antipsychotics Flashcards
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DSM-5 Criteria for
Schizophrenia
positive Symptoms of Schizophrenia
negative Symptoms of Schizophrenia
cognitive symptoms of Schizophrenia
Proposed Pathophysiology of
Schizophrenia
*
- dopamine theory
Dopaminergic Pathways
Nigrostriatal (A9)
Mesolimbic (A10)
Mesocortical (A10)
Tuberoinfundibular
Nigrostriatal (A9) function
EP system - movement
mesolimbic function
arousal, memory,
motivation
mesocortical function
cognition,
communication,
social function,
response to stress
tuberoinfundibular function
regulates prolactin
release
Uses for Antipsychotics
* FDA Approved Indications
– Schizophrenia
– Bipolar Disorder
– Adjunctive Therapy in Major Depressive Disorder
– Autism Spectrum Disorder
off label Uses for Antipsychotics
– Anxiety Disorders
– PTSD
– OCD
– Psychosis (other than schizophrenia)
– Acute treatment of aggression and agitation
FGA – Mechanism of Action
diagram
postsynaptic d2 antagonism
Effect of Nonselective Dopamine (D2) Antagonism of FGA
at dif D paths
Dopaminergic Pathways – Effect of FGA on pathways
FGA Efficacy and activity
- limited spectrum of efficacy/ activity, only tx’s psychosis
Relative Potencies of FGA
halo= high and chlorpro=low
what other receptors afre affects by FGAs
a1, M1, H1
Adverse Effects by Receptor
Blockade at H1 due to FGA
dry mouth, drowsy
Adverse Effects by Receptor
Blockade at M1 due to FGA
Adverse Effects by Receptor
Blockade at alpha due to FGA
Adverse Effects by Receptor
Blockade
* Dopamine antagonism
– Extrapyramidal Side Effects (EPS) – “movement disorders”
» Dystonic reaction
» Pseudoparkinsonism
» Akathisia
» Tardive dyskinesia
– Hyperprolactinemia –
» galactorrhea, menstrual irregularities /
amenorrhea, gynecomastia, sexual dysfunction
Side Effect Profile - FGA: haloperidol
Side Effect Profile - FGA: Chlopromazine
which FGA is more likely to have side effect associated with H, M and a receptors?
Chlopromazine
Extrapyramidal Side Effects (EPS) of antipsychotics
- acute dystonia
- pseudoparkinsonism
- akathasia
- tarditive dyskenisia
*
Extrapyramidal Side Effects (EPS):
Acute Dystonia
acute dystonic reaction - “severe muscle spasm”:
* eye-oculogyric crisis
* neck-torticollis
* back-retrocollis
* tongue-glossospams
* pharyngeal-laryngeal dystonia
incidence acute dystonia
2-64%
acute dystonia pathophys
mbalance between DA and ACh
acute dystonia onset
usually occurs during first 5 days of treatment or after a dosage increase
acute dystonia risk factors:
high potency AP, large doses, IM administration, young males
acute dystonia tx:
– acute treatment
– chronic treatment
– acute treatment - AC agent [ex. benztropine, diphenhydramine or a benzodiazepine
– chronic treatment - decrease dose, change AP agent, AC agent
Drugs to Treat Dystonia
dental implication?
- Benztropine- IM
- Trihexyphenidyl-IM
- Diphenhydramine
Oral side effect – dry mouth
Anticholinergic agenst target M1
Pseudoparkinsonism
signs
what aspects of pseudopark may influence dentistry
excessive drooling and rigidity/trembling of head
four cardinal symptoms of pseudoparkinsonism
– motor?
– tremor?
– rigidity?
– posture?
four cardinal symptoms
– akinesia, bradykinesia or decreased motor activity
– tremor
– cogwheel rigidity
– postural abnormalities
Pseudoparkinsonism incidence
15-36%
pseudopark pathophysiology:
decrease in DA activity
pseudopark onset
1-2 weeks after AP initiation or increase in dose
pseudopark risk factors
high potency AP, increased AP doses, age >40, female
tx pseudopark
treatment: decrease dose, change AP agent, AC agents [benztropine/Trihexyphenidyl], DA agonist [amantadine]
Drugs to Treat
Pseudoparkinsonism
dental implications?
- Benztropine
- Trihexyphenidyl
Oral side effect – dry mouth
M1 antagonists
Akathisia
- extreme motor restlessness/inability to sit still
– patient can not typically control akathisia for even a short time period
akathsia incidence
incidence: 25-36%
akathasia pathophys
pathophysiology: unknown
akathasia onset
onset: 2-4 weeks
Akathisia dif to distinguish from?
difficult to distinguish from anxiety/agitation/psychosis
– akathisia made worse with increased AP doses
akathasia risk factors
high potency AP, large AP dose