Term
What does the mesolimbic pathway control?
What happens when there is an INCREASE of dopamine in this pathway? |
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Definition
Related to behaviour
Psycosis |
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Term
What does the Nigrostriatal pathway control?
What happens if there is a DECREASE of dopamine in this pathway |
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Definition
Coordination of voluntary movement
Movement disorders |
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Term
What does the tuberoinfundibular pathway control?
What happens when there is a DECREASE of Dopamine in this pathway? |
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Definition
Inhibits Prolactin secretion
Hyperprolactenemia |
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Term
| Name the Dopamine receptors that are implicated in schizophrenia and what they are coupled to? |
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Definition
| D2 - negatively coupled to adenylyl cyclase |
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Term
| What are the proposed pathways in schizophrenia? |
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Definition
Dopamine hypothesis:
•Proposes that the disorder is caused by relative excess of dopamine in the mesolimbic-mesocortical pathway
•New hypothesis suggests that serotonin is also involved in the pathophysiology (5-HT2)
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Term
How is schizophrenia treated in general?
What are the general ADRs? |
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Definition
Blocking D2 receptors
Hyperprolactinemia (blocking tuberoinfunfibular pathway)
Movement Disorders (blocking the nigrostriatal pathway) |
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Term
| What are the Positive symptoms of Schizophrenia? |
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Definition
hallucination, delusions, thought dysfunction - clearly related to increased dopamine levels in the mesolimbic pathway
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Term
| What are the Negative symptoms of Schizophrenia? |
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Definition
deficiencies in emotional responsiveness, spontaneous speech and volition.
Negative symptoms are shown in flattening of affect, poverty of speech, and drive, loss of feeling, social withdrawal and decreased spontaneous movement
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Term
| Name the Traditional Antipsycotics |
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Definition
Phenothiazines
•Chlorpromazine
•Thioridazine
•Trifluoperazine
•Fluphenazine
Nonphenothiazines
•Loxapine
•Haloperidol
•Molindone
Thiothixene |
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Term
| What symptoms of schizophrenia do the traditional antipsychotics/neuroleptics help treat? |
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Definition
| Positive symptoms - hallucinations, delusions, thought dysfunctions |
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Term
| What are the other uses of traditional antipsychotics/ Neuroleptics? |
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Definition
•Except thioridazine all have very good antiemetic effect
•Sedatives
•Antipruritic action (histamine receptor blockade)
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Term
| All Neuroleptics/Traditional antipsychotics have a good antiemetic effect EXCEPT? |
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Definition
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Term
How is Touretts treated?
What is its method of action? |
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Definition
haloperidol, pimozide
Traditional antipsychotics/ Neuroleptics |
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Term
What is Coprolalia?
WHat is the DOC for this? |
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Definition
Use of obscene language in public. seen with touretts
DOC: haloperidol |
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Term
| What are the ADR's related to neuroleptics? |
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Definition
EPS - involuntary movements - VERY EARLY INTO THEAPY (due to lack of dopamine
Tardive dyskinesia (abnormal movements)- FROM 6 months onwards
M1 blockade
H1 blockade
A1 blockade
QT prolongation |
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Term
| Which neuroleptics have the specific ADR of QT prolongation? |
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Definition
Thioridazine
Ziprasidone
Pimozide |
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Term
What are the clinical features of EPS?
Why does this occur?
What is given to treat it? |
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Definition
Happens INITIALLY when therapy starts
Bradykinesia, Tremor & Muscle rigidity
Due to D2 blockade
Anticholinergics are given i.e Benztropine, Diphenhydramine or Trihexyphenydyl |
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Term
What are the clinical features of Tardive dyskinesia?
Why?
What is given to treat it? |
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Definition
•Choreoathetoid movements - Especially of muscles of lips, and buccal cavity
Occurs 6 months following therapy
D2 receptor blockade for a very long time - D2 receptors unregulated due to chronic antagonist - excessive dopaminergic activity
Temporary fix - higher dose of neuroleptic
Switch the patient on to the newer drugs
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Term
What is Neuroleptic malignant syndrome (NMS)?
How is it treated? |
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Definition
Same as malignant hyperthermia - fever, muscle rigidity (increase in CK levels), altered mental status
Dantroline |
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Term
| What are the Endocrine effects of neuroleptics? |
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Definition
Hyperprolactinemia
Gynaecomastia - in males
Galactorrhea & Infertility (amenorrhea) - in females |
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Term
Name the Atypical/ Newer antipsychotics?
What is the MOA
What is the advantage of using these drugs over the typical drugs? |
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Definition
•Clozapine
•Risperidone
•Olanzepine
•Ziprasidone
MOA:blockade of Dopamine D2 & Serotonin 5-HT2 receptors
Faster dissociation from the Dopamine receptors, thus less ADR's related to dopamine blockade
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Term
| EPS is seen more commonly which which typical antipsychotic/ neuroleptic? |
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Definition
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Term
| What are the ADR's associated with Clozapine? |
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Definition
Weight gain
Impared glucose tolerance
Agranulocytosis
Provoked seizures
Postural hypotension |
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Term
| What is a specific ADR of ALL D2 blockers? |
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Definition
Decrease seizure threshold!!
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Term
| What is impaired glucose tolerance? |
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Definition
Impaired glucose tolerance (IGT) is a pre-diabetic state of dysglycemia, that is associated with insulin resistance and increased risk of cardiovascular pathology. IGT may precede type 2 diabetes mellitus by many years. IGT is also a risk factor for mortality.
Symptoms may include excessive thirst and urination |
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