Lecture 8 Autonomic Nervous System

1
Lecture 8 Autonomic Nervous System

• Parasympathetic
• acetylcoholine (cholinergic)
• Sympathetic
• norepiphrine (adrenergic)

2
(No Transcript)
3
Cholinergic Agonist

• Parasympathomimetic
• Mimics acetylcholine
• Used in Glaucoma, GI statsis, Urine Bladder
  Dysfunction
• Reglan (metoclopramide)

4
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

5
Drug Interactions

• Increased effect with
• anticholinesterase
• ganglionic blockers
• Decreased effect with
• cholinergic blockers (atropine, scopolamine)
• Sympathomimetics (opposite effect)
• Anticholinergics

6
Effects of Parasympathetic System
Pupils constrict better vision
Increased salivation
Bronchial constriction
Heart rate decreased
GI tract increased secretions and motility
Bladder tone better voiding
7
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

8
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)

9
Pilocarpine (cholinergic agonist)

• mimics acetycholine action
• binds to receptor sites of smooth muscles
• Reduces intraocular pressure
• Used in glaucoma and ophalmologic surgery

10
Adverse Reactions

• Blurred vision
• Lid pain
• Rare systemic effects, abd. cramps, increased
  salivation

11
Nursing Implications

• Do not give in acute iritis, corneal abrasion
• Caution with asthma, ulcers, Parkinson's
• Teach pt to take gtts at night

12
Anticholinesterase Agents

• Prostigmine Tensilon
• Facilitate acetylcholine action by inhibiting its
  destruction by actylcholinesterase enzyme
• Used to Dx and Tx myasthenia gravis

13
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

14
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

15
Scopolamine

• Greatest effect in the CNS 1st excitement then
  depression
• pupillary dilation
• decreased salivation

16
Therapeutic Uses

• Spastic conditions of the GI Urinary tract
• Chronic Asthma
• Preanesthia - decreases salivation
• Decreases excitement
• Produces amnesia
• Dysrhythmias

17
Effects of Cholinergic Blockers
Brain- Excitement followed by depression
Eyes- Pupil dilation poorer vision
Salivation- decreased
Bronchi- dilated, decreased secretions
Heart- rate increased
GI tract- decreased secretions motility
Bladder- poor muscle tone, urine retention
18
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

19
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

20
Over Dose Symptoms

• All Sx exaggerated
• HOT as a hare
• BLIND at a bat
• DRY as a bone
• MAD as a hatter

21
Unpredictable Adverse Reactions

• Increased intraocular pressure
• Eye Pain
• Blindness

22
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

23
Adrenergic Agents

• Sympathomimetics
• Cause Flight or Fight
• Catecholamines - one type
• Example - Epinephrine

24
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

25
Therapeutic Uses

• ALPHA- relieve hypotension, anaphylactic shock
• BETA 1 - bradycardia, Heart block
• BETA 2 Asthma, emphysema, allergic reaction
• Dopaminergic receptors- dilates renal arteries in
  ARF
• increases renal profusion

26
Drug Interactions

• Additive Effect
• Sympathomimetics
• Cholinergic Blockers
• Decreased Effect
• Cholinergic Agonist
• MAO inhibitors, Digoxin, Antihistamines

27
Adverse Reactions

• CNS - common HA, restless, nervous, anxious
• Cardiac - palpitations, tachycardia, BP
  fluctuations, angina
• Skeletal Muscle- weakness, tremors
• GI - N, severe vomiting, diarrhea

28
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

29
Noncatecholamines

• Action maybe direct effect on sympathetic
  receptor
• Indirect by stimulating release of norepinephrine
• Absorbed well po
• Often given by inhalation to decrease systemic
  effects

30
Therapeutic Uses

• Bronchodilator - Asthma, Emphysema, Ch.
  Bronchitis
• Vasoconstriction - Hypotension, Nose bleeds
• Cardiac Stimulation - bradycardia
• Smooth muscle relaxant - stop labor

31
Examples of Direct Acting

• 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)

32
Drug Interactions

• MAO inhibitors
• Beta Blockers
• Sympathomimetics
• Many others OTC have many additive effects

33
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

34
Adrenergic Blockers (sympatholytics)

• Disrupt sympathetic nervous function
• Interrupts action of adreneric
• Decreases available norepinephrine
• Specific to sign of block - alpha or beta

35
Alpha Adrenergic Blockers(ergotamine, regitine)

• Smooth muscle relaxation
• Peripheral vasodilatation (lowers BP)
• Migraine Headaches
• Used for peripheral vascular disease - Raynauds
• Frost bite, Septic shock (not primary Rx in HTN)

artery
36
(No Transcript)
37
Drug Interactions

• Cholinergic agonist- synergistic
• Sympathomimetics - opposite

38
Adverse Reactions

• Orthostatic Hypotension
• Angina - MI
• CNS - tingling, numbness, HA
• some Anemias, rashes, allergic reactions

39
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

40
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

41
Adverse Reactions

• low in frequency
• dose dependent
• more for IV use, elderly, hepatic or renal
  insuff.
• Bradycardia and Hypotension

42
Nursing Implications

• Assess C-V system
• Check Apical Pulse notify MD if
• Teach pt Family effects adverse effects
• No ETOH, smoking, OTC
• Not for pt with respiratory conditions
  bronchospasm