Antipsychotics

Question 1

typical antipsychotics are best for treating symptoms associated with which brain pathway? what are the symptoms?

Answer 1

mesolimbic dopamine pathway

positive symptoms - delusions, agitation, hallucinations and disorganized thinking

blocks D2 receptors

Question 2

what are the affects of blocking D2 receptors in the mesolimbic dopamine path?

Answer 2

worsens negative symptoms

Question 3

what is the effect of blocking D2 receptors in the nigrostriatal pathway?

Answer 3

extrapyramidal symtoms

parkinsonism symptoms

Question 4

blocking D2 receptors in tuberoinfundibular pathway has what type of affect?

Answer 4

prolactin release

Question 5

what are the indications for treating with typical antipsychotics?

Answer 5

schizophrenia

drug-induced psychosis

manic phase of bipolar I disorder

nausea, vomiting, gastroparesis - metaclopramide

tourettes - haloperidol and pimozide

Question 6

sedation, urinary retention, extrapyramidal symptoms, akathisia (leg twitching) menstrual irregularities, tardive dyskinesia and neuroleptic malignant syndrome are all symtoms of toxicity with what type of drugs?

Answer 6

typical antipsychotics

Question 7

what is tardive dyskinesia?

Answer 7

decreased DA release leads to upregulation of receptors

this effect can happen months to years later

rabbit syndrome - tongue protrusion, lip-smacking and abnormal movements

for this reason it is best to start with the lowest dose and asses

Question 8

what is neuroleptic malignant syndrome

Answer 8

muscle rigidity, loss of consciousness, tachycardia, high fever, diaphoresis and elevated creatine kinase

Question 9

how do you treat NMS?

Answer 9

discontinue drug and provide supportive care

give dantrolene and brobromocriptine

Question 10

dantrolene

Answer 10

treatment for NMS and malignant hyperthermia

muscle relaxant

binds ryanodine receptor and prevents release of calcium from the sarcoplasm

Question 11

chlorpromazine

Answer 11

typical antipsychotic

low potency

high blockade of muscarinic, histamine and alpha1

corneal deposits

Question 12

thioridazine

Answer 12

typical antipyschotic

low potency, most muscarinic, histamine and alpha1 blockade

high QT interval

Question 13

which typical antipsychotics have high potency?

Answer 13

fluphenazine and haloperidol

most D2 blockade

Question 14

thioridazine

Answer 14

typical antipsychotic

causes pigment retinopathy

Question 15

how do you treat typical antipsychotic toxicity?

Answer 15

treat dystonia and parkinsonism with anticholinergics - benztropine, diphenhydramine

amantadine

treat akathisia with propranolol

Question 16

benzotropine - what is ti? how does it work? what is it used for?

Answer 16

muscarinic blocker

prolongs dopamine levels and helps with tremor associated with D2 antagonists

other drug - trihezyphenidyl

Question 17

muscarinic block toxicity effects

Answer 17

dry eyes, dry mouth, dry skin, constipation

hyperthermia, tachycardia

confusion, delirium, and hallucination

Question 18

explain the serotonin hypothesis about schizophrenia

Answer 18

It is thought there is a connection between psychosis and serotonin because LSD mimics psychotic symptoms.

serotonin inhibits the release of dopamine in the nigrostriatal pathway which decrease extrapyramidal symptoms

5-HT2A block in the tuberoinfundibular pathway decrease release of prolactin

the block of 5-HT2A in the mesocortical pathway increases dopamine which improves negative symptoms

blocking 5-HT2A does not increase dopamine levels in the mesolimbic pathway

Question 19

how do atypical antipsychotic work?

Answer 19

blocks 5-HT2 and to a lesser extent dopamine receptors

the increase in DA release relieves negative symptoms or psychosis with fewer EPS and hyperprolactinemia

they all prolong QT interval

Question 20

aripiprazole

Answer 20

atypical antipsychotic

partial D2 and 5-HT1a agonist nad 5-HT2a antagonist

used in bipolar disorder and for irritability in autism

dec DA in mesolimbic, inc DA in mesocortical

Question 21

clozapine

Answer 21

atypical antipsychotic

binds D1 and alpha1, then 5-HT2A

causes weight gain - 5-HT2c block

can cause agranulocytosis

Question 22

olanzapine

Answer 22

atypical antipsychotic

less ANS effects but blocks D3 and D4

causes weight gain and sedation

approved for combination with fluoxetine to treat mania

Question 23

quentiapine

Answer 23

D2 blocker but binds for a short time

miminal muscarinic block, block H1 and alpha1 - heavily sedation

Question 24

risperidone

Answer 24

hypotension from alpha1 blockade

increased prolactin, hyperlipidemia and hyperglycemia

Question 25

paliperidone

Answer 25

active metabolite of risperidone

Question 26

ziprasidone

Answer 26

blocks 5-HT and NE reuptake

causes skin reaction and eosinophilia