Adrenergic Pharmacology Flashcards
What cranial nerves carry signals TO the body
3,7,9(glossopharyngeal),10
Sacral outflow to innervate pelvis
Two main types of adrenergic receptors
Alpha
Beta
What structures ONLY have a sympathetic innervation
Sweat glands, blood vessels
Which structures ONLY have parasympathetic innervation
Bronchial smooth muscle
How does sympathetic pathway effect sweat glands and why is this the case
Causes release of ACh INSTEAD of noradrenaline to stimulate muscarinic receptors
(they are not innervated by parasympathetic pathways)
What are NANC receptors
Found in the enteric nervous system (they are non-adrenergic and non-cholinergic)
What replaces noradrenaline and ACh in the enteric nervous system
- NO and Intestinal peptide (parasympathetic)
2. ATP and neuropeptide Y (sympathetic)
How does muscarine effect muscarinic receptors
Activates M receptors
What type of receptors are M1-5
G protein coupled receptors
Where are M1 receptors found
Brain
Where are M2 receptors found
Heart
Where are M3 found
Glands and smooth muscle
Where are M4/5 found
CNS
What happens when we activated M2 receptors
Slows heart doen
What drug do we prescribe to prevent bradycardia and cardiac arrest
Atropine (blocks M2)
Where is Noradrenaline released vs adrenaline
Noradrenaline is released from sympathetic nerve fibre ends
Adrenaline is released from adrenal glands
What is the precursor for adrenaline and noradrenliane
Dopamine
Does alpha 1 have a higher affinity for Nad or Ad
NAd
What happens after binding to alpha 1
Increases intracellular calcium and Gq signalling
Constricts smooth muscle (vasoconstriction)
What two adrenergic receptors have equal affinity for Nad and Ad
Alpha 1 and Beta 1
What adrenergic receptor had greater affinity for Ad
Beta 2
What adrenergic receptors have a greater affinity for beta 3 an alpha 1 receptors
NAd
Effect of alpha 2 activation
Smooth muscle effects
Effect of beta 1
Increase heart rate
May cause arrhythmia
Define chronotropic
Factors that Change the heart rate
Define inotropic
Factors that affect the strength of heart contraction s
Where are alpha 1 most influential
Skin and abdominal bed
What drug do we prescribe for alpha activation in nasal decongestion
Xylometazoline
What receptors does Clonidine act on
Alpha 2 (agonist)
What does Clonidine do
Lower BP
Role of Doxazosin
Blocks alpha 1 to lower BP (same job as clonidine)
Role of Tamsulosin
Blocks alpha 1A receptors in prostate to treat prostatic hypertrophy
How do we treat asthma
Beta 2 agonists (muscle relaxation)
Side effects of beta agonists
Tachycardia and effects glucose metabolism in the liver:
What adrenergic receptors affect carbohydrate and lipid metabolism
Beta 1 and 3
What receptor do we activate (agonist) to reduce over-active bladders
Beta 3
When is propranolol given and what receptors do these effect
Beta 1 and 2
Slow HR and reduce tremours
Side effect of propranolol
Cause wheeze
When is Atenolol given and what receptors do these effect
Beta-1
Lowers BP by reducing CO and sympathetic outflow activity) - treat arrhythmias
Two drugs with similar effects as Atenolol
Bisoprolol
Metoprolol
4 uses of beta blockers
Angina MI prevention High BP Anxiety Arrhythmias Heart Failure
When is Methyldopa given
Last resort antihypertensive
How does methyldopa work
Blocks Nad synthesis
How do MAOIs effect Nad breakdown
Prevent it (acts as an antidepressant)
If a patient has a cardiac arrest, what would we prescribe them
Atropine for bradycardia
What would we prescribe to patients with well-controlledd COPD with prostatic hypertrophy and bladder instability
COPD - M3 antagonist, B2 agonist
Prostatic hypertrophy - alpha agonist
Bladder instability - B3
What would we prescribe individuals with cardiac disease (angina or fibrillation)
Beta 1 blocker
What would we prescribe parents with pneumonia and septic shock and wheeze
Pneumonia and septic shock - Noradrenaline
Wheeze - Beta agonist
What would we prescribe patients who are penicillin allergic and get anaphylaxis
Adrenaline
How is adrenaline synthesised
Tyrosine -> DOPA -> Dopamine ->Noradrenaline -> Adrenaline
What enzyme converts tyrosine to DOPA
Tyrosine Hydroxylase
What enzyme converts DOPA to dopamine
DOPA decarboxylase
What enzyme converts noradrenaline to adrenaline
Phenyl ethanol amine N-methyltransferase
What enzyme catalyses conversion of dopamine to noradrenaline
DOPAMINE beta-hydroxylase
What enzymes inactivate noradrenaline
MAO and COMT (the equivalent to ACh Esterase)
How do MAO and COMT inactivate noradrenaline
Metabolising it to reduce its stimulant effect
What other hormone are inactivated by MAO and COMT
Adrenaline and Dopamine
Physiology of Alpha-1 adrenceptors
Gq protein bound to alpha 1 and phospholipase C
PI -> DAG and IP3 via phospholipase C
DAG and IP3 cause cascade
Physiology of alpha-2 receptors
Couples with Gi (i inhibit) and inhibit coupled adenyl cyclase
What are beta receptors coupled with
Gs and adenyl cyclase
What does Gs in beta receptors activate
Protein Kinase from cAMP
Adrenergic receptors in Blood vessels
Alpha 1
Adrenergic receptors in heart
Beta 1
Adrenergic receptors in Smooth muscle
Beta 2
What two drugs effect blood vessels and bladder only
Phenylephrine
Oxymetazoline
- vasoconstriction
Why are phenylephrine and oxymetazoline useful as nasal decongestants
Vasoconstriction results in less fluid leakage from vessels
How does amphetamines and cocaine effect nerves
Inhibits noradrenaline transporter on pre-synaptic neurone resulting in build up of catecholamines - CNS overstimulation
How does Mao and COMT inhibition effect the adrenergic junction
Build up of noradrenaline and dopamine
treat parkinson + depression
Name an alpha 2 antagonist
Yohimbine - noradrenaline inhibition does not occur leading to an increase in noradrenaline and other catecholamines
Why should we not use beta blocker sin asthmatics
Most will already be on beta 2 agonists
