Antipsychotics Flashcards
MOA of first and 2nd generation antipsychotics:
First: Block D2 Receptors
Second: Block D2 and 5HT-2A Receptors
Efficacy differences in 1st and 2nd generation antipsychotics =
They both treat positive symptoms to the same degree but atypical antipsychotics treat negative symptoms better.
Which are the low potency antipsychotics?
- Chlorpromazine
- Thioridazine
Which are the mid-potency antipsychotics?
- Loxapine
- Thiothixene
- Trifluoperazine
- Perphenazine
Which are the High Potency antipsychotics?
- Haloperidol
- Fluphenazine
- Pimozide
What differentiates a low from a high potency antipsychotic =
affinity for the D2 receptor–the lower the affinity, the lower the potency
Difference in terms of side effects between lower and higher potency antipsychotics =
Low potency antipsychotics:
- more likely cause anticholinergic & antihistaminic s/e.
- more likely to cause QTc prolongation
- more likely to cause seizures
- more likely to cause agranulocytosis
High potency antipsychotics:
- more likely to cause EPS and NMS.
- More likely to cause tardive dyskinesia
Chlorpromazine:
- Class =
- Common side effects =
- Indications =
- Class =
• Low potency typical antipsychotic
- Common side effects = • Orthostatic Hyptotension • Bluish Skin • Photosensitivity • Obstructive Jaundice
- Indications = • Intractable hiccups • Nausea • Vomiting • Antipsychotic
Thioridazine
- Class =
- Common side effects =
- Class =
• Low potency typical antipsychotic - Common side effects =
• Retinitis Pigmentosa
Loxapine
- Class =
- Common side effects =
- Metabolite acts as a…
- Class =
• Mid potency typical antipsychotic - Common side effects =
• Higher risk of seizure - Metabolite =
• Antidepressant properties
Thiothixene
- Class =
- Common side effects =
- Class =
• Mid potency typical antipsychotic - Common side effects =
• Ocular pigment changes
Trifluoperazine
- Class =
- Indications other than anti psychosis =
- Class =
• Mid potency typical antipsychotic - Indications =
• Anxiolytic
Perphenazine
- Class =
- Class =
• Mid potency typical antipsychotic
Antipsychotics with decanoate forms available =
- Fluphenazine
- Haldol
Pimozide
- Class =
- Common side effects =
- Class =
• High potency typical antipsychotic - Common side effects =
• Heart Block
• V-Tach
• Other cardiac effects
Fluphenazine
- Class =
- Class =
• High potency typical antipsychotic
Brain pathway associated with the positive symptoms of schizophrenia =
Mesolimbic Dopamine Pathway
Structures within the mesolimbic pathway =
- Nucleus accumbens
- Fornix
- Amygdala
- Hippocampus
Brain pathway associated with the negative symptoms of schizophrenia =
Mesocortical dopamine pathway
Brain pathway associated with the EPS of antipsychotics =
Nigrostriatal pathways
NMS symptoms =
“FALTERED”
- Fever (most common sx)
- Autonomic Instability
- Leukocytosis
- Tremor
- Elevated CPK
- Rigidity
- Excessive sweating (diaphoresis)
- Delirium
“Blue-gray skin discoloration” from…
Chlorpromazine
Clozapine
- Class =
- Indications =
- Side effects =
- Effect on Suicide =
Class:
- Atypical Antipsychotic
Indications:
- Treatment refractory Psychosis
- Psychosis + suicidality
Side Effects:
- Agranulocytosis
- Tachycardia
- Hypersalivation
- Anticholinergics
- Myocarditis
- Seizures
Suicide
- Only antipsychotic which reduces the risk of suicide
When to stop clozapine in the case of agranulocytosis =
When PMN count drops below 1500/µL
Risperidone
- Class =
- MOA
- Side effects =
Class:
- Atypical Antipsychotic
MOA:
- Blocks 5HT2a, alpha-1, and D2 receptors
Side Effects:
- Hyperprolactinemia
- Orthostatic hypotension
- Reflex tachycardia
- Weight GAIN
Quetiapine
- Class =
- Indications =
- Side effects =
Class:
- Atypical Antipsychotic
Indications:
- Psychosis
- Insomnia
Side Effects:
- Sedation
- Orthostatic hypotension
Olanzapine
- Class =
- Indications =
- Side effects =
Class:
- Atypical Antipsychotic
Indications:
- Psychosis
- Mood stabilization (later line)
Side Effects:
- Weight Gain
- Metabolic Syndrome
- Sedation
Ziprasidone
- Class =
- Effect on weight =
Class:
- Atypical Antipsychotic
Effect on Weight:
- Less likely to cause weight gain
Aripiprazole
- Class =
- MOA =
- Side effects =
Class:
- Atypical Antipsychotic
MOA
- Partial D2 agonism
Side Effects:
- Akathisia
- Less potential for weight gain
- Less Sedating
Paliperidone =
Metabolite of risperidone
More expensive
Also comes in a long acting form
Best drug to use in delirious, elderly patients and why:
Haloperidol.
This is the strongest antipsychotic there is, and therefore small doses can be used while avoiding the side effects of the antipsychotics, such as the orthostatics, anti-histaminergic, and anti-cholinergic side effects.
Haloperidol also has the lowest risk of falls in these patients because it has less anti-adrenergic properties.
Reason you cannot use risperidone in elderly, delirious patients =
It only comes in oral formulations–which typically doesn’t bode well in delirious patients.
How often long-acting depot form of risperidone needs to be administered =
Bi-monthly (twice per month)
Which antipsychotics will cause EPS?
All of them, at high enough doses–except for clozapine.
Antipsychotics which come in a long-acting injectable form =
Haloperidol
Risperidone
Sialorrhea =
- What causes it?
Excessive salivation / drooling
Commonly caused by clozapine
Best treatment for sialorrhea =
Clonipine
How to deal with the persistent sinus tachycardia seen in some patients on clozapine:
- Usually you can wait and it will go away on its own.
- However, if it just will not go away then you should add a ß-blocker like propanolol.
Role of antipsychotics in bipolar disorder =
- Antipsychotics are most commonly used during the first manic episode–which is much more intense than the rest of the episodes.
- They are not commonly used for maintenance therapy due to the high risk of side effects.
Which atypical antipsychotics are the least likely to cause metabolic syndrome?
Ziprasidone > Ariprazole > Risperidone > Quetiapine
Which are the atypical antipsychotics most likely to cause metabolic syndrome?
- Olanzapine
- Clozapine
Rabbit Syndrome and what causes it =
Quivering of the mouth without involvement of the tongue. This is commonly caused by high potency antipsychotics like haldol.
Signs of pseudoparkinsonism =
- Bradykinesia
- Flexed posture
- Festinating gait
- Resting tremor
