#first #dose #effect Yohimbine
You welcome people now we want to look at the anti adrenergic drugs correct so far we have seen watered on cholinergic drugs anticholinergic drugs adrenergic trucks now we want to look at aunty antonov chick drugs so in that you can have alpha blockers or beta blockers everything sounds strange to you right meet see we are looking at the autonomic nervous system
In that parasympathetic and sympathetic currently we are in the and be sympathetic or the sympathy don’t lytic drugs okay sympathetic sympathetic system basically fear fight flight or fright okay so the receptors are alpha or beta currently we are discussing anti sympathetic or sim battle lytic trucks and the adrenergic trucks in that there could be alpha blockers
Or beta blockers currently we’re discussing what alpha blockers now what happens if you block alpha let’s see if alpha blockers are blocked sorry if alpha receptors are blocked or alpha action is block what will happen so better let us go to the receptor diagram and check so let us say alpha is blocked the person can’t have it rests if alpha is blocked there can
Be way so dilation so there can be postural hypotension alpha is blocked if alpha is blocked urine sphincter sphincter cannot work so emptying of bladder uterus cannot contract wow so you understood everything night just by looking at the receptor locations you can know if alpha 1 is blocked what it all happens right even ejaculation erection could be affected
Like what happens if alpha 2 is blocked then there will be more insulin cos alpha/2 less insulin you want to block alpha 2 so more insulin okay so is it clear like if we do alpha block what and all will happen in the system currently we are here we’re looking at the alpha adrenergic blocking drugs here as you can see we have non equilibrium type and equilibrium
Type non equilibrium type only one drug is there phenoxy benz mean everything else is equilibrium type o competitive antagonist yeah so just look at this phenoxy benza mean it is used to treat for your chromos saitama this is a tumor of the adrenal gland so in the adrenal medulla resells there will be a 2-man excess catecholamines will be secreted okay because
Of which they be persistent hypotension to treat that they will give phenoxy benza mean okay remember phenoxy benjamine can be given to give to treat pheochromocytoma so alpha blockers are given to treat pheochromocytoma then went all i mean let us come to the non selective alpha blockers then we’ll go to alpha 1 selective blockers alpha 2 selective blockers now
First of all non selective blockers all the alpha stuff will be blocked example in that and got alcohol you should know then you should know imidazolium like friend toll i mean these so you should know okay chlorpromazine is also an chlorpromazine you have seen in antipsychotics correct one skin yes it is an anti-psychotic so it is also coming under it now for
Non selective alpha blocker okay so these are got alkaloids alkaloids like err got a mean ergo tox sign okay all these we are currently here guys wake up a few are asleep we are looking at air got alkaloids these are rivera we non-selective alpha blockers and that l got alkaloids you have got a meal ergo taksim these are like ox dosing they stimulate uterus okay
They are like oxytocin remember had got alkaloids okay then going on to phentolamine phentolamine is actually an antidote if there is a cheese reaction because of mao mao a inhibitors because these are nothing but antidepressants if you give these mao a inhibitors to treat treat depression you gave this mao-a inhibitor then what happens there could be a cheese
Reaction because what these actually do you know these mao inhibitors look at this this diagram you look at here we are what happens this mao it metabolizes this monoamine oxidase metabolites is noradrenaline serotonin entire mean because of less noradrenaline serotonin the person has become very depressed so they will give an inhibitor of this mao to the patient
Now what happens the ma way is inhibited so noradrenaline serotonin levels increase and the person becomes happy but the problem is the sky remain which was there this tyramine moon level also will increase the stylman comes with things like all these fatty food etc so when tyramine becomes more it is bad for the body there could be two things you should know it
There could be hypertensive crisis which could be fatal and there could be cerebral vascular accidents okay so because of these two hypertensive crisis and cerebrovascular accidents this cheese reaction is dangerous and the the treatment here is phentolamine went on a meal is nothing but as non-selective alpha blocker clear right so you saw how it got all linked
To the depressants chapter so antidepressant when you give if you are giving mao a inhibitors remember the person can go into cheese reaction and the solution for that will be phentolamine phentolamine is actually a amida’s only and it is a non selective alpha blocker so you are pretty aware that we are looking at the alpha adrenergic blocking drugs correct now
We have list this one went alamein we have finished chlorpromazine is antipsychotic we are not going to details of that now then we will go to the selective one in selective’s you have alpha one selective and alpha two selected let us look at alpha one selected now alpha one selective blockers these are all ending with the posen posen so prazosin terra’s olson
Doxa zosyn alpha is ocean except translucence said low dosage tamsulosin and all the name we have heard a lot so remember prazosin taras olson dock salvo same time solution for names you can remember for now say the names prazosin tamsulosin then there are those in oxytocin okay these are all alpha one blockers they block only alpha 1 then you have alpha 2 blocker
Alpha 2 blocker you have yo combine okay about rizzo seen you should know that it has first dose effect first dose effect means because this is an alpha one blocker what happens there can be way so dilation correct because alpha one is responsible for weeks of construction however alpha one block means that can be no vasoconstriction there be meso dilation if
There is vasodilation what happens especially the art plays in this case they get more dilated than the veins and hence the person can have dizziness and he can think this is postural hypotension this is first dose effect subsequently the person will learn about it and they will tolerate it but the first dose effect is more for prazosin so you should keep they
Ask you in exam first dose effect you should explain this plan so same costos effect you remember this diagram drag alpha one causes vasoconstriction and m3 causes vasodilation if alpha one is blocked then this place of construction cannot happen so there will be v so dilation so when there is v so dilation there will be reduction in blood pressure and hence the
Person will have postural hypotension so as soon as he stands up he may faint or make him eat free dizzy when he takes this tablet so you should tell that person get up slowly okay if you are giving him up alpha-1 blocker okay guys these this class addiction is actually taken from the textbook kb k d3 party okay three a party textbook textbook is the source for
All this information now coming to tara’s olson and boxes olson now tara sousa and oxytocin they are used actually to treat urinary retention okay so in benign prostate hypertrophy what happens the person prostate has enlarged so he’s not able to void his bladder okay so what happens when you give tara zosyn and oxytocin the smooth muscles will relax wait you
Can see here alpha one is responsible for closing the sphincter right so now if you give this alpha one block sprinter will open correct so there will be unary outflow so if a person has been in benign cross-strait hypertrophy urinary obstructions that’s things you can give this alpha one block it will only help the smooth muscles etc but there is no effect on
The prostate size prostate size will be same with me okay so let’s go back there now so we are looking at alpha adrenergic blocking drugs we have finished almost everything so let’s revise alpha one blocking drugs you have phenoxy been zameen which is used to create treat for your chromos itoma other than that you should know non-selective alpha one selective
And alpha 2 selective non-selective you should know air got alkaloids phentolamine and chlorpromazine it got alkaloids are just like oxytocin they as neutron stimulus phentolamine is used to treat cheese reaction which is caused by your moclobemide that is in a or a inhibitor one confusion is alpha one causes uterus contraction and here if you are blocking it
Then there should be no contra of uterus then how it will stimulate the uterus and that solution is something like it got alkaloids they are partial agonist and antagonist sometimes they are the ms antagonist another place so what happens they will in help in reducing postpartum hemorrhage that is after delivery and also they’re used to treat migraine don’t more
Than much about our got alkaloids at this point okay so what else guys phentolamine cheese reaction you can treat cheese reaction process in there are thousand oxytocin you can use two if there is a benign process with hypertrophy and the person is not able to avoid the bladder you can give this remember the side effects will be posted on hypotension etc what
Will be the side effects of black blocking alpha all those side effects will be there postural hypertension then delaine ejaculation all those things will be that okay so what ends to know he or she try cyclic empty the prison’s well they also have alpha blocking effect so you should know that tricyclic antidepressants also have this kind of alpha block effect
So guys summarizing we have looked at alpha blocking drugs non selective alpha one selected block alpha to select a block non selective block we have mainly the phentolamine which is used as a treatment for cheese reaction then we have chlorpromazine used as antipsychotic all of them will have for alpha one block then you have tricyclic antidepressants also will
Have alpha one block then you have alpha 1 selective block alpha 1 selective block will be process and thorough zosyn doctors olson and tan solution these are used to treat urinary retention in hyper benign hyper benign prostate hypertrophy then you him by niz alpha to selectively block up not use much ok alpha to block a not use much okay then you should have
Been a phenom in phenox amen the mean is used to treat pheochromocytoma that’s all for now this much is enough guys come back to the next video hope you enjoyed this video bye bye next video we will look at beta blockers okay
Transcribed from video
Pharmacology 130 a Alpha blockers Adrenergic PhenoxyBenzamine Phentolamine Prazosin Terazosin By MBBS VPASS
