Amlodipine is a calcium channel blocker that belongs to dihydropyridine category. This drug contains amino group and chlorine group in the structure from which name can be derived. It blocks voltage gated L-type calcium channels at both cardiac and vascular smooth muscle with more pronounced effect on the later.
Hi everyone today in this video let us discuss about amlodipine how this drug acts what is the mechanism side effects dragon transitions and precautions of amlodipine what is this amlodipine amrodipine is one of the calcium channel blocker which is commonly known as ccb but this drug can be differentiated from the other calcium channel blockers with few structural
Features we can split the name into three parts the prefix am indicates this drug is having some amino group attached with ethoxy so amino ethoxy group is present in the amlodipine and the infix low indicates this drug is having a chloro group because we have the groups like chlorine and nitro group can influence the potency of the drug so this duck is having a
Chloro group in the structure and finally the suffix dip in indicates this drug is a dihydropyridine so from the dihydropyridine we can take the suffix dip in this is the structure of dihydropyridine which is having the saturation at first and fourth portions so amlodipine is a dihydropyridine with amino ethoxy moiety and chloro group within the structure now
If we see the chemical nature of amlodipine this is the structure of amlodipine and here we can find the heterocyclic ring system that is the pyridine so let us give the numbering from the nitrogen this is one two three four five and six now this ring is saturated at first and fourth position so commonly it is known as one four dihydropyridine and we can also
Find the ester groups at third and fifth position so the suffix of the name is nothing but pyridine three five dicarboxylate it’s a diester but here the esters are not formed by the same groups at the third portion ethyl group is forming the ester but at the fifth portion methyl group is forming the ester so we can put the prefix three tile phi methyl then
What are the other attachments so second portion is simply attached with a methyl group which is further attached with a different group so all we have seen it is having amino ethoxy group so at the second position this methyl group is further attached with the amino ethoxy group so we can write this as 2-2 amino ethoxy methyl then what is the group at the
Fourth position fourth position is having a phenyl ring which is attached with a chloro group at the ortho portion so we can write this as 4-2-chlorophenyl and this pyridine ring system is saturated at first and fourth position so one for dihydro and sixth position is having the methyl group so six methyl so that completes the name of the amlodipine now let
Us see how amlodipine name is derived from the chemical name so from this amino ethoxy we are going to take the am and from this chloro we are going to take the lo and from this dihedral we are going to take di and from the pyridine we are going to take the p and i n e so that is the amlodipine so amlodipine is a calcium channel blocker which is having an amino
Ethoxy group and chlorine group along with a dihydropyradine ring system now let us see how this drug acts amrotipin is one of the calcium channel blocker it can block the l-type calcium channels present on the cardiac muscle as well as it can also block the l-type calcium channels present on the vascular smooth muscle and particularly dihydropyridines are more
Selective towards the vascular muscle so amrotipine shows the more affinity towards the type calcium channels present on the vascular smooth muscle compared with the cardiac muscle but still this drug can show action on both cardiac muscle as well as vascular smooth muscle now let us see action on cardiac muscle within the cardiac muscle different types of ion
Channels are present one of the important ion channels are the sodium channels so through this voltage-gated sodium channel sodium can enter into the membrane which produce the depolarization of the cardiac muscle so when the sodium ions are entered the action potential is going to be propagated into the t tubules and when this action potential reaches to the
T tubules calcium channels are going to be activated so these calcium channels are the l-type calcium channels and cancer within the cardiac muscle is also controlled by the store-operated calcium channels which are present on the sarcoplasmic reticulum now when the action potential reaches to the tubules the calcium ions can enter through these l-type calcium
Channels and then they can activate the store-operated calcium channels these store-operated calcium channels are nothing but the rhinode receptors which when they are activated they can release the a large amount of the calcium into the cytoplasm in this way when the l-type calcium channels are activated it results in the increased intracellular calcium levels
Within the cardiac muscle which result in the contraction of the cardiac muscle so this is a normal contractile mechanism within the cardiac muscle now the amlodipine which is administered can be protonated within the plasma so within this protonated form it can act on the l-type calcium channels amlodipine can bind to one of the binding site this is called as
Dihydropyridine binding site now this drug is going to bind to this dihydropyridine binding site such that it is going to inhibit the l-type calcium channel activity so when these calcium channels are inactivated calcium cannot enter and it cannot produce the contraction of the cardiac muscle in this way amlodipine can reduce the rate of contraction as well as
Force of contraction of the heart now that is the action of the amlodipine on vascular smooth muscle so vascular smooth muscle is again equipped with the l-type calcium channels now calcium can enter through these l-type calcium channels into the cytoplasm but here the contractile mechanism is somewhat different this calcium can bind with the calmodulin so
Calcium can bind with scalp modulin so that it forms a calcium karma gillian complex this will activate the myosin light chain kinases these myosin light chain kinase are going to be activated by this calcium calmodulin complex and this mlck is required for phosphorylation of the mlc myosin light chains now mlc are the myosin light chains which are phosphorylated
By mlck says that mlc is gonna do mlc phosphate the phosphorylated form of the myosin light chains within this phosphorylated form they can combine with the actin filament such that they are going to form a actomyosin complex when this actin and myosin are going to form an ectomyosin complex it results in the sliding on each other producing the contraction of
The vascular smooth muscle in this way l-type calcium channels are playing an important role in contraction of the vascular smooth muscle now again these l-type calcium channels are having dihydropyridine binding site on which the amyloid pin can bind ambrodipine is going to interact with this dihedrin binding site such that it is going to inhibit the activity
Of the l-type calcium channels so just like the cardiac muscle amlodipine again inhibits l-type calcium channel activity thereby inhibits the contraction of the vascular smooth muscle so these are the two important mechanisms of the amyloid pin it can block the l-type calcium channel such that it can inhibit the contraction of the cardiac muscle as well as
The vascular smooth muscle what are the side effects the important side effect is the headache as well as edema these two side effects are mainly related with the vasodilation as well as increased capillary permeability so these two side effects are more important many of the patients the headache is because of cerebral vasodilation and edema is because of the
Accumulation of the body fluids apart from these two side effects amlodipine can also produce few of the other side effects like fatigue nausea abdominal pain and it can also produce a some knowledge and fear the vasodilatory symptoms like dizziness flushing can also be observed amoled pin can also produce a palpitations because of the reflex mechanism what
Are the precautions already we have seen that amlodipine can act on the cardiac muscle such that it reduce the force of contraction when the force of contraction is going to be reduced it reduce the cardiac output so this is somewhat important in the patients who are having the cardiovascular disorders so amlodipine can aggravate the anginal attack as well as
The myocardial infarction particularly these conditions are elevated in the patients who are having an obstruction in the cardiac conduction system so ambrodipine should be carefully given in the patients who are having the anger and myocardial infarction along with the abstraction the cardiac conduction system second precaution is amlodipine is connected to
Metabolites within the liver this drug is long acting with half-life of 56 hours but in the patients who are having a severe hepatic failure this metabolism may be impaired which may result in the increased half-life of amlodipine so in such patients there may be an accumulation of the amlodipine levels within the plasma which should be carefully monitored third
Important precaution is amlodipine is going to produce a vasodilation thereby produce the hypotension even it is not producing the acute hypotension but still any symptoms of hypotension like flushing dizziness and headache should be carefully monitored in the drug interactions so all we have seen amlodipine is metabolized within the liver into the metabolites
And one of the important enzyme is the cyp3f4 so if you have the drugs like uh ketokinazole hydra etrakanazole and return aware these are the strong cyp3a4 inhibitors which can inhibit the metabolism of the amlodipine resulting in the increased levels of this drag whenever strong cyp 3 for anybody the plasma level should be carefully monitored clinical uses
Since this drug is a vasodilator it is particularly used in the treatment of hypertension it can be given alone or in combination in the treatment of hypertension similarly this drug can also act on the heart and it can also reduce afterload so this drug is useful in the treatment of vasospastic angina as well as chronic stable angina and sometimes amro dipping
Can also be given the coronary artery disease in the patients who are not associated with the heart failure because in the heart failure cardiac output is already reduced amlodipine is reducing the force of contraction which further reduces the cardiac output so in the patients who are having heart failure particularly in the patients who are having the less
Ejection fraction in such people amlodipine should not be used how it is given ambrodipine is available as a tablet in the different doses like 2.5 mg 5 mg and 10 mg the initial dose is started at 5 mg per day and the maximum dose that can be admitted is 10 mg but in the patients who are having severe hepatic impairment the dose may be reduced so initial dose
May be reduced to 2.5 mg so that’s about the amlodipine amlodipine is a calcium channel blocker with an amino ethoxy group as well as chloro group within the structure this drug can act on both cardiac muscle as well as vascular smooth muscle with more affinity towards the vascular smooth muscle and since this drug acts as vasodilator this duct can be used in the
Treatment of hypertension as well as vasospastic and chronic stable angina and this drug can also be given in fear of the coronary artery disease in the patients who are not associated with the heart failure this drug is protonated within the plasma and it can block the l-type calcium channels by binding to that dihydropyridine binding site headache and edema
Are the two important side effects that can be produced by this amlodipine so that’s about this drag hope you have enjoyed this video if you like this video please subscribe to our channel share this video with your friends post your comments in the comment box thank you for watching this video
Transcribed from video
Amlodipine – Mechanism, side effects, interactions and uses By egpat