadine

Question 28

action: decrease tremor and rigidity but have little effects on bradykinesia

SE: dry mouth, urinary retention, constipation

Answer 28

benztropine
trihexyphenidyl
Diphenhydramine