Week 3 Flashcards
Cholinergic drugs
Parasympathetic nervous sys (PNS) by mimicking or inhibiting acetylcholine (ACH) which is located at the gaglions and PNS terminal nerve endings. Innervates cholinergic receptors in organs, tissues and glands
Cholinergic receptors
Nicotine and muscarinic
Cholinergic Agonist
Stimulate PNS direct (binds direct to cholinergic rreceptors at target tissue level mimicking acetylcholine) or indirectly (inhibit acetylcholinesterase, prolonging action of natural acetylcholine)
Cholinergic antagonist
Inhibit actions of acetylcholine -> inhibits PNS
Atropine, tolterodine tartrate, scopolamine
CNS antagonist
Large doses = drowsiness, disorientation and hallucinations
DV agonists
De HR, slows conduction through AV node, de BP = vasodilation
CV antagonist
Large doses ^ hr
Small doses de hr
Pulmonary agonist
^ bronchial constriction
^ bronchial secretions
Pulmonary system
De bronchial constrictions
De bronchial secretions
Gastrointestinal agonist
^ gastric motility and peristalsis
Relaxes sphincter muscles
GI antagonist
De gastric motility and peristalsis
Genitourinary agonist
Contracts bladder, relaxes bladder’s sphincter
Genitourinary antagonist
Relaxes bladder and ^ constriction of bladder sphincter
Ocular agonist
Constricts pupils
^ ability to accommodate
Ocular antagonist
Dilates pupils (mydriasis) De ability to accommodate
Glandular
^ salivation, perspiration, and tears
Glandular antagonist
de salivation, perspiration and tears
Skeletal muscle agonist
^neuromuscular transmission, maintain muscle strength and tone
Skeletal muscles antagonists
De muscle rigidity and de tremors
Bethanechol
Agonist med
Bethanechol - mechanisms of action
Direct acting agonist (binds to cholinergic receptors), stimulates muscarinic receptors in bladder and GI tract
^ bladder tone, relaxes bladder sphincter
^ GI smooth muscle tone and motility and relaxes GI sphincters
Bethanechol - therapeutic uses
Treats postoperative nonobstructive urinary retention and urinary retention associated with neurogenic gladder
Bethanechol - pharmacokinetics
Poorly absorbed from GI and % bound to plasma protein is unknown. Crosses BBB. Excreted in urging. 1/2 life is unknown. Onset = 30-90 mins (oral) lasts 2 hrs
Pre-admin - bethanechol
Head to toe assessment Med allergies Past med history Current meds Alcohol and drug use Herbal preparation use Patient baseline vitals Urine output (>1500 mL/d)
Contraindications - bethanechol
Asthma Bradycardia COPD Coronary artery disease GI obstruction Hyperthyroidism Hypotension Irritable bowl syndrome Parkinsonism Peptic ulcer disease Seizures Urinary tract obstruction Integrity of GI or bladder wall is unknown
Drug interactions - bethanechol
De given sympathomimentics, anticholinergics, opioids
^ given another cholinergic agonist (direct/indirect)
Use with caution with ganglionic blocking agents = severe hypotension
Adverse rxns of bethanechol
CV = in and de HR, de BP CNS = headache, dizziness and seizures GI. = cramping, diarrhea, ^ gastric acid secretion, ^ oral secretion Respiratory = ^ bronchial secretions, bronchospasms
Lacrimation, sweating, mitosis
Atropine
Antagonist med
Mechanisms of action - atropine
Inhibits action of acetylcholine by occupying muscarinic receptors
Blocks vagus stimulation ^ HR
Paralyzes iris sphincter = pupillary dilation
Therapeutic uses - atropine
De salivation and respiratory secretions preoperatively
^ HR = Bradycardia
Dilate pupils before eye exam
Pharmacokinetics - atropine
Absorbed well when given parentrally and orally. % bound to plasma protein unknown. Excreted by using, crosses BBB and placenta. Onset immediate. 1/2 life is 2-3 hrs and duration is 4 hrs
How drugs work on the ANS
Turn off SNS
Turn off PNS
Drugs altering neurotransmitters
Affect synthesis Prevent storage Influence release Bind to receptor site Prevent normal breakdown or reuptake
Primary neurotransmitters
Norepinephrine and acetylcholine
Norepinephrine
SNS a catecholamine (epinephrine and dopamine are 2 other catecholamines)
Adrenergic receptors - alpha and beta
Acetylcholine
Effects on both SNS and PNS
Cholinergic receptors - nicotinic and muscarinic
Sympathomimetics
Stimulation of sympathetic nervous systems
Adrenergic agonist
TURN ON the SNS
Parasympathomimetics
Stimulation of PNS
Muscarinic agonist or cholinergic
Turn ON the PNS
Sypatholytics
Adrenergic antagonists
Inhibits SNS
Adrenergic blocker
Turn OFF SNS
Parasympatholytics
Inhibit PNS
Anticholinergic
Turn OFF PNS
Agonist
Turn ON
Act like natural chemical
Antagonist
Turn OFF
Block cellular activity
SNS - sympathmimetics
Adrenergic - stimulate Adrenalin
Fight or flight
Receptor subtypes - alpha, beta
Alpha 1 adrenergic
Receptor agonists
Constricts blood vessels, dilate pupils
Rx septic shock, low BP, nasal congestion, ophalmic exam
Alpha 2
Receptor agonists (don’t use a lot)
Inhibit release of norepinephrine
Rx hypertension
Beta 1
Receptor agonist
^ hr, force of contraction
Rx cardiac arrest, heart failure shock
Heart = pump or ^ strength
HEART
Beta 2
LUNGS
Relaxes bronchial smooth muscle
Bronchodilator
Rx asthma
Adrenergic agonist - actions
Cardiac stimulation ^ blood flow to skeletal muscles Peripheral vasoconstriction Bronchodilation Dilation of pupils
Adrenergic agonists - uses
Restore rhythm in cardiac arrest ^ bp in shock Constricting capillaries Dilating bronchioles Ophthalmic procedures Anaphylaxis
Adrenergic agonist - adverse effects
Tachycardia, palpitations Cardiac dysrhythmias Aginal pain Nervousness, tremor Hypertension Hyperglycemia
Adrenergic agonists - contraindications/precautions
Angina
Coronary insufficiency
Hypertension
Cardiac dysrhythmias
Adrenergic agonist - prototype
Epinephrine (Adrenalin)
Acts on alpha and beta receptors
Norepinephrine (levophed)
Acute situations Vasopressin Predominant ALPHA 1 adrenergic effects Potent vasoconstrictor Rx of shock states
Excessive vasoconstriciton - impair cardiac performance, decrease organ and tissue perfusion
)
Antidote for peripheral IV extravasation - phentolamine (regitine) alpha adrenergic blocker
Albuterol (ventolin)
BETA 2
Asthma, COPD
Oral, inhalation, nebulizer
High doses = stimulate beta 1 receptors
Adrenergic antagonists/blockers
Turn OFF SNS
Block effects of adrenergics
Occupy receptor site or inhibition release of transmitter
Beta-blockers most common
Hypertension, cardiac dysrhythmias, angina, migraine
Hypotension, bradycardia, fatigue
C/p - hypotension, asthma, diabetes
Beta blockers (lol)
Metoprolol (lopressor)
Atenolol (tenormin)
Selective beta 1 blockers
Selective blockers are
A jigsaw puzzle
Fit into the correct sites
No selective blockers
Stacks of blocks
Can be places on top of each other with no particular form
Patient education - beta blockers
CV disease
Rise slowly from reclined position
Possible slow heart beat
Avoid alcohol, antihistamines, muscle relaxants, sedatives
Report sexual dysfunction or depression
Do not stop abruptly
Consult before using OTC cold preparations
Alpha blockers
Not as common
Likely to cause: orthostatic hypotension, reflex tachycardia
Terazosin (hytrin)
-benign prostatic hyperplasia, relaxes muscles of bladder and prostate allowing using to flow
Cholinergic agonists and anticholinergics
Affect PNS
Parasympathomimetics
Parasympatholytics
Acetylcholine
Muscarinic receptors - slow hr, stimulate smooth muscle
Nicotinic receptors - neuromuscular junction (excitatory response), increase neuromuscular transmission
Cholinergic agonists
Parasympathomimetics - turn ON
Increased secretions
Direct acting cholinergic agonist
Indirect acting cholinergic agonist - inhibit cholinesterase (break down acetylcholine)
Metoclopramide (reglan)
Direct active cholinergic agonist
Gerd, nausea, gastroparesis
Speeds up gastric emptying
Adverse rxn - tar dive dyskinesia
Varenicline (chantix0
Nicotinic agonist
Prevents binding of nicotine to receptors
Decreased desire to smoke
12 week course, graduated dosing over week 1
Pregnancy category C
Adverse - mental status changes, mood changes, decreased tolerance to alcohol, Stevens-Johnson syndrome
Cholinesterase inhibitor
Blocks the breakdown of acetylcholine
Allow acetylcholine to accumulate at neuromuscular junction
Donepezil (aricept)
Alzheimer’s
Anticholinergics - actions
Drying of secretions
Decreased GI/GU motility
Dilation of pupils
Anticholinergic - uses
Preop Antispasmodic Antidote Bradycardia/heart block Dilation of pupils Prevent/treat bronchospams
Anticholinergic - adverse effect
Blurred vision; h/a
Dry mouth, constipation, urinary retention
Palpitations/tachycardia
Confusion/excitement, esp in elderly
Fever/flushing
Anticholinergic - contraindications/precautions
Asthma, COPD Angle-closure glaucoma GI/GU obstruction Cardiac dysrhythmias Hypertension
Anticholinergic drugs (ine)
Atropine
Tolterodine tartrate (detrol)
Benztorpine (cogentin)
Scopolamine (transdrem scop)
Anticholinergic syndrome toxicity
“Red as a beet, dry as a bone, blind as a bat, mad as a hatter, hot as a hare, and full as a flask”
