CNS Drugs Flashcards
What is schizophrenia characterized by?
Psychosis with a marked thinking disturbance
How common is schizo?
Very. Almost 1%
What are the two broad risk factors mentioned?
Neuregulin 1 family, and viral infections in vitro
Explain the dopamine theory
Most antipsychotics block postsynaptic D2 receptors
Increasing dopamine has marked effects on schizo pts
HVA more available after successful treatment
Explain the serotonin hypothesis
Basically drugs that affect serotonin can treat schizo. Drugs like hallucinagens create similar effects to schizo???
Serotonin is related to the regulation of DA
Explain the glutamate hypothesis.
NMDA receptor antagonists exacerbate schizo pyschosis
Serotonin antagonists are more potent than D2 antagonists in blocking the effects of NMDA antagonists
Ampakines are effective in correcting animal schizo behaviors
What are the three classes of typical antipsychotics?
Phenothiazine, thioxanthene, and butyrophenone
What is the apophatic phenothiazine?
Chlorpromazine
What is the piperidine phenothiazines?
Thioridazine and mesoridazine
What are the pros and cons to using piperidine phenothiazines as opposed to aliphatics?
Much less EPS and sedative, but sever weight gain
What are the piperazine phenothiazines?
Fluphenazine, perphenazine
What are the the pros and cons to piperazine phenothiazines?
Potent and selective (LEAST SEDATIVE/HYPOTENSIVE, BUT SEVERE EPS)
What are the aliphatic and piperzine thioxanthenes?
Chlorprothixene
Thiothixene
What is the one butyrophenone?
Haldol
What are the pros/cons of haldol?
More potent with fewer autonomic effects, but more EPS effects
What is the MOA of antisphycotics?
Suppression of conditioned responses, increased DA activity in mesolimbic/mesocortical areas, blockage of DA and serotonin receptors
What receptor category is Dopamine receptors?
GCPR’s
Which D receptor in excitatory and which is inhibitory?
D1-exitatory
D2-Inhibitory
What are the side effects of antisphycotics?
Depression, sedation (aliphatics most potent)
Decrease of seizure threshold
Antiemetic
EPS symptoms
Tarditive dyskinesia- Late appearing neurological syndrome
What are extrapyramidal symptoms?
Parkinsons syndrome-drug induced
Akathisia- Discomfort, leading to constant movement
Acute dystonia, torticollis (turning head side to side)
Catatonia, hyperthermia
Neuroleptic malignant syndrome
What is tardative dyskinesia?
Supersensitity of the DA receptor in the basal ganglia causing a relative cholinergic deficiency
Uncontrolled movements
How do you decrease the side effects of TD?
Alter drugs, either decrease of change all together
What are the peripheral side effects of antipsychotics?
Hyperprolactinemia, amenorrhea Altered body temp, poikilothermia Alpha-adrenergic blockade-hypotension Anticholinergic actions Hypersensitivity reactions Weight gain
What is important to remember when it comes to the metabolism of typical antipsychotics?
Significant first-pass metabolism
What are things to avoid with typical antipsychotics?
CNS depressents
Dopamine agonists- LEVODOPA
CYP450 inhibitors- KETOCONAZOLE
With digitalis: ZIPRASIDONE
Do typical antipsychotics have a high or low therapeutic index? Meaning what?
Very high, so its very safe
What are the six new antipsychotic drugs?
Clozapine, olanzapine, loxapine, risperidone, quetapine, arpiprazole
What is the most important side effect to remember for clozapine?
Fatal agranulocytosis, so monitor WBC weekly for first 6 months, then every 4 weeks after
Which new antipsychotic drug is the most tolerable?
Olanzapine
Can you give olanzapine to old people with dementia?
No
How does risperidone relate to clozapine?
Similar, but more potent DA antagonism than clozapine
How does quetiapine relate to risperidone?
Similar to risperidone, weak anticholinergic effects
What new antipsychotic is the most prescribed by total dollar?
Aripiprazole
What are three key points to remember when prescribing antipsychotics?
Adverse effects
Efficacy
Pt past response
