anti psychotic drugs

2. › General concepts
› Mechanism of action
› Indications
› Side effects
› SPECIFIC ANTIPSYCHOTIC MEDICATIONS
› Conclusion
Contents:-

3. › They have an equal or greater affinity for D2
receptors than for 5-HT2 receptors
› Antagonism of D2 receptors in mesolimbic
pathways suppress the positive symptoms of
Schezophrenia.
› Blockade of D2 receptors in the basal ganglia is
responsible for parkinsonian and other
extrapyramidal side effects of anti psychotic
drugs
General concepts for typical

4. › The exact mechanism of action of antipsychotic drugs
is unknown.
› According to the dopamine theory of schizophrenia,
positive symptoms are the result of an overactivity in
the mesolimbic dopamine pathway.
› first-generation antipsychotics are D2 antagonists. As
a result, they reduce dopaminergic neurotransmission
in the four dopamine pathways.
Mechanism of action

6. › Psychomotor Agitation: High potency APMs
(Haloperidol) are used because injections are available
› Schizophrenia: Treatment of choice for acute psychotic
episodes & for prophylaxis
› Other Psychotic Disorders: Treatment of Psychoses &
Cognitive disorders due to general medical conditions
& substances, delusional disorder, brief psychotic
disorder,
Indications

7. › schizophreniform disorder & other rarer psychotic disorders
› ! Mood Disorders: Treatment of Agitation & Psychosis during
mood episodes
› ! Sedation: Useful when Benzodiazepines are contraindicated
(specially in older
› patients) or as an adjunct during anesthesia
› ! Movement Disorders: Treatment of choice for Huntington
disease & Tourette disorder

8. Side effects

9. TARDIVE DYSKINESIA (TD)
› Characterized by irreversible Choreoathetosis & other involuntary
movements
› Movements often occur first in the tongue or fingers & later involve the
trunk
› Movements disappear during sleep
› Etiology may be a form of “chemical denervation hypersensitivity”,
which is caused by chronic Dopamine blockade in the basal ganglia
› Older Patients who take high doses of older APMs for long periods of
time are at highest risk & movements gradually worsen with continued
use
› o Treatment
› ! Stop older APMs
› ! Use newer APMs

11. › ! Chlorpromazine (Older Low-Potency D2)
› o Highly Sedating. More Hypotension. More Anticholinergic effects
› o Low frequency of EPS
› o Few remaining indications for primary selection
› ! Haloperidol (Older High-Potency D2)
› Less Sedating. Less Hypotension. Less Anticholinergic effects
› High frequency of EPS
› Remain useful for Rx of Acute Agitation, especially via IM injections
› Long acting (Haloperidol: once q 4 wks & Fluphenazine: once q 2
wks)
SPECIFIC ANTIPSYCHOTIC MEDICATIONS

12. › First-generation antipsychotics are also known as: typical
antipsychotics, conventional or classic antipsychotics and
dopamine antagonists.
› FGAs reduce dopaminergic neurotransmission in the four
dopamine pathways by blocking D2 receptors.
› FGAs differ in potency, not effectiveness.
– High-potency: haloperidol, fluphenazine
– Mid-potency: perphenazine, loxapine
– Low-potency: chlorpromazine
Conclusion

13. References
&