CNS Antiphyscotic Drugs

Question 1

Biological basis of psychosis

Answer 1

Increase = dopamine concentration , receptor , activity , production
Decrease = dopamine metabolism

Question 2

Antipyschotic drugs are

Answer 2

Typical (older drugs)
Atypical ( newer drugs )

Question 3

Typical AP drugs are

Answer 3

A] Phenothiazine derivatives = Chlorpromazine Prochlorperazine Trifluperazine Fluphenazine Perphenazine Thioridazone

B] Thioxanthene derivatives = Thiothixene

C] Butyrophenone derivatives = Haloperidol

D] Others = Pimozide Molindone

Question 4

Atypical AP drugs are

Answer 4

Clozapine
Olanzepine
Risperidone
Iloperidon
Loxapine
Quetiapine

Question 5

M/A of antipsychotic drugs

Answer 5

It acts by blocking of dopaminergic pathway as following `:
1) MESOLIMBIC MESOCORTICAL pathway blocks : antipsychotic action and sedative action
2) NIGROSTRIATAL pathway blocks : Extrapyramidal pathway syndrome = Parkinson’s syndrome , Akathisia , Tardive dyskinesia , Acute dystonic reaction
3) TUBEROINFUNDIBULAR pathway blocks : Women = Ammenorrhoea , Galactorrhoea , Pseudopregnancy , decreased libido
Male = Gynaecomastia , decreased libido
4) MEDULLARY PERIVENTRICULAR pathway blocks = Weight gain
5) INCERTOHYPOTHALAMIC pathway blocks = Hypothermia

Other effects are : Histamine blocking action = Sedation , Anti allergic action

Question 6

Non psychotic uses of cholrpromazine

Answer 6

Sedation
Headache
Anti emetic
Pruiritus \ Itching
Hiccup

Question 7

A/E of AP drugs

Answer 7

EPS
Sedation
Women = ammennorhea galactorrhoea pseudo pregnancy decreased libido
Men = gynecomastia , decreased libido
Weight gain

Question 8

50 yrs patient developed tremor and rigidity after a metochlorpromide , cause and treatment

Answer 8

It is a metochlorpromide induced Parkinson Syndrome
Explanation = it is a lipid soluble drug so crosses BB B and causes EPS
Treatment Immediate stop the drug
Administration of antimuscarinic drug ( procyclidine )

Question 9

A patient was diagnosed with mental illness , doc prescribed clozapine and procylidine ? Why used

Answer 9

Action of clozapine = clozapine blocks D2 and D4 receptor —> decrease dopaminergic action —-> anti psychotic action

Action of procyclidine = procyclidine minimises the muscarinic effects and reduce adverse effects of clozapine

Question 10

Compare haloperidol / chlorpromazine with clozapine / olanzepine

Answer 10

Haloperidol/ Chlorpromazine = Typical Anti psychotic drug , low potent , HIgh EPS , More anti emetic Effects , More hypotensive action , increased prolactin level , more sedative effect

Clozapine / olanzepine = Atypical Anti psychotic drug , Highly potent , Less EPS , Less anti emetic effects , less hypotensive action , no effect on prolactin level , less sedative effect