module 5a Flashcards
Stimulation of alpha andrenergic receptors on smooth muscles.
Vasoconstriction of blood vessels
Relaxation of GI smooth muscles( decreased mobility)
Constriction of bladder sphincter
Male ejaculation
Contraction of pupillary muscles of eye( dial action)
Stimulation of B1 andrenergic receptors on Myocardium, AV node, SA node results in cardiac stimulation.
Increase force of contractiin( pos. inoteopic effect)
Increase HR ( pos. chromite optic effect)
Increased conduction through the AV node ( pos. dromotropic effect)
Dopaminergic receptors
Causes dilation of the following blood vessels, resulting in increased blood flow Renal Mesenreric Coronary Cerebral
Bronchodilation Others: Uterine relaxation Glycogenolysis in the liver Increase renin secretion in kidneys Relaxation of GI smooth muscle
Stimulation of B2 andrenergic receptors on airways
Bronchodilators: drugs that stimulate B2 receptors of bronchial smooth muscle.
TX of asthma & bronchitis.
Reduction of intra ocular pressure & dilation of pupils: tx of open-angle glaucoma
Alpha- andrenergic receptors
Indications:
Temporary relief of conjunctival congestion.
Alpha andrenergic receptors
Indications:
TX of nasal congestion
Intra nasal (tropical) application causes constriction of dilated arteriolars & reduction of nasal blood flow, thus decreasing congestion
A1 receptor
Indications:
Used to support the heart during cardiac failure or shock, various alpha & beta receptor agonists
Vasoactive Sympathomimetics
(Pressors, Inotropes)
also called cardioselectiv sympathomimetics
dobutamine (Dobutrex)
synthetic catecholamines
(D) Beta 1 adrenergic; a pos. inotropy ( increase CO by increase contractability, increases SV) used esp. for HF. administered IV.
dopamine (Intropin)
(C) Beta 1 adrenergic; dosage related alpha 1 & beta1 receptors(low-dialation of blood vessels in brain, heart, kidneys & mesentery* high-pos inotropic* higher-alpha vasoconstriction) Contraindicated in pts with pheochromocytoma( tumor on adrenal gland that secretes catecholamine. administered IV
epinephrine (Adrenalin)
(C) alpha & beta adrenergic (nonselective) low dose B1& B2, ( cardiac, anaphylactic shock, asthma) high-alpha-vasoconstriction elevates BP administrated sub q & IV
fenoldopam (Corlopam)
(C) Dopamine 1 (D1)agonist(peripheral dopamine) produce vasodilation lower BP.Effective on sodium nitroprusside for short term tx of severe HTN. administered IV
midodrine ( ProAmatine)
(C) alpha1; prodrug converted by liver to desglymidodrine, causes constriction of blood vessels peripherally. TX orthostatic hypotension. administered PO 2-3X day
norepinephrine (Levophed)
(C) alpha & beta-mostly alpha-vasoconstriction also b1(only) It is directly metabolized to dopamine & primarily used tx of hypotension & shock. administered IV (PO)
phenylephrine (Neo-Synephrine)
(C) almost exculsive alpha. short term tx to raise BP in pt in shock, to control some dysrhythmias(supraventricular tachycardias) & produce vasoconstriction i regional anesthesia. Used topically as ophthalmic drug & nasal decongestant. administered sub q & IV
Vasoactive Sympathomimetics
Pressors, Inotopes
dobutamine dopamine
ephedrine epinephrine
fenoldopam phenylephrine
methoxamine noepinephrine
Alpha Adrenergic adverse Effects
CNS:
HA, restlessness, excitement, inswomnia, euphoria
Cardiovascular:
Palpitations(dysrhythmias), tachycardia, vasoconstriction, HTN
Other:
Anorexia, dry mouth, nausea, vomiting
Beta Adrenergic adverse Effects
CNS:
Mild tremors, HA, nervousness, dizziness
Cardiovascular:
Increased HR, palpitations(dysrhythmias),
Other:
Sweating, nausea, vomiting, muscle cramps
Adrenergic Blockers
bind to adrenergic ( alpha & beta) receptors but inhibit or block stimulation of the sympathetic nervous system
Have opposite effect of adrenergic drug
Drug effects & Indications:
Alpha-Blockers
Cause both arterial & venous dilation
reducing peripheral vascular resistance & BP
Used to tx HTN
Effect on receptors on prostate gland & bladder decreases resistance to urinary outflow, reducing urinary obstruction
A drug that quickly reverses the potent vasoconstritive effects of extravasted vaopressors such as norepinephrine or eprinephrine
Restores blood flow & prevents tissue necrossis
phentolamine (Regitine)
phenoxybenzamine HCL (Dibenzyline)
phentolamine (Regitine)
prazosin (Minipress)
tolazoline(Priscoline)
Common alpha blockers
Drug effects & Indications:
Beta-Blockers
Block stimulation of B receptors
Compete with norepinephrine & epinephrine
Selective & nonselective B blockers
Alpha blocker adverse effects
CNS:
dizziness, HA, drowsiness, anxiety, depression, vertigo, weakness, numbness, fatigue
Cardiovascular:
palpatations(dysrhythmias), orthostatic hypotension, tachycardia, edema,chest pain
Alpha blocker adverse effects
GI:
nausea, vomiting, diarrhea, constipation, abdominal pain
Other:
incontinence, nosebleed, tinnitus, dry mouth pharyngitis, rhinitis
Indications for Beta blockers
Angina;decreases demand for myocardial O2
Cardioprotective:inhibits stimulation from circulating catecholamines
Dyusrhythmias:Class II antidysrhythmic
Migraine:lipophilicity allows entry into CNS
Antihypertensive
HF
Glaucoma(topical use)
Beta blocker adverse effects
Blood:
agranulocytosis, thrombocytopenia
CNS:
dizziness, depression, lethargy, hallucinations
Cardiovascular:
AVblock, bradycardia, HF, peripheral vascular insufficiency
Beta blocker adverse effects
GI:
nausea, dry mouth, vomiting diarrhea, cramps, ischemic colitis
Other:
impotence, rash alopecia, bronchospasms
Beta Blockers
acebutolol(Sectral) atenolol(Tenomin)
carvedilol(Coreg) esmolol(Brevibioc)
labeltalol(Trandate) sotalol(Betapace)
metoprolol(Lopressor) propranolol(Inderal)
-note end in lol-
Cholinergic Drugs:
Mimic the effects of the PSNS neurotransmitter: acetylcholine
Cholinergic Receptors
Two types, determined by location action once stimulated Nicotinic receptors Muscarniic receptors
Niccotinic Receptors
Located in the ganglia of both the PSNS & SNS.
Named nicotinic because they can be stimulated by the alkaloid nicotine.
Muscarinic Receptors
Located postsynaptically in effector organs of PSNS
Smooth muscle
Cardiac muscle
Glands
Namediscarinic because they can be stimulated by the alkaloid muscadine
MOA of muscarinic receptor
Direct: bind to cholinergic receptors activating them
Indirect:inhibit the enzyme acetylcholinesterase, which breaks down Ach
Results in more Ach available
Indirect -acting (cholinesterase inhibitors
Reversible-bind to cholinesterase for a period of minutes to hrs
Irreversible-bind to cholinesterase &form a permanent covalent bond
Body must make new cholinesterase
Cholinergic Drug Effects
"SLUDGE" Salivation Lacrimation Urination Diarrhea/defection GI cramps Emesis
Drug effects
@ recommend doses the cholinergic s primarily affect the muscarinic receptors
@ high doses, cholinergic s stimulate the nicotinic receptors
MANY undesirable effects are due to stimulation of nicotinic receptors
Indications Direct-acting drug
Direct acting drugs Reduce intraocular pressure Useful for glauca& intraocular surgery Acetylcholine Carbachol Pilocarpine Topical appltn bcus of poor oral absorption
Indications Direct-acting drug
Direct-acting drug—bethanechol
Increases tone and motility of bladder and GI tract
Relaxes sphincters in bladder and GI tract allowing tract, them to empty
Helpful for postsurgical atony of the bladder
and GI tract
Indications Direct-acting drug
Direct-acting drug—cevimeline (Evoxac)
Used to treat xerostomia (dry mouth) resulting from Sjögren’s syndrome
Indications indirect acting anticholinesterase drug
Indirect-acting drugs
Cause skeletal muscle contractions
Used for diagnosis and treatment of
myasthenia gravis
Used to reverse neuromuscular blocking drugs
Used to reverse anticholinergic poisoning (antidote)
Examples: physostigmine, pyridostigmine
Indications indirect acting anticholinesterase drug
Indirect-acting anticholinesterase drugs Used for treatment of mild to moderate Alzheimer’s disease • donepezil (Aricept) • tacrine (Cognex) • galantamine (Razadyne) • rivastigmine (Exelon)
Indications indirect acting anticholinesterase drug
memantine (Namenda)
Not a cholinergic drug
Also used in the treatment of Alzheimer’s disease
Adverse Effects
Adverse effects as a result of over stimulation of PSNS
CNS: HA, dizziness, convulsions
Cardio: Bradycardia, hypotension, conduction, abnormalities(AV block& cardiac arrest)
GI: cramps, increased secretions, nausea, vomiting
Respiratory: increased secretions, bronchospasms
Other: lacrimation, sweating, salavation, miosis(constiction)
Cholinergic-Blocking Drugs
MOA
Competitive antagonists
Compete with Ach
Block Ach at the muscarinic receptors
in the PSNS
As a result, Ach is unable to bind to the
receptor site and cause a cholinergic effect
Once these drugs bind to receptors, they
inhibit nerve transmission at these receptors
Chemical Class
Natural Synthetic/Semisynthetic
atropine benztropine clidinium
belladonna dicyclomine glycopyrrolate
hyoscyamine homatropine ipratropium
scopolamine isopropamide methscopolamine
oxybutynin propantheline
tolterodine trihexyphenidyl
Drug Effects
Cardiovascular Small doses: decrease heart rate Large doses: increase heart rate CNS Small doses: decrease muscle rigidity and tremors Large doses: drowsiness, disorientation, hallucinations
Drug Effects
Eye Dilated pupils (mydriasis) Decreased accommodation due to paralysis of ciliary muscles (cycloplegia) Gastrointestinal Relax smooth muscle tone of GI tract Decrease intestinal and gastric secretions Decrease motility and peristalsis
Drug Effects
Genitourinary
Relaxed detrusor muscle
Increased constriction of internal sphincter
Result: urinary retention
Glandular
Decreased bronchial secretions, salivation,
sweating
Drug Effects
Respiratory
Decreased bronchial secretions
Dilated bronchial airways
Indications for CNS
Decreased muscle rigidity and muscle
tremors
Parkinson’s disease
Drug-induced extrapyramidal reactions
Indications for Cardiovascular
Affect the heart’s conduction system Low doses: slow the heart rate High doses: block inhibitory vagal effects on the SA and AV node pacemaker cells Result: increased heart rate
Indications for Cardiovascular
Atropine Used primarily for cardiovascular disorders Diagnosis of sinus node dysfunction Symptomatic second-degree heart block Severe sinus bradycardia
Indications for Respiratory
Blocking the cholinergic stimulation of the PSNS allows unopposed action of the SNS Results Decreased secretions from nose, mouth, pharynx, bronchi Relaxed smooth muscles in bronchi and bronchioles Decreased airway resistance Bronchodilation
Indications for Respiratory
Respiratory drugs are used to treat: Exercise-induced bronchospasms Chronic bronchitis Asthma Chronic obstructive pulmonary disease
Indications for GI
PSNS controls gastric secretions and smooth muscles that produce gastric motility Blockade of PSNS results in: Decreased secretions Relaxation of smooth muscle Decreased GI motility and peristalsis
Indications for GI
Gastrointestinal drugs are used to treat:
Irritable bowel disease
GI hypersecretory states
Indications: Genitourinary
Reflex neurogenic bladder Incontinence Acute pancreatitis (reduces gastric and pancreatic secretions) Preoperatively: to reduce salivary secretions
Adverse Effects
CNS:restlessness, irritability, disorientation, hallucinations, delium
Cardio: Increased HR, dysrhythmias
Eye: dilated pupils, decreased visual accommodation, increasedx intraocular pressure
Adverse Effects
GI: decreased salivation decreased gastric secretions, decreased mobility
Genitourinary: urinary retention
Glandular: decreased sweating
Respiratory: decreased bronchial secretions
Alzheimer’s disease
Irreversible loss of neurons plaques & tangles in the cortex & hippocampus.
Parkinson’s disease
Lack of neurotransmitter dopamine.
Glycogenolysis
Conversion of glycogen to glucose in the liver.
Albuterol
Bronchodilator
Ephedrine
Brinchodilator
Epinephrine
Bronchodilators
Formoterol
Bronchodilator
Levanuterol
Bronchodilators
Metaproterenol
Bronchodilator
Pirbuterol
Bronchodilators
Salmeterol
Bronchodilator
What is terbutaline normal used for and it’s special use?
It is a bronchodilator & is used to stop premature labor( causes relaxation of uterine smooth muscle
Epinephrine
Used to treat open-angle glaucoma( reduces t pressure (dilation).
Alpha andrenergic
Dipivefrin
Used to tx open-angle glaucoma( reduces intraocular pressure( dilation)
Alpha adrenergic
Epinephrine
Temp relief of conjunctival contest ion. Alpha andrenergic
Naphazoline
Tmp relief of conjunctival congestion. Alpha andrenergic
Phenylephrine
Tmp relief of conjunctival congestion. Alpha adrenerg
Tetrahydrozoline
Tmp relief of conjunctival congestion. Alpha adrenergic
