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So antipsychotics are a class of drugs used primarily to treat psychotic depression now in order to gain better understanding of mechanism of action of development of psychosis so the monoamine neurotransmitter dopamine the unusual behavior and experiences associated with psychosis now dopamine has four major pathways by which it affects the brain schizophrenia and to mediate
Positive symptoms of psychosis such as delusions thought to be under active in schizophrenia and thus mediate negative number three the nigrostriatal pathway which is system and controls motor function and movement deficiency of dopamine in this dopamine can lead to hyperkinetic movements such as tics and dyskinesias which controls prolactin secretion specifically dopamine
In this pathway enables milk production and is also involved in the control of sexual desire interacts with specific receptors that mediate functional effects of dopamine out of the five d1 and d2 receptors are found in the highest d2 receptors are the most clinically relevant because they are the first generation agents known as typicals and the newer second-generation
Share the same main therapeutic goal that is to block d2 receptors dopamine pathways and thus will block d2 receptors in almost all areas of the dopamine receptors in the mesolimbic pathway reduces positive symptoms such already underactive in schizophrenia may cause worsening of negative symptoms in emotional and verbal expressiveness and social disengagement furthermore
Extrapyramidal disorders tardive dyskinesia and parkinson’s-like symptoms movements lastly blockade of dopamine receptors in the tuberoinfundibular galactorrhea gynecomastia and sexual dysfunction now based on their affinity or low potency the examples of high potency antipsychotics are haloperidol generally speaking the high potency agents produce stronger antipsychotic
Extrapyramidal side effects and greater increase in prolactin levels on the receptor as tightly as the high potency agents and generally affect a range of other receptors including alpha-adrenergic cholinergic and histamine alpha-adrenergic receptors can lead to orthostatic hypotension blockade of mouth blurred vision difficulty urinating and constipation and blockade move
On to the second generation atypical antipsychotics in contrast to appear to block both d2 receptors as well as serotonin receptors subtype 2a receptors may increase dopamine levels in brain areas that need it furthermore allowing for relatively normal dopamine neurotransmission this modest d2 to significantly lower the incidence of extrapyramidal side effects as well as
Examples of atypical antipsychotics are aripiprazole clozapine lurasidone antipsychotics also bind to many other targets including other subtypes of serotonin receptors as well as histamine alpha-adrenergic and muscarinic receptors as a depending on the drug’s receptor binding profile so for example atypical such as clozapine and olanzapine may cause metabolic side effects
Including affinity for h1 receptors such as clozapine olanzapine and quetiapine have significant affinity for alpha-1-adrenergic receptors such as clozapine all second-generation agents risperidone d2 receptors and because of that it has the highest potential to induce the only antipsychotic that can cause serious condition called agranulocytosis cells called granulocytes
Because this condition can be fatal periodic blood thank you for watching i hope you enjoyed this video and as always stay
Transcribed from video
Pharmacology – ANTIPSYCHOTICS (MADE EASY) By Speed Pharmacology
