ANS Cholinergic Blocking Drugs - by fjhuangjun

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									Cholinergic – Blocking Drugs
      Cholinergic-Blocking Drugs

 Describe the cholinergic-blocking drug effects on
 major body systems.

 Discuss the nursing process in the care of patients
 receiving cholinergic-blocking drugs for
 cardiovascular, respiratory, gastrointestinal, and
 genitourinary system problems.
         Cholinergic-Blocking Drugs
           Mechanism of Action
Drugs that block or inhibit the actions of acetylcholine (ACh)
  in the parasympathetic nervous system (PSNS)
 anticholinergics
 Compete with Ach & block ACh at the muscarinic receptors
  in the PSNS
   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
Cholinergic-Blocking Drugs
          Cholinergic-Blocking Drugs
                Chemical Class
Natural       Synthetic/          Semisynthetic
atropine    benztropine (Cogentin)
Belladonna dicyclomine (Bentyl)    glycopyrrolate
Hyoscyamine homatropine            ipratropium
Scopolamine isopropamide           methscopolamine
            oxybutynin (Ditropan) propantheline
            tolterodine (Detrol)
            solifenacin (Vesicare)
      Cholinergic-Blocking Drugs
 Atropine – preop; bradycardia;
 Dicyclomine (Bentyl) – irritable bowel syndrome
 glycopyrrolate (Robinul) – intraop to control secretions;
  PUD (peptic ulcer disease), reversal of neuromuscular
 Oxybutynin (Ditropan) – antispasmodic for neurogenic
  bladder; overactive bladder; spinal cord injury
 Scopolamine (Transderm-Scop) – control of secretions;
  motion sickness
 Tolterodine (Detrol) – overactive bladder
      Cholinergic-Blocking Drugs
             Drug Effects
 Cardiovascular
    Small doses: decrease heart rate
    Large doses: increase heart rate
    Small doses: decrease muscle rigidity
     and tremors
    Large doses: drowsiness, disorientation, hallucinations
 Respiratory
    Decreased bronchial secretions
    Dilated bronchial airways
        Cholinergic-Blocking Drugs
               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
     Cholinergic-Blocking Drugs
            Drug Effects
 Genitourinary
   Relaxed detrusor muscle
   Increased constriction of internal sphincter
   Result: urinary retention

 Glandular
   Decreased bronchial secretions, salivation, sweating
    Cholinergic-Blocking Drugs
         Indications - CNS

 To decrease muscle rigidity and muscle tremors
    Parkinson’s disease
    Drug-induced extrapyramidal reactions
      Cholinergic-Blocking Drugs
     Indications - Cardiovascular
Affect the heart’s conduction system
 Low doses: slow the heart rate
 Appropiate doses: block inhibitory vagal effects on the SA
  and AV node pacemaker cells
   Intended Effect: increased heart rate
 Uses:
   Diagnosis of sinus node dysfunction
   Symptomatic second-degree heart block
   Severe sinus bradycardia with hemodynamic
    compromise (advanced life support)
Cholinergic-Blocking Drugs
Indications – Respiratory
 Blocking the cholinergic stimulation of the PSNS
  allows unopposed action of the SNS
 Results
    Decreased secretions from nose, mouth, pharynx,
    Relaxed smooth muscles in bronchi and bronchioles
       Bronchodilation
   Decreased airway resistance
Cholinergic-Blocking Drugs
Indications - Respiratory
Respiratory drugs are used to treat:

 Exercise-induced bronchospasms
 Chronic bronchitis
 Asthma
 Chronic obstructive pulmonary disease
      Cholinergic-Blocking Drugs
     Indications - Gastrointestinal
 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

Gastrointestinal drugs are used to treat:
 Irritable bowel disease
 GI hypersecretory states
 Acute pancreatitis (reduces gastric and pancreatic secretions)
     Cholinergic-Blocking Drugs
     Indications - Genitourinary

 Reflex neurogenic bladder
 Incontinence
Cholinergic-Blocking Drugs
    Other Indications


    to reduce salivary secretions
         Cholinergic-Blocking Drugs
              Adverse Effects
Body System        Adverse Effects
Cardiovascular     Increased heart rate, dysrhythmias
CNS                Excitation, restlessness, irritability,
                   disorientation, hallucinations, delirium
Eye                Dilated pupils, decreased visual accommodation,
                   increased intraocular pressure
Gastrointestinal   Decreased salivation, decreased gastric
                   secretions, decreased motility
Genitourinary      Urinary retention
Glandular          Decreased sweating
Respiratory        Decreased bronchial secretions
      Cholinergic-Blocking Drugs
 Antihistamines
 phenothiazines
 tricyclic antidepressants

 When given with cholinergic blocking drugs, cause
 additive effects, resulting in increased effects
         Cholinergic-Blocking Drugs
           Nursing Implications
 These drugs will block the action of ACh in the PSNS
 Assess for allergies, presence of BPH, glaucoma,
    tachycardia, MI, HF, hiatal hernia, and GI or GU
   Perform baseline assessment of vital signs and systems
   Medications should be taken exactly as prescribed to
    have the maximum therapeutic effect
   Overdosing can cause life-threatening problems
   Blurred vision may cause problems with driving or
    operating machinery
         Cholinergic-Blocking Drugs
           Nursing Implications
 Patients may experience sensitivity to light – sun glasses

 When giving ophthalmic solutions, apply pressure to
  the inner canthus to prevent systemic absorption

 Dry mouth may occur: chewing gum, frequent mouth care,
  and hard candy

 Check with physician before taking any other medication,
  including OTC medications

 Antidote for atropine overdose is physostigmine
   Cholinergic-Blocking Drugs
 Nursing Implications – Patient Ed
 Anticholinergics taken by the elderly patient may lead
 to higher risk for heatstroke due to effects on heat-
 regulating mechanisms

 Teach patients to limit physical exertion and avoid
 high temperatures and strenuous exercise

 Emphasize the importance of adequate fluid and salt
          Cholinergic-Blocking Drugs
              Patient Education
  Patients should report the following to their
 Urinary hesitancy and/or retention
 Constipation
 Palpitations
 Tremors, confusion, sedation or amnesia,
 Excessive dry mouth
   especially if pt. chronic lung infections or disease
 Fever
     Cholinergic-Blocking Drugs
       Nursing Implications
Monitor for therapeutic effects

 For patients with Parkinson’s disease: fewer
 tremors and decreased salivation and drooling

 For urologic problems: improved urinary patterns,
 less hypermotility, increased time between voiding

             Monitor for adverse effects

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