Antipsychotic drugs, also known as neuroleptics, are used to treat psychotic disorders like schizophrenia. There are two main types - first generation "typical" antipsychotics that are associated with more extrapyramidal side effects, and second generation "atypical" antipsychotics that have fewer of these motor side effects. Antipsychotics work by blocking dopamine receptors in the brain, particularly in the mesolimbic pathway. They can have various adverse effects involving the cardiovascular, nervous, endocrine and other body systems. Proper management of these drugs requires monitoring for potential toxic reactions and drug interactions.

1. ANTIPSYCHOTICS
OR
NEUROLEPTICS

2. • from the Greek "psyche", for mind/soul,
and "-osis", for abnormal condition or
derangement)
• Psychotic illnesses are characterized by
disordered thought processes
WHAT IS PSYCHOSIS

3. • The psychoses are among the most
severe psychiatric disorders
• Serious inability to think
• Symptoms of false beliefs (delusions)
• Abnormal sensations (hallucinations)
• Representative syndromes in this
category include schizophrenia brief
psychoses, and delusional disorders.

4. • Psychosis results from an overactivity of
dopamine function in the brain,
particularly in the mesolimbic pathway
• Substance induced
Pathophysiology

5. • The purpose of the brain is to collect
information from the body (pain, hunger,
etc.), and from the outside world, interpret it
to a coherent world view, and produce a
meaningful response. The information from
the senses enter the brain in the primary
sensory areas. They process the information
and send it to the secondary areas where
the information is interpreted. Spontaneous
activity in the primary sensory areas may
produce hallucinations which are
misinterpreted by the secondary areas as
information from the real world.

6. • Tertiary brain cortex collects the
interpretations from the secondary
cortexes and creates a coherent world
view of it. A study investigating structural
changes in the brains of people with
psychosis showed there was significant
grey matter reduction in the right medial
temporal, lateral temporal, and inferior
frontal gyrus, and in the cingulate cortex
bilaterally of people before and after
they became psychotic

7. • sensory deprivation have shown that the
brain is dependent on signals from the
outer world to function properly. If the
spontaneous activity in the brain is not
counterbalanced with information from
the senses, loss from reality and psychosis
may occur after some hours

9. • CLASSIFICATION OF ANTIPSYCHOTIC
DRUGS
CLASSIFICATION

10. • dopamine receptor antagonists
• 5-hydroxytryptamine (5-HT) receptors
antagonists
PHARMACOLOGICALLY, THEY ARE
CHARACTERISED AS

11. • Antischizophrenic drugs or major
tranquillisers-conventionally refers to
those used to treat schizophrenia, one of
the most common and debilitating forms
of mental illness.
ANTISCHIZOPHRENIC:

12. • Classification of antipsychotic drugs main
categories are:
– First-generation ('typical') antipsychotics (e.G.
Chlorpromazine, haloperidol , fluphenazine,
flupenthixol, clopenthixol)
– Second-generation ('atypical') antipsychotics
(e.G. Clozapine , risperidone , sertindole,
quetiapine, amisulpride, aripiprazole ,
zotepine).

13. • Distinction between typical and atypical
groups is not clearly defined but rests on:
– Receptor profile
– Incidence of extrapyramidal side effects (less
in atypical group)
– Efficacy (specifically of clozapine ) in
'treatment-resistant' group of patients
– Efficacy against negative symptoms.

14. • Delusions
• Hallucinations- Auditory, Visual, Olfactory,
and Tactile
• Losing Sense of Reality
• Disorganization of Thought
• Thought Blocking
SYMPTOMS :

15. • Bipolar Disorder
• Shizophrenic disorders
• Depression
• Personality Disorders
DISORDERS WITH PSYCHOSIS:

16. Two main different types:
• Bipolar I
• Manic around 1 week
• Depressive around 2 weeks
• Bipolar II
• Depressive
• Hypomanic
Treatments:
Mood Stabilizers:
- Lithium
Antipsychotics
BIPOLAR DISORDER

17. Symptoms:
• Delusions
• Hallucinations
• Disorganized speech and behavior
• Negative Symptoms
• Blunted affect (lack of emotional reactivity)
• Alogia (poverty of speech)
• Avolition ( lack of drive, or motivation to
pursue meaningful goals)

18. • Treatment:
– Mood Stabilizers
– Antipsychotics

20. • Phenothiazine antipsychotic drugs
TRICYCLIC ANTIPSYCHOTIC
AGENTS

21. • Prominent sedative effect
• Adverse autonomic and neurologic
effects, severe anxiety and restlessness
(akathisia)
• The risk of developing advers
extrapyramidal effects, including tardive
dyskinesia
PHARMACOLOGICAL PROPERTIES

22. • Auditory processing and attention, spatial
organization, verbal learning, verbal
memory, and executive functions, are
impaired in schizophrenia patients. Potent
d2-antagonist neuroleptics have very limited
beneficial effects on such functions. Some
atypical antipsychotic agents with mixed
D2/5-HT2A activity (including clozapine,
quetiapine, olanzapine, and risperidone), as
well as the D2 partial agonist aripiprazole,
seem to improve cognitive functioning in
psychotic patients.
1-EFFECTS ON COGNITIVE FUNCTION

23. • Antipsychotic drugs have inconsistent
effects on sleep patterns but tend to
normalize sleep disturbances
characteristic of many psychoses and
mania.
2-EFFECTS ON SLEEP

24. • Actions of antipsychotic agents are
based on their ability to antagonize the
actions of DA as a neurotransmitter in the
basal ganglia and limbic portions of the
forebrain.
3-EFFECTS ON SPECIFIC AREAS OF
THE NERVOUS SYSTEM

25. • Antipsychotic drugs interact with
dopaminergic projections to the
prefrontal and deep-temporal (limbic)
regions of the cerebral cortex, with
relative sparing of these areas from
adaptive changes in DA metabolism
4-CEREBRAL CORTEX

26. • Many neuroleptic drugs can lower the
seizure threshold and induce discharges in
the electroencephalogram (EEG) that are
associated with epileptic seizure disorders.
Clozapine, olanzapine, and aliphatic
phenothiazines with low potency (e.g.,
chlorpromazine) seem particularly able to do
this.
• while the more potent piperazine
phenothiazines and thioxanthenes
fluphenazine and thiothixene), risperidone,
and quetiapine are much less likely to have
this effect.
5-SEIZURE THRESHOLD

27. • Antagonism of DA-mediated synaptic
neurotransmission is an important action of
many antipsychotics,this prompted the
proposal that many adverse extrapyramidal
neurological and neuroendocrinological
effects of the neuroleptics are mediated by
antidopaminergic effects in the basal
ganglia and hypothalamic systems, whereas
the antipsychotic effects of neuroleptics are
mediated by modification of dopaminergic
neurotransmission in the limbic and
mesocortical systems

28. • Many antipsychotic drugs also block the
effects of agonists on DA-sensitive adenylyl
cyclase associated with D1/D5-receptors in
forebrain tissue
• Atypical antipsychotic drugs such as
clozapine and quetiapine are characterized
by low affinity or weak actions in such tests.
Initially, the standard antipsychotics increase
firing and metabolic activity in dopaminergic
neurons. These responses eventually are
replaced by diminished presynaptic activity
(“depolarization inactivation”) with reduced
firing and production of DA, particularly in
the extrapyramidal basal ganglia.

30. • Initially in antipsychotic treatment, DA
neurons activate and release more DA,
but following repeated treatment, they
enter a state of physiological
depolarization inactivation, with
diminished production and release of DA,
in addition to continued receptor
blockade. ER, endoplasmic reticulum.

31. 6-CHEMORECEPTOR TRIGGER
ZONE
• Most antipsychotics protect against the
nausea- and emesis-inducing effects of
apomorphine and certain ergot alkaloids,
all of which can interact with central
dopaminergic receptors in the
chemoreceptor trigger zone (CTZ) of the
medulla

32. 7-AUTONOMIC NERVOUS SYSTEM
• Chlorpromazine, clozapine, and
thioridazine have particularly significant
a-adrenergic antagonistic activity. The
potent piperazine tricyclic neuroleptics
(e.g., fluphenazine, trifluoperazine,
haloperidol, and risperidone) have
antipsychotic effects even when used in
low doses and show little antiadrenergic
activity.

33. 8-KIDNEY AND ELECTROLYTE
BALANCE
• Chlorpromazine may have weak diuretic
effects because of a depressant action
on the secretion of vasopressin

34. • Chlorpromazine and less potent antipsychotic
agents, as well as reserpine, risperidone, and
olanzapine, can cause orthostatic hypotension,
usually with rapid development of tolerance.
Thioridazine, mesoridazine, and other
phenothiazines with low potency, as well as
ziprasidone, droperidol, and perhaps high doses
of haloperidol, have a potentially clinically
significant direct negative inotropic action and a
quinidine-like effect on the heart (prolongation
of the QTc and PR intervals, blunting of T waves,
and depression of the ST segment)
9-CARDIOVASCULAR SYSTEM

35. • Many antipsychotics enhance the
turnover of acetylcholine Chlorpromazine
and low-potency antipsychotic agents,
including clozapine and quetiapine, have
antagonistic actions at histamine
receptors that probably contribute to
their sedative effects.
10-MISCELLANEOUS
PHARMACOLOGICAL EFFECTS

36. • The most important are those on the
cardiovascular,
• central and autonomic nervous systems,
and endocrine system. Other dangerous
• effects are seizures, agranulocytosis,
cardiac toxicity, and pigmentary
degeneration of the retina, all
• of which are rare
TOXIC REACTIONS AND ADVERSE
EFFECTS

38. • Orthostatic hypotension, which may result
in syncope, falls, and injuries. Hypotension
is most likely to occur with administration
of the phenothiazine depress cardiac
repolarization, as reflected in the QT
interval corrected for heart rate (QTc)
Clozapine has rarely been associated
with myocarditis and cardiomyopathy.
risk of stroke among elderly patients
treated with risperidone and olanzapine
1-ADVERSE CARDIOVASCULAR
AND CEREBROVASCULAR EFFECTS

39. • Extrapyramidal motor system, occur by
high-potency D2-receptor antagonists
(tricyclic piperazines and
butyrophenones)
2-ADVERSE NEUROLOGICAL
EFFECTS

40. • Clozapine and olanzapine; somewhat less
with quetiapine; even less with fluphenazine,
haloperidol, and risperidone
3-WEIGHT GAIN AND METABOLIC
EFFECTS

41. • Mild leukocytosis, leukopenia, and
eosinophilia occurs with clozapine and
less often with phenothiazines
4-BLOOD DYSCRASIAS4-

42. • Phenothiazines, including urticaria or
dermatitis.
5-SKIN REACTIONS

43. • Jaundice, typically occurs with
chlorpromazine
6-GI AND HEPATIC EFFECTS

44. • Chlorpromazine increases the miotic and
sedative effects of morphine and may
increase its analgesic actions.
• The antimuscarinic action of clozapine
and thioridazine can cause tachycardia
and enhance the peripheral and central
effects (confusion, delirium) of other
anticholinergic agents, such as the
tricyclic antidepressants and
antiparkinson agents.
7-INTERACTIONS WITH OTHER
DRUGS

45. • Potentiate the effect of medically
prescribed sedatives and analgesics,
alcohol, nonprescription sedatives and
hypnotics, antihistamines, and cold
remedies.

46. • Goodman and Gillman’s manual of
Pharmacology and Therapeutics
REFERENCES :