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82 terms

Autonomic nervous system receptors (adrenergic and cholinergic drugs)

Pharmacology lecture 3
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Alpha 1 receptor sympathetic effects
Contraction of smooth muscle, exocrine gland secretion, and neuronal excitation
Alpha 2 receptor sympathetic effects
Inhibition of Nor adrenaline release Decreased secretion of aqueous humour and insulin
Beta 1 receptor sympathetic effects
Mainly increased HR and contraction. Increased renin secretion
Beta 2 receptor sympathetic effects
Glycogenolysis, smooth muscle relaxation Uptake of potassium into skeletal muscle
Beta 3 receptor sympathetic effects
Lipolysis in adipose tissue
Muscarinic M1 receptor parasympathetic effects
Modulation of neurotransmission (neural)
Muscarinic M2 receptor parasympathetic effects
Slowing of HR and contraction (maintains homeostasis in conjunction with Beta 1)
Muscarinic 3 receptor parasympathetic effects
Contraction of smooth muscles and stimulation of glandular secretions (saliva) and Vascular smooth muscle dilation = vasodilation
Nicotinic Nm receptor parasympathetic effects
Contraction of muscles
Nicotinic Nn receptor parasympathetic effects
Excitation of postganglionic neurons
Effects of Nor adrenaline on Beta 1
>HR
>contractility (<cardiac efficiency)
> risk of arrhythmia
Effects of Nor adrenaline on Alpha 1
Vasoconstriction of blood vessels
Effects of Nor adrenaline on Alpha 2
Vasoconstriction of blood vessels
< neurotransmitter release
Is adrenaline an adrenocepter agonist or antagonist
direct acting adrenoceptor agonist
Effects of Nor adrenaline on Beta 2
Vasodilation
Bronchodilation
Mobilize energy stores
Is dobutamine an adrenoceptor agonist or antagonist
direct acting adrenoceptor agonist
What is the mode of action of Dobutamine
Stimulates Beta 1 and Beta 2 receptors
What is the mode of action of Adrenaline
Stimulates Alpha 1 & 2 and Beta 1 & 2 receptors
What is the pharmacological effect of Dobutamine
> in HR and > in contractility (Beta 1)
Vasodilation (Beta 2)
What is the pharmacological effect of Adrenaline
Vasoconstriction > BP (α1),
cardiac stimulation, >HR and force of contraction (β1),
bronchodilation (β2)
Side effects of dobutamine
Arrhythmias
Side effects of adrenaline
Hypertension and arrhythmias
Are salbutamol and salmeterol adrenoceptor agonists or antagonists
direct acting adrenoceptor agonists
What is the mode of action of salbutamol and salmeterol
bind to beta 2 receptors
What is the pharmacological effect of salbutamol and salmeterol
Bronchodilation due to smooth muscle relaxation
Side effects of salbutamol and salmeterol
tachycardia and arrythmias
What is phenylephrine agonist or antagonist
Direct acting adrenoceptor agonist
What is phenylephrine mode of action
Binds to alpha 1 receptors
What is the pharmacological effect of phenylephrine
vasoconstriction leading to > in BP
side effects of phenylephrine
bradycardia
hypertension
What is amphetamine direct or indirect
Indirect acting adrenoceptor agonist
What is the mode of action of an amphetamine
Causes an increase in the release of noradrenaline from the storage vesicles
Side effects of amphetamines
Hypertension
tachycardia
dependance
what is the pharmacological effect of amphetamines
CNS stimulant increases brain activity
what is cocaine direct or indirect
Indirect acting adrenoceptor agonist
What is the mode of action of cocaine
Inhibits uptake of noradrenalin
Side effects of cocaine
Hypertension
cardiac damage
necrosis of nasal mucosa
what is the pharmacological effect of cocaine
vasoconstriction due to increase in noradrenalin levels
What is pseudoephedrine
A mixed acting adrenoceptor agonist
what is psuedoephedrine mode of action
Causes release of nor adrenaline from storage vesicles in the presynaptic neuron.
Pharmacological effect of pseudoephedrine
Vasoconstriction due to increased NA being availablet o bind to the alpha 1 receptors of blood vessels
What is ephedrine
a mixed acting adrenoreceptor agonist
what is ephedrines mode of action
Causes more nor adrenaline to be released from the storage vesicles
Pharmacological effects of ephedrines
Vasoconstriction due to increased NA being available to bind to the alpha 1 receptors.
Side effects of ephedrine and pseudoephedrine
hypertension
tachycardia
insomnia and dependance
What is prazosin
adrenergic antagonist (alpha blocker)
What is the mode of action of prazosin
alpha 1 receptor blocker
pharmacological effects of prazosin
decreased vascular resistance due to vasodilation
drop in BP relax bladder and prostate
side effects of prazosin
orthostatic hypotension
Nasal congestion
urinary urgency
what is phentolamine
adrenergic antagonist ( alpha blocker)
what is the mode of action of phentolamine
blocks alpha 1 and 2 receptors
what are the pharmacological effects of phentolamine
decreased vascular resistance due to vasodilation and resultant drop in BP
what are the side effects of phentolamine
orthostatic hypotension
tachycardia
nasal congestion
What is atenolol
adrenergic antagonist (beta blocker)
What is the mode of action of atenolol
blocks the beta 1 receptor
what are the pharmacological effects of atenolol
reduces cardiac rate and output
reduces Av node conduction
reduces O2 demand
reduces BP
What are the side effects of atenolol
cardiac failure
hypoglycemia
bronchoconstriction
What is propanolol
An adrenergic antagonist (beta blocker)
what is the mode of action of propanolol
blocks beta 1 and 2 receptors
what is the pharmacological effect of propanolol
reduces cardiac rate and output
reduces AV node conduction
reduces O2 demand
reduces BP
what are the side effects of propanolol
cardiac failure
bronchoconstriction
hypoglycemia
what is carvedilol
an adrenergic atagonist (alpha and beta blocker)
what is the mode of action of carvedilol
blocks beta 1 and 2 receptors and alpha 1 receptors
what is the pharmacological effect of carvedilol
In pts with hypertension vasodilation drop in HR and BP
in Pts with heart failure increase in cardiac output
side effects of carvedilol
cardiac failure
hypoglycemia
bronchoconstriction
renal failure
What are the side effects of muscarinic stimulation
diarrhoea, urination, miosis, bronchoconstriction, emesis, lacrimation and salivation.
What is nicotine
a direct acting cholinergic agonist
What receptor does nicotine act on
Nicotinic receptor
What can nicotine be used for
Smoking cessation
what is pilocarpine
A direct acting cholinergic agonist
what receptor does pilocarpine act on
M3 and nicotinic receptors
what can pilocarpine be used for
xerostomia treatment, glaucoma due to reduction of intraocular pressure
what are the 2 types of nicotinic antagonists
Non de-polarising (blocks Ach receptors: Ach can't bind so no influx of Na and no depolarisation)
Depolarising (agonists at Ach receptors)
what is an example of a non-depolarising antagonist
tubocurarine analogues
what is the use of a non-depolarising antagonist
neuromuscular blockers muscle relaxation for surgical anaesthesia Can be used for fixing mandibular fractures
What is an example of a depolarising antagonist
suxamethonium
What can suxamethonium be used for
brief procedures such as endoscopy and colonoscopy
What was the first reversible muscarinic antagonist (anticholinergic drug)
atropine
How does atropine work
blocks the effects of the vagus nerve on the heart therefore increases heart rate
What are 3 other anticholinergics
pirenzepine (M1 inhibition of gastric secretion)
hyoscine (anti emetic and antispasmodic)
ipratropium (bronchodilation)
What are the side effects of atropine OD
Dry mouth, decreased sweating, increased HR,blurred vision, tachycardia, palpitations, urinary retention, restlesness, fatigue, rapid weak pulse, ataxia, hallucinations, delerium and coma
What is most significant side effect for dentistry of anticholinergics
xerostomia