Antipsychotics Flashcards
Another name for antipsychotic drugs
Neuroleptics
Another name for typical antipsychotics
Conventional antipsychotics
What receptors do typical antipsychotics block?
Dopamine type 2 (D2) receptors
Blocking the D2 receptor decreases neurotransmission in what pathway? What is the result?
Mesolimbic pathway - reduces positive symptoms like hallucinations
Are antipsychotic meds specific in terms of receptors blocked?
No - all receptors are blocked in multiple pathways, so lots of side FX
What pathway is the therapeutic target of D2?
Mesolimbic
Blocking the mesolimbic pathway additionally blocks what functions of the pathway? What side FX does this result in?
Reward and pleasure - leads to apathy, anhedonia, amotivation, social withdrawal, known as secondary negativism b/c it’s in addition to negative symptoms
Dopamine blockade can worsen the deficit in what pathway, leading to worsening of cognitive and emotional symptoms? It may already be deficient in what disease?
Mesocortical pathway
Schizophrenia
Potent D2 blockade in the nigrostriatal tract results in what short-term extrapyramidal side effects (EPS):
- Parkinsonian symptoms
- Dystonic symptoms
- Akathesia
Dopamine normally suppresses what neurotransmitter activity in nigrostriatal pathway
Acetylcholine
What medications are used to treat extrapyramidal side effects (EPS)
Anticholinergics - diphenhydramine or benztropine
Long-term D2 blockade in nigrostriatal pathway results in what movement disorder
Tardive dyskinesia (TD) - involuntary tongue and facial movements
Dopamine blockade in tuberoinfundibular tract leads to what side effects as a result of increased plasma prolactin
Galactorrhea, amenorrhea, infertility, bone loss
Name the blockade that causes the following side FX:
Dry mouth, blurred vision, constipation, cognitive blunting
Muscarinic anticholinergic blockade
Name the blockade that causes the following side FX:
Weight gain and drowsiness
Histamine blockade
Name the blockade that causes the following side FX:
Orthostatic hypotension
a-1 adrenergic blockade
What syndrome is a rxn to antipsychotics and involves:
High fever, muscle rigidity, confusion, autonomic instability, high serum creatinine phosphokinase, high liver enzymes
Neuroleptic Malignant Syndrome (NMS)
Haloperidol (Haldol)
Side FX?
High potency typical anti-psychotic, potent D2 antagonism
-EPS, TD, NMS
Chlorpromazine (Thorazine)
Side FX?
Low potency typical anti-psychotic, less potent D2 antagonism
- Anticholinergic side FX
Mechanism differences that make an antipsychotic atypical
What side FX do these drugs decrease?
1) Shorter binding time at D2 receptors
2) 5HT2A antagonism
EPS and hyperprolactinemia, as well as tardive dyskinesia (b/c shorter D2 binding periods mean less striatum sensitization), decreases negative symptoms
What receptor does serotonin bind on dopamine neurons? What action does this have?
5HT2A - inhibits dopamine release
Clozapine (Clozaril)
Atypical antipsychotic
Reduces risk of suicide, decreases violence and aggression
Side FX: AGRANULOCYTOSIS (test question), sedation, seizures
causes few EPS, no TD, no prolactin elevation
Olanzapine (Zyprexa)
Atypical antipsychotic
No EPS symptoms, very sedating,
Risperidone (Risperdal)
Atypical antipsychotic at lower doses
At high doses, acts more like a typical antipsychotic, which leads to EPS and increases prolactin
Approved for pediatric use
Paliperidone (Invega)
Atypical antipsychotic
Next generation of Risperidone, sustained release, more easily dosed, less EPS FX
Increases QTc interval
Qeutiapine (Seroquel)
Atypical anti-psychotic
Used preferentially in Parkinson’s patients
virtually NO EPS, no prolactin elev, may have enhanced NE activity
Ziprasidone (Geodon)
Atypical antipsychotic that SIGNIFICANTLY prolongs QTc interval
Low symptoms of EPS, low prolactin elev, less propensity for weight gain
Aripiprazole (Abilify)
Atypical antipsychotic
Role for augmentation in depression, not as sedating, can cause agitation or akathesia, lower CM risk
Drawbacks of atypical anti-psychotics?
- Increase risk factors for cardiac/metabolic disease
- Weight gain, obesity
- Diabetes
- Premature death
Successful treatment of though disorders involves optimizing ______ function (what neurotransmitter?)
Dopamine
Weight gain as a result of atypical anti-psychotics is mediated through what mechanisms
Histamine blockade and through actions of serotonin systems (5HT2C)
Most risk to least risk for weight gain and CM risk amongst atypical anti-psychotics?
COQR/PZA Clozaril Olanzapine Quetiapine Risperidone/Paliperidone Zipasidone Aripiprazole
