1st gen antipsychotics Flashcards
What are the High potency FGAs
HaloPeridol
FluPhenazine
TriFluPeraZine
Low potency FGAs
Thioridazine
Chlorpromazine
Difference between high and low potency
High potency:
Stronger and more specific D2 binding and blocking
Higher risk for Extrapyramidal symptoms
Higher risk for Neuroleptic Malign Syn
Higher prolactin release and antiandrenergic effects.
But, much fewer antiadrenergic, antihistamine, and antimuscarinic effects.
-Haloperidol is the only AP that has NO effect on histamine receptors at all, and only weak alpha1 blocking
Low potency:
Less EPS
More alpha1, H1, 5HT2, and M4 blocking.
What are the phenothiazine drugs
Chlorpromazine
Thioridazine
Fluphenazine
What are the butyrophenones
Haloperidol
What are the thioxanthenes
Thiothixene
Haloperidol actions
Blocks D2 and alpha1 only.
Thioridzine actions
Blocks D2, a1, 5HT2, and H1, and very strong antimuscarinic.
What are the extrpyramidal symptoms, in order of their development
Acute dystonia,
- within hours,
- especially of the eyes, also head and neck
Akathesia
- in a few days,
- restlessness, inability to remain still,
Parkinsonism
- after days to weeks
- Bradykinesia
- Cogwheel rigidity
- Masked facies
Tardive dyskinesia
- after months or years
- tremor, especially of face, tongue, mouth
- is often irreversible!
What are the other side effects of the FGAs
Antihistamine, Antimuscarinic, Anti-androgenic.
- Orthostatic hypo
- Sedation
- Antimuscarinic effects, hot, blind, red, mad, dry, full, and constipated.
Prolactin disinhibition - strongest with high potency
- galactorrhea, amenorrhea, gynecomastia, impotence
Neuroleptic Malignant Syndrome
Rhabdomyolysis
Long QT syndrome and possible Torsades.
ALL antipsychotics, 1st and 2nd gen Lower the Seizure threshold. Increase seizures.
What are the kinetics of the FGAs
They are all lipophilic and given orally
All metabolized by the liver and are increased by CYP inhibitors
They have half lives of 20-40 hours
Unique eye effect of chlorpromazine
Corneal deposits
Unique eye effect of Thioridazine
Retinal deposits.
Indications for the FGAs
Acute psychotic episodes
Controls positive symptoms of schizophrenia, bipolar disorders
Tourettes
Sometimes used in panic disorder
2nd line for tourettes after clonidine