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Pharmacology 401 b NSAID Mechanism Of Action Aspirin AcetylSalicylic indomethacin diclofenac

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#NSAID Mechanism Of Action #Aspirin #AcetylSalicylicAcid #indomethacin diclofenac

Welcome in the previous video we have seen an introduction to non-steroidal anti-inflammatory drugs let’s continue adding more information here phospholipids example they are present in the cell membrane they are with the help of phospholipase ito converted into arachidonic acid anna chronic acid can be acted upon by coxswain cox-2 or lipo oxygen ease now coxswain

Is mainly physiological it is constitutive in many tissues and it will help in homeostatic functions by the production of some prostaglandins like pge2 pgi2 pg d 2 thromboxane a2 and pg f 2 alpha so on and so forth these will maintain the gastrointestinal tract the renal tract blood vessels now coming to cox – it is mainly induced during inflammation actually it

Is considered in some parts of the body very minor so you can think of it mainly as an induced enzyme it is used by cytokines and it will produce some mediators which will mediate inflammation and it will cause pain inflammation and fever mainly here you can say that pge2 is produced in large quantities now let us see what else can happen with arachidonic acid like

For oxygen ease can act on arachidonic acid and give you new katrin’s okay so we have added to what we have studied in the previous video correct here we have come to the level of understanding lipo oxygen his last video we did not have this we had this now then we have also mentioned all the names of the prostaglandins pge2 pgi2 pgd – thromboxane a2 and pg f –

Alpha can you tell me what each of these first four prostaglandins do prostaglandin e2 mainly it is the homeostasis gi protection kidney function platelet function regulation of blood flow this is the homeostatic functions of it now coming to pgi2 here you can remember both of these pgi2 and pgd to cause vasodilation they will help the blood to flow inhibition of

Platelet aggregation and then in pg d2 you have bronchoconstriction remember the bronchoconstriction happens in eg d2 now coming the thromboxane a2 there is platelet aggregation and regulation of blood flow this is actually platelet aggregation so this is a opposite effect of pgi2 now coming to pg f 2 alpha you have seen this it lowers intraocular pressure right

This you have seen as a treatment for glaucoma this is actually showing you lot of actions of prostaglandins as drugs you can maintain the patency of ductus arteriosus this is something that you can remember for the maintenance of ductus arteriosus you can use prostaglandins for glaucoma you can use prostaglandins you can use it for pulmonary hypertension erectile

Dysfunction for abortion for induction of labor so basically this is going to induce labor so you can use it for abortion so similarly you have many functions of this but here we are not concerned about this we’re concerned about non-steroidal anti-inflammatory drugs which will stop the action of prostaglandins correct so now let us look at the action of aspirin

So you will have to explain all this and then see that aspirin is a non-selective cox inhibitor right it inhibits both cox-1 and cox-2 so the mechanism of aspirin is it is inhibiting both cox-1 and cox-2 so aspirin actually is short form for acetyl salicylic acid please remember that and it is going to be your non selective cox inhibitor it is coming under the

Chapter with chapter or quoits under that non-steroidal anti-inflammatory drugs right and it is an irreversible inhibitor of cox please remember this it’s an irreversible inhibitor of cox rest of the nsaids which we are going to study are reversible now you have seen in the last video that in low doses it causes an anti platelet effect in 2 to 3 grams per day it

Causes an analogous ik and antipyretic effect and in high doses it causes anti-inflammatory action now let us look at the details how exactly does it do this so here you can see aspirin acetylsalicylic acid it is a proto dry type drug for this group and non-steroidal anti-inflammatory drugs which is the prototype drug aspirin as a time salicylic acid so we told

You that it is irreversible inhibitor of course now let us look at the anti platelet or the antithrombotic effect so you can see that at low doses only it will work as antiplatelet what will happen if you do high dose if you give high dose both the pgi 2 and thromboxane a2 will get inhibited at c at low dose what happens pgi 2 will be there only thromboxane a2 is

Inhibited but if you give high dose of aspirin then even pgi2 will get inhibited so you can see this diagram it will help you understand see low dose of aspirin thromboxane a2 is inhibited high dose what happened 2 to 3 gram per day if you give both pgi2 and p the thromboxane need to get inhibited pgi2 causes vasodilation and inhibits platelet aggregation do you

Thromboxane a2 causes vasoconstriction and promotes platelet activation so both are like acting against each other so if you want to have an antiplatelet activity then bitter you have a inhibitor of thromboxane it only let the cyclones be there so that they will nicely the blood will fight it the cycling’s you have to retain don’t kill the cycle is also fine this

Is the low dose aspirin now let us move on to the next effect so if you give 2 to 3 gram per day what will happen you’ll have an analgesic effect antipyretic effect now let us look at both of these and as this effect is written here anti-pirate this is written here first of all analysis it’s for minor pains not for made japanes like doctor our pe not a road traffic

Accident or major things like that this is only for small pains dysmenorrhea painful menstruation pain associated with any inflammation then mosquito musculoskeletal pain such things only you can use nsaids okay so how are these in is eid is going to work first of all they’re going to have a mainly a peripheral action the pet the prostaglandins are inhibited these

Prostaglandins we’re stimulating the peripheral nerve right so you’re going to prevent the sensitization of peripheral knob so no pain sensation not you know not for a high pain but yeah for normal thing now coming to the central actions then subcortical site also the inc the pain threshold is increased so you can tolerate pain up to some threshold this is not going

To be as effective as an opioid analgesic but however it will help you in managing day-to-day pain from this menorah or inflammation or musculoskeletal pain the good thing about these drugs are they relieve the pain without causing sedation respite respiratory depression tolerance or dependence great right now let us move on to the antipyretic effect down here you

Can see the antipyretic effect so that is the temperature the fever should not have increase or the temperature body temperature should not increase is the best thing is it will reduce fever and it will not the effect the normal body temperature also this is a good thing now how does it do this in the hypothalamus you have a thermo regulatory center remember where

It is acting in the hypothalamus there’s a thermo regulate recent center this if this is disturbed then only you will have fever now what this nsaids do it’s going to reset a reset the hypothalamic thermostat so it’s were going to work on the thermostat of the thermoregulatory center which is present in the hypothalamus and it is going to reset it and hence it is

Going to reduce the elevated body temperature the best part is it is not going to affect normal body temperature how is the heat loss promoted by causing vasodilation in the cutaneous via blood vessels and also it increases the sweating so they promote heat loss by causing cutaneous weight so dilation and sweating okay so again you have to write this word inhibition

Of prostaglandins in hypothalamus right where are the prostaglandins being inhibited here in the hypothalamus okay the last thing we will look in this video is the anti-inflammatory effect the all the other effects we will see in the next video so we what and all we saw till now auntie platelet effect auntie a logistic effect antipyretic effect now we are going

To look at the fourth one and the inflammatory effect the main four right anti-inflammatory effect you know you have to give a little higher dose that is four to six gram per day in divided doses these drugs are only symptomatic relief of the infection inflammation it is not going to actually remove the cause of the inflammation right only the symptomatic relief or

The symptoms are going to be relieved for you what are the sinus symptoms that will be relieved pain tenderness swelling vasodilation youko side infiltration etc so what you should know cox-2 should be inhibited here right because these are anti-inflammatory so pain will be inhibited tenderness swelling will be reduced so dilation will be reduced extra okay now a

Main thing you have to write here it will not affect the progression of the underlying disease now let us go how does it work it inhibits the prostaglandin synthesis which will definitely write that also other mediators of inflammation will be reduced how because prostaglandin main thing is cut off there so brandi kind unless may make histamine less make serotonin

Less make then look at this inhibit the granulocyte and her adherence to the damaged vasculature so there be modulation of the t cell function stabilization of the lysosomal membrane inhibition of chemotaxis so can you just see again what are all of the anti-inflammatory actions inhibition of the prostaglandin synthesis inhibition of the inflammatory mediators like

Braddock einen histamine serotonin then you have the inhibition of granulocytes adherence to the damaged vasculature cause a modulation in the t cell function inhibit the chemos tasks chemotaxis and stabilize the lysosomal membrane right this is all we saw in this video let us revise at low dose it will cause antiplatelet effect at two to three gram per day in

Divided doses it will cause an algaecide to affect an antipyretic effect at four to six grandpa dailykos anti-inflammatory effect come back we will see all the other effects also

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Pharmacology 401 b NSAID Mechanism Of Action Aspirin AcetylSalicylic indomethacin diclofenac By MBBS VPASS