Drugs inhibiting metabolism of Dopamine – Parkinson’s Disease ( Part 5 ) – CNS Pharmacology

📌𝐅𝐨𝐥𝐥𝐨𝐰 𝐨𝐧 𝐈𝐧𝐬𝐭𝐚𝐠𝐫𝐚𝐦:-

Now let me discuss the other group of drugs inhibiting the metabolism of the dopamine now remember this dopamine it is metabolized by two important enzymes that is mano-a-mano oxidase and as well as the co empty these two enzymes monoamine oxidase and catechol or methyl transferase they are the enzymes which will metabolize the dopamine so first let me discuss

About the comt inhibitors right let me discuss about the comt inhibitors now if you take this comt inhibitors this enzyme metabolizes the dopamine as well as levodopa to 3 omd right this comt we metabolize the dopamine and as well as even the levodopa to 3 ortho methyl dopa right in the presence of this enzyme so whenever this enzyme is there the levels of the

Dopamine in leawood opa they are getting reduced and thereby they are getting converted into 300 methyl dopa that is ortho meta dope-ass so now what you have to do is you have to give a group of drugs which will inhibit that particular comt enzyme so we have two drugs for that that is one we have toll capone and the other drug what we have is the n takapuna right

The tool couple and as well as the enter capone now this particular told capone and as well as enter capone what they do they inhibit that particular comt enzyme and thereby your dopamine and liver dopa they are not converted into 3 o methyl dopa and thereby the levels of the levodopa they are increased so the sloboda power levels which ever are increased this

Evo dopa we cross the blood-brain barrier and that is useful for the treatment of parkinsonism now remember this particular drugs right this comt inhibitors these can be given in combination with levodopa plus carbidopa so these drugs these can be given in combination with levodopa plus carbidopa so what you have to do is these comt inhibitors they can be given

Along with levodopa plus fat we’d open right levodopa plus carbidopa alright so this combination what it will do this combination will inhibit the dopa decarboxylase and this combination will also inhibit this comt enzymes and thereby the levels of the levodopa will be increased and once the levels of the levodopa increased they will cross the blood-brain barrier

And the levels of the levodopa it will increase within the brain right otherwise what will happen is whenever you are giving only levodopa plus carbidopa right when when you are giving only levodopa plus carbidopa what will happen is that levodopa in the presence of comt enzyme is converted into 3 ohm ethyl dopa right so 300-meter l-dopa which is formed by the

Metabolism of the levodopa it competes with the liver of by itself for the entry into the brain right the 300-meter l-dopa which is formed by the metabolism of the liver it competes with the levodopa itself for the entry into the brain so when you use this particular component as well as enter capone this enzyme is inhibited then there is no formation of the 300

Methyl dopa all right so and what you have to remember here is you think we are having two drugs that is 12 upon and as well as enter capone told capone remember this will inhibit the comt right this will inhibit the comt enzyme both in the periphery right both in the periphery and as well as within the center right it will innovate this comt both in the periphery

And as well as the center where as you take this enter capone enter capone this drug will act only in the periphery right this drug will act only in the periphery this is a very very important point right so what is a point that needs to be remembered here is the major beneficial effect of these drugs in parkinsonism is due to the peripheral inhibition of the

Cont right the major beneficial effect of these drugs is due to the peripheral inhibition of the comt all right next among these two drugs that is troll capone and as well as inter capone which is more potent you’re torque upon is more potent and not only more potent this is also longer acting right this is also longer acting so the torque upon which is formed

This is more potent and as well as longer acting then compared to that of the inter capone but even though 12 capone is more potent and longer acting this is not preferred why because the tall capone is associated with severe hepatotoxic effects this is associated with cba hepatotoxic effects so that is the reason why this 12 capone it is not preferred right so

This is about your co mp inhibitors so remember the comt inhibitors we have two important drugs that is troy capone and as well as inter capone so this comt inhibitors will inhibit this enzyme comt and thereby the levodopa is not converted into 300 method opa and this comt inhibitors they are given in combination with the levodopa plus carbidopa why because if

We use only evo 2 / + carbidopa this levodopa in the presence of enzyme comt is converted into 300 methyl doper right and the 300 methyl dopa which is formed will be in competition with the levodopa for crossing the blood-brain barrier so when you use the comt inhibitors there is no question of the formation of 300 methyl dopa and in between the comparison of

These two drugs the 12 upon it is it will inhibit the co mp both in the periphery and as well as in the center whereas in takapuna it will inhibit the co empty only in the periphery right the major role of these drugs in the treatment of the parkinsonism is inhibition of the comt in the periphery and you take this toll capone it is more potent and as well as

Longer acting even though it is more potent and longer acting this 12 capone is not used much why because it is associated with severe hepatotoxic effects so that is the reason why this particular toll capone is not used much so we have discussed the cont inhibitors now let me discuss the other group of drugs which will inhibit the mana of minor oxidase so in

The presence of comt dopamine is converted into or levodopa and dopamine it is converted into 3 o methyl opa whereas in the presence of enzyme ma that is mono or minor oxidase this dopamine is converted into dope act that is dihydroxy phenyl acetic acid so now when this mao enzyme is there that is mono this enzyme is there the dopamine levels they get reduced

So what you do is you give it drugs or you give a group of drugs which we inhibit this particular the mayo enzyme right so we have accordingly what is called as ma be inhibitors that is more or more you know oxidase be inhibitors right so so the drugs in this mall be inhibitors are we have saline and the other drug what we have is the wrestling right so jeanne

And as well as misogyny so both of these drugs they are irreversible and selective inhibitors of malobi it reversible and selective inhibitors of mono or minor oxidase be alright now so these drugs they are also given in combination with levodopa plus carbidopa to decrease the dose of levodopa right so these drugs they are given in combination with levodopa plus

Carbidopa mainly to reduce the dosage of the levodopa and thereby reducing the adverse effects associated with the levodopa all right now remember this saline and dressage saline right this saline and rasa helene whenever they are given at normal doses right whenever they are given at normal doses they inhibit only one enzyme that is mao-b so they inhibit only

Mono minor oxidase be at normal doses but however whenever these drugs when they are given in hide right whenever they are given in high doses they will inhibit another enzyme that is mono or minor oxidase a so when you give this particular drugs under high doses they will inhibit a mono or my no oxidase a and this will lead to hypertensive crisis right this will

Lead to hypertensive crisis so this is the problem when you are giving the saline at andres arginine at higher doses and this particular hypertensive crisis which is occurring because of the inhibition of this monoamine oxidase enzyme is what is called as the cheese reaction right is what is called as the cheese reaction right so whenever these drugs are given

In high doses they are also in a bit mono or minor oxidase a and they can lead to hypertensive crisis which is called cheese reaction with substances like tyramine containing foods and serotonin syndrome with prai cyclic antidepressants right so whenever you give this in high doses the two things one hypertensive crisis with tyramine containing food substances

And the other one is the serotonin syndrome right now you take this sailaja lean and wrestling which is more potent remember it is rasa helene which is more potent compared to that of the shalini right more potent compared to that of saline right and the very important property of these drugs is these drugs they are thought to reduce the disease progression

Right they reduce the disease progression right so this is about your monoamine oxidase be inhibitors remember the monoamine oxidase enzyme will convert the levodopa our dopamine to dope act that is dihydroxy finite acetic acid so what you do is you give a group of drugs which will inhibit this mono or minor oxidase be enzyme so my ob inhibitors are saline and

As well as recycling and these drugs they are given in combination with levodopa plus carbidopa and basically if you take these two drugs that is saline and rossellini they’re irreversible and selective inhibitors of mano-a-mano oxidase b now this solution andressa hélène whenever they are given in normal doses they will inhibit only mono or my neurons this b

But whenever you give these runs at higher doses they will also inhibit the mano-a-mano oxidase enzyme and that will lead to hypertensive crisis which is called cheese reaction with tyramine containing food substances and it will also lead to serotonin syndrome with tricyclic antidepressants and in between these two remember wrestling is more potent compared to

That of saline and these drugs they are found to decrease the disease progression in patients with the parkinsonism

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Drugs inhibiting metabolism of Dopamine – Parkinson's Disease ( Part 5 ) – CNS Pharmacology By Dr.G Bhanu Prakash Animated Medical Videos