3. Drug terminology. Typical(First generation) antipsychotic. Major tranquilizer- a misnomer. Neuroleptics-prominent neurological side effects (EPS). Fig: Chlorpromazine
4. Psychosis & Schizophrenia. John Nash.(1928) SydBarret (1946-2006) Nobel Prize Winner in 1994 Rock star. in mathematics.
5. Psychosis & Schizophrenia. Psychosis : “Cluster of disorders characterized by hallucination and / or loss of contact with reality.” Psychosis disorders : i) Schizophrenia.ii) Schizoaffective disorder.iii) Delusional disorder. Schizophrenia : “Neurological disease that affects a person’s perception,thinking,language,emotionand social behavior.”
6. Psychosis & Schizophrenia. Symptoms may be classified as : Positive – “attention getter” symptoms i.e. hallucinations, delusions, bizarre behavior, disorganized speech Negative– “crippling” symptoms i.e. apathy, lack of motivation, anhedonia Cognitive - i.e. difficulty with attention, memory, and problem solving Disorganized– i.e. disorganized speech, inappropriate affect
8. Structure Activity Relationship. The phenothiazinestructure from the basic nucleus of chlorpromazine. Substitution at position (2) imparts antipsychotic activity Substitution on the nitrogen at position(10) alters potency and adverse effects; the principal substitutions are: aliphatic, piperidine and piperazine.
9. Pharmacokinetics. Absorption: Readily absorbed from the GI tract.Bioavailability varies due to first-pass metabolism by liver. Volume distribution: 20 L/Kg Protein binding : >90% to plasma proteins,primarilyalbumin.
10. Pharmacokinetics. Metabolism : Extensively metabolized in the liver and kidney. It is extensively metabolized by cytochrome P450 isozymes CYP2D6(mainly).Hydroxylation at position 3 and 7 of the phenothaizine nucleus. In urine,20% of chlorpromazine and its metabolized are excreted unconjugated in the urine as unchanged drug. The remaining 80% consists of conjugated metabolites.Themejor metabolites are the monoglucuronide of N-dedimethylchlorpromazine and 7-hyroxychlorpromazine.Approximately,37% of the administered dose of chlorpromazine is excreted in urine.
11. Pharmacokinetics. Route of elimination : Kidney, 37% in urine. Half life :Approximately 30hours. Route of administration: 1.Oral.2.parental.3.Rectal.
16. Dopamine blockade effects. Limbic and frontal cortical regions: antipsychotic effect. Basal ganglia: Extrapyramidal side effects (EPS). Hypothalamic-pituitary axis: hyperprolactinemia.
17. Mechanism of Action. Dopamine receptor blockade in mesolimbic-mesocorticaldopaminergic system. The primary therapeutic action of phenothiazines and haloperidol appears to involve blockade of the D2-receptor, which inhibits adenylylcyclase. Cont….
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19. Pharmacological Effects. 4. Others:i) Increased appetite. ii) Hypothermia. iii) Sedation. On periphery : These effects are not produced by D2 receptor blocking. 1. Antimuscarinic effects:i) Dry mouth. ii) Dry eye. iii) Dry skin. 2.Antiadrenergic effects :i) postural hypertension. ii) Difficulty in ejaculation. Cont…
22. Indications. Psychoses : 1.Management of schizophrenia. 2. As antiemetic. 3. Psychotic depression.(Along with anti-depressant) 4. As sedative. 5.Disturbed behavior in patients. Others : 1.Anxiety. 2. To potentiate hyponotics,analgesics& anaesthetics.
23. Contraindication. Hypersensitive to this drug. CNS depression. Bone marrow depression. Parkinson disease. Sever hypotension. Hepatic impairment. Elderly patients. Dementia patients. In leukopenia.
26. Limitations in treatment with chlorpromazine. No decrease in negative symptoms . Patients often unable to function in society . Require medication – disease is not cured . Drop in number of institutionalized patients . No substitute support system provided .
27. Acknowledgement. Dr. AnupRahman Sir. Prof.Dr. EhsanulBarri Sir. Dr. Joan Heller Brown, PhD Special Thanks. Dip Rabby. Tushar. Ramim And all of my friends for giving me the courage to make that path to step ahead. Ref: -www.drugbank.ca - www.en.wikipedia.org - www.iucr.org