Pharmacology: Psychotic Disorders Flashcards
Typical Antipsychotics (1st generation): MOA
Dopamine (D-2) receptor antagonist
4 most common Typical Antipsychotics to know + related potency.
- Haloperidol + Fluphenazine: High Potency
- Chlorpromazine and Thioridazine: Low Potency
Note: Fluphenazine, Chlorpromazine, and Thioridazine are in the same class. Therefore allergic reaction for one of them will indicate an antipsychotic from a different class like haloperidol.
Difference between high and low potency (typical antipsychotics)
- Low Potency drugs are more likely to have additional effects at histamine, ACh, and adrenergic receptors.
- High Potency drugs are more selective for D2 receptors
Atypical Antipsychotics (2nd generation): Know suffix endings.
“zole”, “azine” or “ine,” “done”
Ex) aripiprazole, cariprazine, risperidone.
Atypical Antipsychotics (2nd generation): MOA
D2 antagonist and 5-HT(2A) antagonist.
- Blockade of serotonin prevents dopamine inhibition => leads to dopamine functioning “normally”.
Typical vs Atypical Antipsychotics: Adverse Effects
Both are effective towards positive symptoms but atypicals theoretically have less exacerbation of negative symptoms.
Adverse Effect: Early Onset Extrapyramidal Symptoms:
Associated Antipsychotics, Sx, and Treatment
More common in high potency typicals (haloperidol/fluphenazine)
- Symptoms: Dystonia, Pseudoparkinsonism, and Akathisia: TX with ANTICHOLINERGICS. (specifically propranolol for akathisia because it crosses the BBB)
Adverse Effect: Hyperprolactinemia:
Associated Antipsychotics, Sx, and Treatment
More common in high potency typicals (haloperidol/fluphenazine)
- Sx of Amenorrhea, galactorrhea, gynecomastia.
Adverse Effect: Neuroleptic Malignant Syndrome:
Associated Antipsychotics, Sx, and Treatment method
More common with typicals in general but can be seen with atypicals.
- Sx include confusion, hyperthermia, rigidity. NEED TO STOP DRUG.
Patient wakes up with confusion, blurred vision, dry eyes and mouth, urinary retention. What kind of drugs is she taking?
Anticholinergic Effects
-antipsychotics (doesn’t specify in lecture but in First Aid, refers to typicals)
Patient has weight gain and metabolic syndrome. What drug is she taking.
atypical antipsychotics
Patient presents in the ER with Torsades de Pointes. What drug is she taking?
Heart related effects: QT prolongation
- Usually haloperidol or Ziprasidone
Patient develops cataracts. What drug is she taking
Phenothiazines (typical) and Quetipaine (atypical)
Patient wakes up from sleep due to really wet pillow. What drug is she taking?
Specifically clozapine!
What are the black box warnings for all antipsyhotics
Increase mortality in elderly patients with dementia related psychosis.
Black Box warning specifically for Clozapine
Arganulocytosis, seizures, myocarditis, and other cardiac and respiratory effects.
What are some warnings about antipsychotics you give to pregnant patients or patients that just gave birth?
Pregnancy category C and breast feeding should be avoided.
Drug Interactions of Antipsychotics
Cytochrome P450!
- CYP 3A4 and 2D6 are most common.
- Smoking induces CYP 1A2
Patient returns for the 10th time this past year complaining of minimal improvement on his schizophrenia. Has tried 1st and 2nd generation atypicals and they all suck. What do you prescribe him?
Clozapine: Preferred in TREATMENT REFRACTORY PATIENTS because of significant side effects of (black box warning) Arganulocytosis, seizures, myocarditis, and other cardiac and respiratory effects.
Treatment Algorithm for Schizophrenia
First: 2nd generation (atypical) antipsychotic EXCEPT clozapine
Second: Different atypical antipsychotic OR 1st generation (typical) antipsychotic
Third: Try a trial of Clozapine
