This document summarizes the actions and clinical applications of major adrenergic drugs, including:
1) Sympathomimetics like amphetamine and ephedrine act indirectly by releasing catecholamines from neurons, while direct-acting drugs interact directly with adrenoceptors.
2) Sympatholytics include direct-acting antagonists that block adrenoceptors and indirect-acting drugs that interfere with norepinephrine release or synthesis.
3) Adrenergic drugs have applications for conditions like hypotension, shock, asthma, and hypertension. Common side effects include hypotension, tachycardia, and sedation.
These are the drugs which antagonize the receptor action of adrenaline and related drugs.
These drugs act by blocking a and/or ß-adrenergic receptors.
α-blockers
PRAZOSIN is a competitive antagonist effective in the management of hypertension. Similar drugs with longer half-lives (e.g. doxazosin, terazosin).
β-blockers
Heart - Decrease heart rate, force of contraction and cardiac output.
Blood Pressure - Decrease in blood pressure (blockage).
Respiratory System – bronchoconstriction.
Eye – Beta-blocking agents reduce intraocular pressure, especially in glaucoma. The mechanism usually reported is decreased aqueous humor production.
Metabolic - Increase LDL and decrease HDL.
Uterus - Relaxation of uterus.
Local anaesthetic - Propranolol has some local anaesthetic action
These are the drugs which antagonize the receptor action of adrenaline and related drugs.
These drugs act by blocking a and/or ß-adrenergic receptors.
α-blockers
PRAZOSIN is a competitive antagonist effective in the management of hypertension. Similar drugs with longer half-lives (e.g. doxazosin, terazosin).
β-blockers
Heart - Decrease heart rate, force of contraction and cardiac output.
Blood Pressure - Decrease in blood pressure (blockage).
Respiratory System – bronchoconstriction.
Eye – Beta-blocking agents reduce intraocular pressure, especially in glaucoma. The mechanism usually reported is decreased aqueous humor production.
Metabolic - Increase LDL and decrease HDL.
Uterus - Relaxation of uterus.
Local anaesthetic - Propranolol has some local anaesthetic action
This presentation contains drugs which blocks the adrenergic system e.g receptor blockers like alpha and beta receptor antagonists, adrenergic neuron blocking agents in details.various animated pictures are also included to make the presentation interesting as well as i have used various diagrams and tables to have better understanding of the topic. Thank you.
This presentation contains drugs which blocks the adrenergic system e.g receptor blockers like alpha and beta receptor antagonists, adrenergic neuron blocking agents in details.various animated pictures are also included to make the presentation interesting as well as i have used various diagrams and tables to have better understanding of the topic. Thank you.
This presentation contains a brief introduction of Adrenergic and cholinergic systems and their function in our body.
And a brief description of some adrenergic and cholinergic agents along with their mechanism of action along with their respective Structures.
this lecture talks about adrinergic drugs used in main body
its stimulates sympathetic system cause a case called "fight and flight "
it talks about qat And how relationship between the structure and action
A disorder of the central nervous system that affects movement, often including tremors.
Nerve cell damage in the brain causes dopamine levels to drop, leading to the symptoms of Parkinson's.
Parkinson's often starts with a tremor in one hand. Other symptoms are slow movement, stiffness and loss of balance.
Treatment consists of medications to increase dopamine.
Sympatholytics or Adrenergic AntagonistsAhmad Naeem
Sympatholytics or Adrenergic Antagonists (Introduction, Classification, Alpha Blockers, Beta Blockers Generations, Respirine)
These are drugs which antagonize the receptor action of adrenaline and related drugs.
Mechanism of Action
The adrenergic antagonists (also called adrenergic
blockers or sympatholytics) bind to adrenoceptors but
don’t trigger the usual receptor-mediated intracellular effects.
These drugs act by either reversibly or irreversibly
attaching to the adrenoceptors, thus preventing
activation by endogenous catecholamine's.
Numerous adrenergic antagonists have important
roles in clinical medicine, primarily to treat diseases associated with the cardiovascular system.
α-Adrenergic Blocking Agents
These drugs inhibit adrenergic responses mediated through the α adrenergic receptors without affecting those mediated through β receptors.
Mechanism of action
Drugs that block α adrenoceptors profoundly affect blood pressure. Blockade of these receptors reduces the sympathetic tone of the blood vessels, resulting in decreased peripheral vascular resistance. This induces a reflex tachycardia resulting from the lowered blood pressure.
Non-Selective α adrenergic antagonists
They cause vasodilation by blocking both alpha-1 and alpha-2 receptors. The blockage of alpha-2 receptors will increase the NE release, which will reduce the force of the vasodilation induced by blockade of the alpha-1 receptors. These are useful for patients with pheochromocytoma.
Selective α1 adrenergic antagonists
They cause vasodilation by preventing NE from activating the alpha-1 receptor, resulting in a lowering of the blood pressure, allowing alpha-1 blockers to be used for hypertension. Alpha-1 blockers also cause relaxation of smooth muscle in the prostate, can be useful for the management of benign prostatic hyperplasia (BPH).
Selective α2 adrenergic antagonists
They inhibit negative feedback of NE, stimulating the sympathetic system.
β-Adrenergic Blocking Agents
Mechanism of Action:
These agents blocks the action of substances, such as adrenaline on nerve cells and causes blood vessels to relax and dilate. This allows blood to flow more easily and lowers blood pressure and the heart rate.
Therapeutic Uses:
Beta blockers are used to prevent, treat or improve symptoms in people who have:
Arrhythmia
Heart failure
Chest pain
Heart attacks
Migraine
Certain types of tremors
Adverse Effects:
Asthma
Heart failure
Hypoglycemia
Bradycardia
1. Adrenergic Drugs II Aims To understand the actions and side effects of major adrenergic drugs, and their clinical applications Read: Chapter 8, Rang and Dale comments to Dr Ian Musgrave (336S) Email: Ian.Musgrave@adelaide.edu.au
8. Close up of Adrenergic terminal NA NA NA NA Tyrosine Dopamine DOPA NA MAO NA NA Metabolites Uptake 1 Vesicular transporter TH DDC D H Vesicular transporter Cocaine
15. Effect of tolazoline and phenoxybenzamine on noradrenergic contraction in cat splenic strips + Tolazoline + Phenoxybenzamine Competitive vs non-competitive antagonism
16.
17.
18. Adrenaline “reversal” adrenaline adrenaline Prazosin Blood Presure Blockade of vasoconstrictor 1 -adrenoceptors reveals vasodilator -adrenoceptors Time Time Blood pressure recordings in anaesthetised dog
24. Adrenaline with and without propranolol adrenaline adrenaline propranolol Blodd Pressure Blockade of vasodilator -adrenoceptors reveals vasoconstrictor -adrenoceptors Time Time
33. Cartoon of adrenergic receptors showing the 7 transmembrane spanning domains G S Family G i/o Family Adenylyl cyclase +ve -ve ATP cAMP -adrenoceptors 2 -adrenoceptors Biological response cAMP dependent protein kinase
34. Structure-activity relationships Looking down on the -adrenoceptor from outside the membrane with adrenaline in the binding site between transmembrane domains 3,5 and 6 (model based on rhodopsin crystal structure) TM3 TM5 TM6
38. Indirect sympatholytics NA NA NA MeNA Tyrosine Dopamine DOPA NA NA NA Uptake 1 Vesicular transporter TH DDC D H Reserpine -ve Guanethidine -ve MethylDOPA -Methyl tyrosine -ve