Antipsychotic drugs Flashcards
what is schizophrenia
chronic psychosis with deterioration of functional capacity
positive symptoms of schiz
hallucinations
delusions
disorganized speech
abnormal precense
negative symptoms
avolition(no motivation) algoia (poverty of speech) anhedonia (inability to feel pleasure) blunted effect absence of normal characteristics
what is the mechanism of schiz
too much mesolimbic dopamine causes postive symptoms
low dopamine in the mesocortical pathway causes negative symptoms
what is the mesolimbic system
ventral tegmental area activates nucleus accumbens through dop2
what is the mesocortical system
ventral tegmental area activates prefrontal cortex through dop1
how do most antipsychotics work
block d2 dopamine receptors relieveing postive symptoms
what do atypical antipsychotics work on
inhibit dopamine 1 and 2 relieving both positive and negative symptoms
examples of typical antipsychotics
chlorpromazine
fluphenazine
haloperidol
thiothixene
what are the adverse effects caused by
receptor non selectivity
blockade of non-mesolimbic d2 dopaminergic pathways
what are the adverse effects caused by receptor non-selectivity
antimuscarinic
alpha1 adrenergic blockade
histamine blockade
what is the nirgrostriatal pathway
substantia nigra activates striatum through dop D2 to coordinate voluntary movement
how do antipsychotics effect the nigrostriatal pathway
block d2 causing extrapyramidal side effects
what are the extrapyramidal side effects
parkinsons
akathisia (motor restlessness)
acute dystonic reactions
tardive dyskinesia
what is the tuberoinfundibular pathway
hypothalamus inhibits pituitary prolactin secretion through D2
how do antipsychotics affect the tuberoinfundibular pathway
block d2 causing increase prolactin production
side effects of blocking the tuberoinfundibular pathway
women- lactation ammenorrhea infertility
men- lactation impotence decreased libido gynecomastia
advantages of atypical antipsychotics
reduced d2 affinity so less extrapyrimidal side effects
also blockes 5ht2 receptors which decreases negative symptoms
how do atypical treat the negative symptoms
inhibits serotonin receptor which inhibits D1 so increases the mesocortical dopamine
what are some drug interactions
other sedatives
metoclopramide
SSRI antidepressants
antimuscarinics
dominant adverse effects of atypical antipsychotics
weight gain
hyperglycemia
