chapter 25 antipsychotic drugs

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Chapter 25 Antipsychotic Drugs. Antipsychotic drugs. Schizophrenia 精神分裂症 literal translation “split mind” separate emotional side from intellectual side emotional & cognitive processes don't function together a group of severe disorders characterized by: - PowerPoint PPT Presentation


  • Chapter 25 Antipsychotic Drugs

  • Antipsychotic drugsSchizophrenia literal translation split mindseparate emotional side from intellectual sideemotional & cognitive processes don't function togethera group of severe disorders characterized by:disorganized and delusional thinkingdisturbed perceptionsinappropriate emotions & action

  • Psychotropic Drugs Classificationantipsychotic drugs neurotropic drugs antimanic drugs antidepressants anxiolytics

  • Nature of psychosis /schizophreniaThe dopamine hypothesis excessive dopaminergic activity plays a role in the disorder.The enhancement of function of 5-HT2Dopaminergic SystemsThe nigrostriatal pathway (coordination of voluntary movement )

  • Mesolimbic- mesocortical ( behavior ) Tuberoinfundibular- pituitary system (endocrine) The medulla oblongata (vomit)Medullary - periventricular pathway ( eating behavior)

  • Antipsychotic drugs ClassificationPhenothiazin ( chloropromazine )Thioxanthenes (chlorprothixene )Butyrophenones (haloperidol )Others

  • Antipsychotic/Neuroleptics Phenothiazin chlorpromazine (wintermine ) Pharmacologic effectsblocking DA2 M 5HT2 H1 receptors

  • neuroleptic effect ()

    Blocking Mesolimbic system and mesocortical D2-R More effective for treating positive symptom Substantia nigra- corpus striatum ---- extrapyramidal effects Node-funnel --- endocrine system action

  • powerful antiemetic action blocking CTZ D2-R (small dosage) directly inhibiting vomiting center (large dosage)altering temperature-regulating mechanisms decrease temperature no matter normal or high temperature body temperature varies with the environment

  • autonomic NS effects blocking -R vasodilatation epinephrine reversal blocking M-R atropine-like action endocrine system action increasing prolactin secretion inhibiting gonadotropic hormone growth hormone secretion

  • Therapeutic usesschizophrenia more effective in treating positive symptoms severe nausea and vomitinguseful in the treatment of drug-induced nauseahypothermic anesthesia and artificial hibernation chlorpromazine promethazine pethidine

  • Adverse effectscommon adverse effects CNS depression (drowsiness, indifference) M-R block (blurred vision, dry mouth) -R block (orthostatic hypotension ) extrapyramidal reaction Parkinson's syndrom akathisia acute dystonia treated by antimuscarinic drugs (artane, )

  • tardive dyskinesia treated by antidopamine drugs (clozapine,)Neural antagonist severe symdromedrug-induced mind abnormality convulsion and epilepsyallergic reaction acute hypogranulocytosis ()cardiovascular and endocrine system reactionacute poisoning

  • Thioxanthenes chlorprothixene Butyrophenones haloperidol Otherspenfluridol clozapine

  • Clozapine () Benzodiazepines Pharmacological effectBlocking 5-HT, D2 receptorStrong efficacy, rapidlyNo extrapyramidal reaction Blocking H1, M andreceptorhypogranulocytosis

  • Antimanic drugsBipolar affective disorder Cyclic manic attacks In high spirit Overactivity Paranoid thoughts

  • Lithium Carbonate Clinical use Based on the Li+ treatment for bipolar disorder manic phase particularly prophylactic Li may block both manic and depressive

  • Adverse effectsGI tract nausea, vomiting, diarrhea mental confusion, tremor, aphasia , choreoathetosis , comaManagement of Li overdosage:peritoneal dialysisor hemodialysisiv NaCl

  • AntidepressantsTricyclic antidepressants NA 5-NA reuptake inhibitor NASerotonin reuptake inhibitor 5-Others

  • Tricyclic antidepressants imipramine Action CNS: inhibit NA and 5-HT reuptake normal individals: depressant effect depression: mood elevation, spirit excitationThe onset of the mood-elevation is slow, 2~3 weeks autonomic nerve system Blocking M-R effects: blurred vision, dry mouth, constipation, urinary retention

  • cardiovascular system low blood pressure arrhythmiaClinical uses depression various kindsespecially endogenousinvolutional depression enuresis in children older than six phobic anxiety ()

  • Adverse effectsdry mouth, mydrasis, blurred vision, orthostatic hypotension agranulocytosis urinary retentionocular pressure increase ContraindicationProstatic hypertrophy and glaucoma

  • NA reuptake inhibitordesipramine , inhibit NA reuptake selectively treat mild, moderate depression sedation and hypotension side effect is slight compared with imipramine overdose can cause low blood pressure, arrhythmia, dry mouth, constipation

  • 5-HT reuptake inhibitorfluoxetine , inhibit 5-HT reuptake selectively treat depression: improve attention emotion adverse effects: GI tract reaction, tremor risk of life-threatening serotonin-syndrome co-administered with MAO inhibitors

  • MAO inhibitor Phenelzine inhibit MAO nonselectively treat mild, moderate depression, also phobic states side effects: orthostatic hypotension, nausea, headache, insomnia, tremor, hallucination not co-administered with tricyclic antidepressants and food rich of tyramine

  • MAOI & Dietary Tyramine


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