Antipsychotic Drugs

Question 1

Antipsychotic drugs are also called

Answer 1

Antischizophrenic drugs
Major tranquillisers
Neuroleptics

Question 2

What are the features of antipsychotic drugs

Answer 2

Not curative.
Requires several weeks to control symptoms
90%of patients require a maintenance dose
There’s usually a relapse
70%of patients experience a relapse when the drug is stopped
There’s a level of tolerance and physical dependence

Question 3

What is psychosis

Answer 3

Psychosis is simply a disconnection from reality

Question 4

What is schizophrenia

Answer 4

A mental disorder characterized by psychosis

Question 5

The prevalence of schizophrenia is equal in males and females T/F

Answer 5

True

Question 6

The prognosis of schizophrenia is poor T/F

Answer 6

True

Question 7

What receptor is mainly responsible for the action of antipsychotic drugs

Answer 7

D2 - inhibitory

Question 8

The dopamine receptor selective for sulpiride is

Answer 8

D2 like Receptor

Question 9

D1B receptor is ……..

Answer 9

D5 receptor

Question 10

D2 receptors inhibit ……..

Answer 10

cAMP and
GIRK

Question 11

GIRK keeps the neurons in the hyperpolarized state, its inhibition by D2-like receptors results in …….

Answer 11

It allows the neurons to remain depolarized making them unable to initiate another signal

Question 12

D1 receptor is selective for ……

Answer 12

SCH2339

Question 13

The dopaminergic Pathways include

Answer 13

Mesocortical pathway
Mesolimbic
Nigrostriatal
Tuberoinfudibular pathway

Question 14

A loss of integrity of the dopaminergic Pathways manifests as …… in the respective pathways

Answer 14

Mesolimbic - positive symptoms
Mesocortical- negative symptoms
Nigrostriatal pathway- extrapyramidal symptoms
Tuberoinfudibular - hyperprolactinaemia

Question 15

The 5 functions of dopamine and the system or Pathways involved

Answer 15

Motivation, reward, cognition-mesolimbic
Hyperfunction in schizophrenia

Mesocortical- emotions and cognition hypofunction I schizophrenia

Motor control- nigrostriatal pathway
Extrapyramidal side effects
Endocrine control -Tuberoinfidibular
Hyperprolactinemiain treatment

Emetic effects CTZ in medulla

Question 16

The major neurotransmitters involved in the pathogenesis of schizophrenia is

Answer 16

Dopamine
Glutamate
Serotonin

Question 17

Briefly describe the effects of drugs on schizophrenia

Answer 17

Drugs like amphetamine. Cocaine and levodopa which results in Increased release of dopamine or in the quantity aggravates the positive sympathetic associated with schizophrenia
D2 receptor agonist like Apomorphine and bromocriptine also produce behavioural abnormalities in animals

D2 receptor antagonist are then effective in controlling the positive features of schizophrenia

Some evidence show that there is variation in D4 receptor which might make it a potent receptor for antipsychotic drugs

Question 18

Role of glutamate in schizophrenia

Answer 18

Reduced glutamate conc and densities have been reported in postmortem brains of schizophrenics

Glutamate NMDA receptor antagonists like ketamine and phencyclidine have been reported to produce thought disorders, Hallucinations in humans

Question 19

What is the role of serotonin in schizophrenia

Answer 19

Serotonin has a modulator effect on dopamine i.e it sort of counter the effect of dopamine..

Drugs like LSD with mixed agonist and antagonist effects have been found to produce behavioral abnormalities

Some antipsychotic drugs also work on serotonin receptors (antagonists)

Question 20

The MOA of typical antipsychotics include

Answer 20

D2 antagonism
Some work on D4 receptor toi

Serotonin blockade ( may improve negative symptom)
Histamine blockade( drowsiness)
Alpha adrenoceptor blockade( postural hypertension)

Question 21

Typical antipsychotics have a limited spectrum of efficacy, explain

Answer 21

They target the control of positive symptoms

Question 22

The atypical antipsychotics have

Answer 22

Significantly reduced side effect
Improved efficacy profile