Antipsychotic Drugs Or Neuroleptics

Front 1

Define psychosis

Back 1

Psychosis (e.g., Schizophrenia) is a ubiquitous chronic neuropsychiatric disease characterized by severe behavioural perturbations, with distorted or non-existent sense of reality and perception

Front 2

Symptoms of psychosis

Back 2

Grouped into the positive (delirium, hallucination), negative (depression) and cognitive (leaning and memory impairments) symptoms

Front 3

Pathogenesis of Schizophrenia

Back 3

Genetic factors:

Neuregulin 1 (NRG1) Disrupted-in-schizophrenia 1 (DISC1)

Catechol-o methyltransferase gene (COMT)

Dystrobrevin binding protein 1 or dysbindin (DTNBP1)

α7-nicotinic receptor polymorphisms

Front 4

Psychosis is a neurodevelopmental disorder T/F?

Back 4

T

Front 5

Aetiology of Schizophrenia: Neurochemical hypotheses

Back 5

Dopamine hypothesis

Other hypotheses:  Glutamate hypothesis  Serotonin hypothesis  GABAergic hypothesis  Microglia hypothesis  Neurotrophic hypothesis

Front 6

Types of dopamine receptors

Back 6

The 5 types of dopamine receptors consist of two separate families: the D1-like (D1 and D5)

and D2-like (D2, D3 and D4) receptor groups

Front 7

D1 family

Back 7

In the D1-like family, the D1 receptor is located mainly in the putamen, nucleus accumbens, and olfactory tubercle while D5 is found in the hippocampus and hypothalamus. They both act by increasing cAMP by Gs-coupled activation of adenylyl cyclase

Front 8

D2 of D2 family

Back 8

In the D2,-like family, the D2 receptor decreases cAMP (by Gi-coupled inhibition of adenylyl cyclase), and inhibits calcium channels but opens potassium channels. It is found both pre- and postsynaptically on neurons in the caudate-putamen, nucleus accumbens, and olfactory tubercle. 

Front 9

D3 and 4 of D2 family

Back 9

The D3 receptor is thought to decrease cAMP and is located in the frontal cortex, medulla, and midbrain. D4 receptors also decrease cAMP

Front 10

Dopamine hypothesis is the oldest and most fully developed of hypothesis because:

Back 10

1) Many antipsychotic drugs strongly block postsynaptic D2 receptors in the CNS, especially in the mesolimbic-frontal system

2) Drugs that increase dopaminergic activity, such as levodopa, amphetamines , and apomorphine, either aggravate schizophrenia or produce psychosis

Front 11

Cont

Back 11

3) Dopamine receptor density has been found postmortem to be increased in the brains of schizophrenics who have not been treated with antipsychotic drugs;  4) Positron emission tomography (PET) has shown increased dopamine receptor density in both treated and untreated schizophrenics when compared with such scans of nonschizophrenic persons; and

Front 12

Cont

Back 12

5) Successful treatment of schizophrenic patients has been reported to change the amount of homovanillic acid (HVA), a metabolite of dopamine, in the cerebrospinal fluid, plasma, and urine.

Front 13

Classify Antipsychotic drugs first generation

Back 13

First generation (Typical) antipsychotic drugs

(i) Phenothiazines: Aliphatic side chain, Triflupromazine Piperidine side chain, Piperazine side chain

(ii) Butyrophenones: Haloperidol, Trifluperidol, Penfluridol, droperidol (iii) Thioxanthenes: Chlorprothiexe, thiothixene, Flupenthixol

(iv) Other heterocyclics: Pimozide, Loxapine

Front 14

Classify Antipsychotic drugs

Back 14

First and second generation

Front 15

Classify Antipsychotic drugs 2nd generation

Back 15

Second generation (Atypical) antipsychotic: Clozapine, Risperidone, Olanzepine, Quetiapine, Aripriprazole, Ziprasidone, Amisulpride, Zotepine

Front 16

Typical and atypical because

Back 16

because they bind to D2 receptor

Because they bind to other receptors respectively