Parasympathetic
Acetylcholine (Cholinergic)
Rest and Digest
Sympathetic
Norepinephrine (Adrenergic)
Flight or Fight«_space;survival
Cholinergic Agonist
Parasympathomimetic
Mimics acetylcholine
Used in Glaucoma, GI statsis, Urine Bladder Dysfunction
Reglan (metoclopramide)
Reglan
Sensitizes tissue to effect of acetycholine
Increases gastric emptying (DM statsis)
Facilitates GI intubation
Aid passing of Barium after procedure
Reduces nausea r/t chemo or radiation therapy
Reglan Interactions
Increased effect with:
anticholinesterase- also has cholinergic effects
ganglionic blockers
Decreased effect with:
cholinergic blockers (atropine, scopolamine)
Sympathomimetics (opposite effect)
Anticholinergics
Effects of Parasympathetic System
pupils constrict; increased salivation; bronchial constriction; heart rate decrease; GI tract increased secretions and motility; bladder tone better= voiding
Reglan
Adverse Reactions
Undesired parasympathetic effects
CNS - drowsy, fatigue, agitation
GI - N/D, constipation, dry mouth
Overstimulation can lead to circulatory collapse hypotension, shock, cardiac arrest
Reglan
Nursing Implications
Give po 1 hr ac or 2 hr pc (dec nausea) Check amlyase and lipase levels for elevation Check for urinary retention Check Bowel sounds Atropine is antidote (prn)
Pilocarpine
cholinergic agonist
mimics acetycholine action
binds to receptor sites of smooth muscles
Reduces intraocular pressure
Used in glaucoma and ophalmologic surgery
Pilocarpine
Adverse Reactions
Blurred vision
Lid pain
Rare systemic effects, abd. cramps, increased salivation
Pilocarpin
Nursing Implications
Do not give in acute iritis, corneal abrasion
Caution with asthma, ulcers, Parkinson’s
Teach pt to take gtts at night b/c blurred vision
Anticholinesterase Agents
Prostigmine & Tensilon
Facilitate acetylcholine action by inhibiting its destruction by actylcholinesterase enzyme
Used to Dx and Tx myasthenia gravis
Cholinergic Blocking Agents
Block action of acetylcholine in parasympathetic Nervous System
Refereed to as Belladonna alkaloids
Wide spread effects from actions at many target sites
Atropine
Greatest effect to increase heart rate Drug of choice for sinus bradycardia prevents vagal stimulation (keeps HR up) Decreases secretions, peristalsis Causes urinary retention Bronchial dilation and decreases secretions
Scopolamine
Greatest effect in the CNS 1st excitement then depression
pupillary dilation
decreased salivation
Scopolamine
Therapeutic Uses
Spastic conditions of the GI & Urinary tract Chronic Asthma Preanesthia - decreases salivation Decreases excitement Produces amnesia Dysrhythmias
Effects of Cholinergic Blockers
brain- excitement followed by depression eyes- pupill dilation; poorer visoin salivation- decreased bronchi- dilated, decreased secretions heart-rate increased GI tract- decreased secretion & motility bladder- poor muscle tone; urine retention
Cholinergic Blockers Drug Interactions
Slows GI motility = dec. absorption
Inc. contact with GI increases adverse effects
Antacids & antidiarreals decrease absorption
Cholinergic agents cancel effect
Anticholinergics may give added effects
Cholinergic Blockers Adverse Reactions
Dose is critical - small therapeutic range to toxicity
Small Dose - decrease salivation, decrease perspiration, heat intolerance
Mod. - Hi Dose - pupils dilate, decrease visual accommodation, heart rate up, hallucinate
Higher Dose- not able to urinate, no GI motility or secretions
OD symptoms
cholinergic Blockers
all Sx exaggerated HOT as a hare BLIND as a bat DRY as a bone MAD as a hatter
Cholinergic Blockers
Unpredictable Adverse Reactions
Increased intraocular pressure
Eye Pain
Blindness
Cholinergic Blockers
Nursing Implications
Use cautiously in pt with CAD, CHF, dysrhymmias
Monitor urine output
Monitor temperature esp. if hot
Avoid substances the inc. gastric acidity
(ETOH, nicotine, caffeine, ASA)
Screen for glaucoma
Teach about signs of toxicity
Adrenergic Agents
Sympathomimetics
Cause Flight or Fight
Catecholamines - one type
Example - Epinephrine
Adrenergic Agents
Site and Actions
Alpha receptors= Blood Vessels - constriction
Beta 1 receptors = Heart - increase
Beta 2 receptors = Bronchial dilation
May be combinations of all three actions
Adrenergic Agents
Therapeutic Uses- ALPHA
relieve hypotension, anaphylactic shock
Therapeutic Uses- BETA 1
bradycardia, heart block
Therapeutic Uses- Beta 2
asthma, emphysema, allergic reaction
Therapeutic Uses- dopaminergic receptors
dilates renal arteries in ARF (acute renal faliure)
Adrenergic Agents
Drug Interactions
Additive Effect Sympathomimetics Cholinergic Blockers Decreased Effect Cholinergic Agonist MAO inhibitors, Digoxin (decrease heart rate), Antihistamines (dry dry dry)
Adrenergic Agents
Adverse reactions
CNS, Cardiac, Skeletal Muscle, GI
CNS - common HA, restless, nervous, anxious
Cardiac - palpitations, tachycardia, BP fluctuations, angina
Skeletal Muscle- weakness, tremors
GI - N, severe vomiting, diarrhea
Adrenergic Agents
Nursing Implications
Cautiously in elderly, dysrhymmias, confused or CVA
Cautiously in HTN, DM, Parkinson’s
Monitor for signs of OD - HA, V, hypotension or HTN, chest pain
Prolonged use - edema, oliguria, hemorrhage
Teach to rinse mouth to decrease dryness
Noncatecholamines
Action maybe direct effect on sympathetic receptor
most typical for bronchiodilators
nose bleed- topically- constricuts bleeding vessels
Indirect by stimulating release of norepinephrine
Absorbed well po
Often given by inhalation to decrease systemic effects
Noncatecholamines
Therapeutic Uses
Bronchodilator - Asthma, Emphysema, Ch. Bronchitis
Vasoconstriction - Hypotension, Nose bleeds
Cardiac Stimulation - bradycardia
Smooth muscle relaxant - stop labor
Direct Acting
ex’s (2)
Alupent - beta 2 selective bronchodilator for asthma
Brethine (terbutaline) direct acting beta 2 selective for asthma
Used in OB to delay delivery by relaxing uterus in PTL (Tocolytic)
Noncatecholamines
Drug interactions
MAO inhibitors
Beta Blockers
Sympathomimetics
Many others OTC have many additive effects
Noncatecholamines
Adverse reactions
CNS- HA, restless, insomnia, dizziness
C-V - HTN or low BP, palpitations, bradycardia, tachycardia, arrest
Skel-Mus.- weakness, cramps
Resp.- bronchial spasms
Nursing Implications - same as catecholimines
Adrenergic Blockers (sympatholytics)
Disrupt sympathetic nervous function
Interrupts action of adreneric
Decreases available norepinephrine
Specific to sign of block - alpha or beta
Alpha Adrenergic Blockers (2)
erogtamine
regitine
Smooth muscle relaxation
Peripheral vasodilatation (lowers BP)
Migraine Headaches
Used for peripheral vascular disease - Raynaud’s
Frost bite, Septic shock (not primary Rx in HTN)
Alpha Adrenergic Blockers
Drug Interactions
Cholinergic agonist- synergistic
Sympathomimetics - opposite
Alpha Adrenergic Blockers
Adverse Reactions
Orthostatic Hypotension
Angina - MI
CNS - tingling, numbness, HA
some Anemias, rashes, allergic reactions
Alpha Adrenergic Blockers
Nursing Implications
Do not use in pt with MI, CHF, angina, Caution with renal insuff., ulcers, CAD Assess signs of vascular insuff. Monitor BP sitting, standing Advise - no ETOH, other OTC Take early if for migraine HA
BETA Adrenergic Blockers
Inhibit action of Catecholamines Maybe selective or non-selective Inderal (propranolol)- for HTN, Angina, dysrhymmias Lopressor (metoprolol) - HTN & MI Timoptic (timolol) glaucoma LOL
Beta Blockers
Adverse reactions
low in frequency
dose dependent
more for IV use, elderly, hepatic or renal insuff.
Bradycardia and Hypotension
Beta Blockers
nursing implications
Assess C-V system
Check Apical Pulse notify MD if <60/min and hold
Teach pt & Family effects & adverse effects
No ETOH, smoking, OTC
Not for pt with respiratory conditions = bronchospasm