PHARM - Antipsychotics Flashcards
discuss the pathogenesis behind
- positive schizophrenia symptoms
- negative schizophrenia symptoms
both due to abnormal dopamine neurotransmission from dopraminergic neurons
- positive symptoms: overactivity of mesolimbic pathway
- negative symptoms: underactivity of mesocortical pathway
what major side effects can result from blockage of D2 receptors?
- extrapyramidal system (EPS) AEs
- hyperprolactinemia
what are the EPS adverse affects?
- parkinson like symptoms
- akathisia
- acute dystonia
- tardive dyskinesia
acute dystonia
- early or late EPS effect?
- presentation
- early effect
- presentation: severe spasm of back, neck, face and tongue
- if progression to larynx → respiration impairment
parkinsonism
- early or late EPS effect?
- presentation
- early EPS effect
- presentation: bradykinesia
- resting tremor
- abrormal gait - stooped, shuffling
- ridigity - often at elbow
- facial weakness - mask-like, drooling
akasthia
- early or late EPS effect?
- presentation?
- early EPS effect
- presentation: pacing & squirming d/t an uncontrollable need to move
tardive dyskinesia
- early or late EPS effect?
- presentation
- late effect
- presentation: twisting, writhing, worm- like movements of the
- tongue
- face
discuss the mechanism of D2-blockage induced hyperprolactinemia
blockage of D2 receptors in the tuberoinfundibular pathway → no release of DA onto PRL-secreting neurons → no inhibition of PRL release → hyperprolactinemia
which anti-dopaminergic AE is due to
- blockage of the infundibular pathway?
- blockage of the nigrostratial pathway?
- infundibular: hyperprolactinemia
- nigrostriatal: akathisia (an EPS)
review the AE that results from histamine blockage
drowsiness / sedation
review the AEs that result from alpha-1 adrenergic receptor blockage
orthostatic hypotension
(resulting from blockage of compensatory vasoconstriction when patient stands)
review the AEs that result from muscarinic blockage
- dry mouth
- blurred vision
- urinary retention
- constipation
- aggravation of glaucoma
- tachycardia
typical anti-psychotics
- include which drugs?
- clinical uses?
- MOA?
- PK
- AE/CI?
- drugs: haloperidol, chlorpromazine
- clinical uses: schizophrenia - both positive and negative symptoms
- MOA: block D2 receptors + cross reactive with H1, M1 & alpha-1 receptors
- PK:
- narrow therapeutic range
- various potencies, which dictate AE profile
- AE:
- high potency = AEs from D2 blockage
- EPS side effects
- hyperprolactinemia
- low potency = AEs from cross reactiivty
- anti-histaminergic - drowsiness
- anti-a1 adrenergic - orthostatic hypotension
- anti-cholinergic - u should know this by now
- QT interval prolongation
- neuroepileptic syndrome
- high potency = AEs from D2 blockage
constrast the adverse effect profiles of low potency vs high potency typical anti-psychotics
(haloperidol, chlorpomazine)
high potency: D2 predominante
- EPS: tardive dyskinesia, akathisa, dystonia, parkinsonism
- hyperprolactinemia
low potency: H1 / a1 / M1 predominate
- drowiness (H1)
- orthostatic hypotension (a1)
- dry mouth, blurred vision, urinary retention / constipation, glaucoma, tachycardia (M1)
both = prolonged QT, neuroepileptic
summarize the AEs of high potency typical anti-psychotics
(haloperidol, chlorpromazine)
EPS & hyperprolactinemia > drowsiness, orthostatic hypotension, anticholinergic affects
+ prolonged QT, neuroepileptic syndrome