Anti-psychotic drugs work by blocking dopamine D2 receptors in the brain and are used to treat schizophrenia and other psychotic disorders. They are categorized as either typical or atypical, with atypical drugs blocking additional serotonin receptors and being less likely to cause motor side effects. Common types include risperidone, olanzapine, quetiapine, and clozapine. While effective in reducing psychotic symptoms, anti-psychotics may cause movement disorders or other side effects depending on their receptor affinities. Long-term treatment can help prevent recurrence of psychotic episodes.

1. Anti-Psychotic Drugs

2. Overview
 Anti-psychotic drugs-also
 known as neuroleptic drugs
 anti-schizophrenic drugs
 major tranquillizers
 Dopamine receptor antagonists
 May also act on other targets, particularly 5-
hydroxytryptamine (5-HT) receptors

3. Types of schizophrenia
Types Presentation
Catatonic Marked psychomotor disturbances. The patient may
demonstrate rigidity, immobility, or posturing and may also be
withdrawn and silent. At the other extreme is characteristic
excitement such as pacing and shouting. Fluctuations between
these two extremes may occur.
Disorganized Marked incoherence with inappropriate responses or
unresponsiveness. Delusions or hallucinations are disorganized
and fragmented. The patient may giggle, grimace, and act in an
incongruous or silly manner. Hypochondriacal behavior may be
present
Paranoid Most prominent characteristics are delusions of grandeur or
persecution, during which the patient may be extremely
anxious, aggressive, and/or argumentative.

4. Type of schizophrenia
Types Presentation
Residual The patient is not currently acutely psychotic, but has a
history of at least one acute psychotic break and currently
experiences residual symptoms such as vague associations,
illogical thinking, withdrawal, or inappropriate affect. Living
skills may be impaired.
Undifferentiated May incorporate prominent delusions, hallucinations,
incoherence, or grossly disorganized behavior. But overall,
clinical presentation either does not meet the criteria for one
of the specific types or meets the criteria for more than one
type of schizophrinea.

5. Positive and negative symptoms of schizophrenia
Hallucinations Affective flattening
Delusions Alogia
Thought disorders Apathy
Disorganized speech Amotivation
Bizarre behavior Anhedonia
insomnia Asocial behavior
Combativeness Inattentiveness

6. Delusions and Hallucinations
Psychotic symptom Delusion Hallucination
Definition Belief not based on
fact or reality
Perception disturbance
in sensory experiences
of the environment
Types Grandiose
Religious
Somatic
Nihilistic
Sexual
Persecutory
Auditory
Visual
Olfactory
Tactile

7. Mechanism of Action of Anti-
psychotic Drugs
 Antagonists at dopamine D2 receptors
 Also block other monoamine receptors,
especially 5-HT2.
 Clozapine also blocks D4-receptors.
 Anti-psychotic potency generally runs parallel to
activity on D2-receptors
 Anti-psychotics take days or weeks to work,
suggesting that secondary effects
 (e.g. increase in number of D2-receptors in limbic
structure) may be more important than direct effect
of D2-receptor block.

8. Clinical Efficacy of
Anti-psychotic Drugs
 Effective in controlling symptoms of acute
schizophrenia
 Long-term treatment is often effective in
preventing recurrence of schizophrenic
attacks
 this is a major factor in allowing schizophrenic
patients to lead normal lives.
 Not generally effective in improving
negative schizophrenic symptoms

9. TYPICAL vs ATYPICAL
TYPICAL ATYPICAL
Haloperidol, chlorpromazine,
thioridazine
Thiothixene
Fluphenazine
Prochloroperazine
Risperidone
Clozapine
Olanzapine
Quietiapine
ziprasidone
Blocks D2 receptors Blocks D2 and 5-HT2 (risperidone)
Blocks D1 and
5-HT2 (clozapine)
Treats positive symptoms only Treats both positive and
negative symptoms
Causes movement disorders Little or no movement
disorders

10. Atypical Anti-psychotics
 Risperidone
 1st line agent fewer movement disorders than any of the
typical agents
 Higher doses cause movement disorders
 Olanzapine
 1st line agent fewer movement disorders than any of the
typical agents
 Quetiapine
 1st line agent fewer movement disorders than any of the
typical agents
 Clozapine
 Last line of choice
 May result to idiosyncratic granulosis
 No movement disorders but has marked anti-cholinergic
effects

11. Typical Anti-psychotics
 High Potency
 Haloperidol
 minimal anti-cholinergic but major movement
disorders
 Has a depot for prolonged intramuscular dosing
 Thiothixene
 minimal anti-cholinergic but major movement
disorders
 Fluphenazine
 minimal anti-cholinergic but major movement
disorders
 Has a depot for prolonged intramuscular dosing
 Prochloroperazine
 Principally used as anti-emetic

12. Typical Anti-psychotics
 Low Potency
 Chlorpromazine
 Highly sedating
 Thioridazine
 minimal movement effects, non-sedating
Alpha receptor antagonist- hypotension
Less tendency for eps

13. LOW vs HIGH POTENCY
Low Potency High Potency
Chlorpromazine,
thioridazine,
clozapine
Haloperidol,
fluphenazine
Sedation,
orthostatic
hypotension,
anticholinergic effects
Extrapyramidal
symptoms

14. Antipsychotic-induced Motor
Disturbances
 Acute dystonia
 4hrs to 4 days
 Sustained muscle spasm anywhere in the body
 Tx: Diphenhydramine,benztropine,trihexyphenidyl,
amantadine
 Parkinsonism
 4 days – 4 mo.
 Resting tremor
 Tx: benztropine ,anticholinergic
 Tradive dyskinesia
 Involuntary movement of lips, head limbs tongue and trunk
 4mo-4yr
 Typically irreversible once sets in
 Akathisia
 Restlessness, getting up and sitting down
 Tx: lower medication dose,BB,BZ, anticholinergics
 Neuroleptic Malignant Syndrome
 Life-threatening muscle rigidity, fever
 Tx: cool patient, hydrate with IV fluids
 Dantrolene,bromocriptine, amantadine

15. Pharmacotheraphy for TD
 Reserpine
 Benzodiazepines
 Baclofen
 Valproic acid and derivatives
 Vitamin E

16. Adverse effects by receptor affinities
Receptor antagonized Adverse effect
Histamine (H) Sedation
Serotonin (5-HT) Weight gain
Dopamine (D) Extrapyramidal symptoms
hyperprolactinemia
Muscarinic (M) Anticholinergic effects
Cognitive/memory impairment
Tachycardia
Alpha (α) Orthostatic hypotension
Reflex tachycardia

17. Unwanted Effects of
Anti-psychotic Drugs
 Side-effects (dry mouth, blurred vision,
hypotension, etc.)
 result from blockade of other receptors
 α-adrenoceptors and muscarinic acetylcholine
receptors.
 Obstructive jaundice may occur with
phenothiazines.
 Cause agranulocytosis as a rare and serious
idiosyncratic reaction.
 With clozapine, leucopenia is common and
requires routine monitoring.

18.  OTHER ADVERSE EFFECTS:
 Agranulocytosis- clozapine,
chlorpromazine
 Pigmentary retinopathy- thioridazine
 ECG changes- prolonged QT interval-
ziprasidone

19.  Other uses of antipsychotics:
 Antiemetic (blocks dopamine receptors)-
prochlorperazine
 Intractable hiccups- chlorpromazine
 Pruritus (antihistamine)- promethazine
(Zinmet, Thaprozine)

20. CHEMICAL CLASSES
 Phenothiazines
 Aliphatic- chlorpromazine
 Piperazine- fluphenazine
 Piperidine- thioridazine
 Thioxanthenes- thiothixene
 Butyrophenones- haloperidol
 Dihydroindolines- molindone
 Diphenylbutylpiperidines- pimozide