Schizophrenia is a chronic mental disorder involving breakdowns in thought, emotion and behavior. The document discusses antipsychotic drugs for treating schizophrenia, including typical and atypical drugs. Typical antipsychotics include phenothiazines and butyrophenones like haloperidol, while atypical drugs include clozapine, risperidone, olanzapine and aripiprazole. While both types can effectively treat schizophrenia, atypical drugs have fewer motor side effects but higher risks of weight gain and metabolic issues. The choice of drug depends on individual factors and side effect profiles.

1. Antipsychotic Drugs InAntipsychotic Drugs In
SchizophreniaSchizophrenia
Vinod Mamraj
Saini
309 A

2. What is Schizophrenia ?
• A chronic mental disorderinvolving a
breakdown in the relation between
thought, emotion, and behavior, leading
to faulty perception, inappropriate actions
and feelings, withdrawal fromreality and
personal relationships into fantasy and
delusion, and a sense of mental
fragmentation.

3. What’s going on in Brain ?
• The Dopamine HypothesisThe Dopamine Hypothesis
Schizophrenia results from excess activity of dopamine
neurotransmission in Mesolimbic and Mesocortical
Pathways because:
a) All antipsychotic drugs block dopamine receptors.
b) Higher levels of dopamine receptors measured in brains
of schizophrenics by PET.
c) Stimulant drugs which act through dopamine can
produce schizophrenic-like behaviors
(eg.amphetamines).

7. How to cure it ?
Psychotic diseases are life long and it is
preferable to prevent the psychotic
episodes than to treat them.
* * There is NOCURE * *
Therefore , Antipsychotic DrugsAntipsychotic Drugs drugs are
of 1st
choice !!

8. Classification of AntipsychoticClassification of Antipsychotic
DrugsDrugs
(A)Typical antipsychotics
1. Phenothiazines ( Chlorpromazine, Perphenazine,
Fluphenazine, Thioridazine)
2. Thioxanthenes ( Flupenthixol, Clopenthixol)
3. Butyrophenones ( Haloperidol, Droperidol)
(B) Atypical antipsychotics
1. Clozapine ,
2. Risperidone ,
3. Amisulpiride ,
4. Olanzapine,
5. Aripiprazole

9. Which Type of Drug to Choose ?
• According to high-quality studies that have compared newer and older drugs have
generally found that newer atypical antipsychotics are not any more effective than older
typical antipsychotics (such as haloperidol), at least for initial treatment of first-episode
schizophrenia.
• Similarly, for treatment of children and adolescents with schizophrenia, atypical and
typical antipsychotics appear to be equally effective, but atypical antipsychotics,
particularly clozapine and olanzapine, carry a higher risk for metabolic side effects.
• Side effect profiles between typical and atypical antipsychotics are different. Both
groups cause extrapyramidal side effects (including muscle stiffness, tremors, and
abnormal movements), but the newer atypical drugs do not seem to cause them as
often.
• However, the atypical antipsychotics pose a higher risk for weight gain, which can lead
to diabetes as well as heart disease.

10. • Most antipsychotic medications are approved
only for adult patients.
• Some atypical antipsychotics (such as
risperidone, aripiprazole, olanzapine, and
quetapine) are approved for treatment of
schizophrenia in adolescents (ages 13 - 17
years).

11. What Indian Psychiatrists
Think ?
• Although anti-psychotic medications are available in
India since a long time, little is known about the
prescription patterns of Indian psychiatrists.
1. An email survey of 168 psychiatrists,.
2. The three most commonly prescribed anti-psychotics
were risperidone, olanzapine, and haloperidol.
It was also found that typical anti-psychotics
comprise of 25.15% of all prescriptions
In about 22.36% of the cases the psychiatrists
were using more than one anti-psychotic
in the same patient.

12. Haloperidol !! But Y ?
• Haloperidol, the most-studied antipsychotic in delirium
treatment, often is the drug of choice because :-
1. high potency,
2. low sedative effect,
3. few anticholinergic side effects,
4. minimal cardiovascular side effects,
5. no active metabolites, and
6. multiple administration routes.

13. How it works ?
• It can bind to dopamine D1 and D2 , 5-HT2, histamine
H1 and α2 adrenergic receptors in the brain.
• The efficacy of neuroleptics is thought to be due to
antagonism of dopamine receptors in the mesolimbic
and mesofrontal systems.
• The adverse effects of typical neuroleptics include
tachycardia, impotence and dizziness, and these
unwanted effects are caused by non-selective interaction
at the α adrenoreceptor.
• Other adverse effects include and sedation and weight
gain, which is due to
histamine H1 receptor blockade.
• Haloperidol's negligible affinity for histamine H1

14. Haloperidol

15. Haloperidol
• Pharmacokinetics:-
1. The bioavailability of oral haloperidol ranges from 60–
70%.However, there is a wide variance in reported mean
Tmax and T1/2 in different studies, ranging from 1.7 to
6.1 hours and 14.5 to 36.7 hours respectively.

16. RisperidoneRisperidone
 Combination of D2 + 5-HT2 receptor blockade.
 In addition it has high affinity for α1, α2 and H1
receptors; blockade of these may contribute to efficacy
as well as side effects like postural hypotension.
 Risperidone is more potent D2 blocker than clozapine;
extrapyramidal side effects are less. Prolactin levels rise
during risperidone therapy, but it is less epileptogenic
than typical agents.
 Caution: increased risk of stroke in the elderly.

18. OlanzapineOlanzapine
 Broader spectrum of efficacy covering schizo-affective
disorders.
 Resembles clozapine in blocking multiple monoaminergic
(D2, 5- HT2, α1, α2) as well as muscarinic and H1 receptors.
 Both positive and negative symptoms of schizophrenia
appear to be benefited.
 Monotherapy with olanzapine may be as effective as a
combination of lithium/valproate + benzodiazepines.
 Incidence of stroke may be increased in the elderly.
 Agranulocytosis has not been reported with olanzapine.

19. Do you Know ?? , What ?
Vatslav Fomich Nizhinsky
Russian-
born ballet dancerof
almost legendary fame,
celebrated forhis
spectacularleaps and
sensitive interpretations.

20. !! спасибо за внимание !!