Exam #02 (Antipsychotics) Flashcards
Why is schizophrenia thought to be a paradoxical disease?
B/c there are positive and negative symptoms arising from excess DA and not enough DA, respectively
Positive symptoms of schizophrenia arise from excess DA in what tract of the brain?
mesolimbic tract
Negative symptoms of schizophrenia arise from reduced DA in what tract of the brain?
mesocortical tract
List the (3) positive symptoms of schizophrenia.
- Hallucinations
- Delusions
- Disorganized thinking
List the (3) negative symptoms of schizophrenia.
- Blunted affect
- Emotional withdrawal
- Poor rapport
Cognitive symptoms may result from INCREASED/DECREASED dopamine in the medial prefrontal cortex?
DECREASED
What (4) NT are implicated in schizophrenia?
- DA
- Glutamate
- Serotonin
- GABA
What is the difference between typical antipsychotic and atypical antipsychotic drugs? Indicate MOA and SE profile
Typical Antipsychotics
MOA: DA antagonists (D2)
SE: primary side effects are extrapyramidal side effects (EPS) which are movement abnormalities
Atypical antipsychotics
MOA: primarily 5-HT2A antagonism but can also have some DA antagonism
SE: reduced or no EPS (b/c less D2 antagonism) but significant increase in other side effects
True or False - most antipsychotic drugs today treat positive symptoms of schizophrenia?
True
What 2 drugs led to the DA hypothesis of schizophrenia? What is the DA hypothesis?
- Chlorpromazine - DA antagonist
- Reserpine - depletes synaptic DA
Modulating DA may Tx schizophrenia
What would a “perfect” DA-based antipsychotic look like (indicate MOA in specific areas of brain)?
- Drug would act as a DA antagonist in mesolimbic neurons where excess DA is
AND
- Drug would act as a DA agonist in the mesocortical, limbic, and prefrontal cortex neurons where reduced DA is
AND
- Drug would have no effect on nigrostriatal neurons
What is the key structural feature regarding the SAR of Phenothiazines?
The affinity to D2 receptor is determined by how easily the basic amine can fold over and lie over the ring containing the substituent. This is the conformation required to make it a D2 antagonist
What helps keep the Nitrogen up over the aromatic ring in a phenothiazine drug?
the electron-withdrawing group
When the basic amine folds up over the aromatic ring, the lone pair of electrons from the basic amine dissociates and that electron density is pulled away from the ring by the electron withdrawing group stabilizing the basic amine above the ring and maintaining D2 antagonist activity
True or False - the basic amine of phenothiazines has significant structural tolerance and can be changed to modify ADME properties?
True
Identify what antipsychotic group the following drug is from:
Triflupromazine (Vesprin)
Phenothiazine
Identify what antipsychotic group the following drug is from:
Thioridazine (Mellaril)
Phenothiazine
Identify what antipsychotic group the following drug is from:
Mesorindazine (Serentil)
Phenothiazine
Identify what antipsychotic group the following drug is from:
Prochlorperazine (Compazine)
Phenothiazine