Cholinergic-Blocking Drugs

Question 1

Cholinergic-Blocking Drugs

Answer 1

Drugs that block or inhibit the actions of ACh in the PNS

Question 2

Cardiovascular Drug Effects

Answer 2

Small doses: Decrease heart rate

Large doses: Increase heart rate

Question 3

CNS Drug Effects

Answer 3

Small doses: Decrease muscle rigidity and tremors

Large doses: Drowsiness, disorientation, hallucinations

Question 4

Eye Drug Effects

Answer 4

Dilated pupils (Mydriasis)

Decreases accommodation by paralysis of ciliary muscles (Cycloplegia)

Question 5

GI Drug Effects

Answer 5

Relax smooth muscle tone

Decrease intestinal/gastric secretions

Decrease motility and peristalsis

Question 6

GU Drug Effects

Answer 6

Relaxed detrusor muscle

Increased constriction of internal sphincter

Urinary retention

Question 7

Glandular Drug Effects

Answer 7

Decreased bronchial secretions, salivation, and sweating

Question 8

Respiratory Drug Effects

Answer 8

Decreased bronchial secretions

Dilated bronchial airways

Question 9

CNS Indications

Answer 9

Decreasing muscle rigidity and muscle tremors

Parkinson’s disease

BENZTROPINE (CONGENTIN)

Question 10

Cardiovascular Indications

Answer 10

Affects heart’s conduction system

Low doses slow the heart

High doses block inhibitory vagal effects on SA and AV nodes; results in INCREASED heart rate; ATROPINE

Question 11

Respiratory Indications

Answer 11

Decreased secretions, relaxed smooth muscles, decreased airway resistance, bronchodilation

Used to treat bronchospasms, chronic bronchitis, asthma, and COPD

Question 12

GI Indications

Answer 12

Used to treat IBD and GI hypersecretory states

Decreased secretions, relaxation of smooth muscle, decreased motility and peristalsis

Question 13

GU Indications

Answer 13

Reflex neurogenic bladder

Incontinence

Question 14

Contraindications

Answer 14

Known drug allergy
Angle-closure glaucoma
Acute asthma or respiratory distress
Myasthenia gravis
Acute cardiovascular instability
GI or GU tract obstruction

Question 15

Toxicity and Overdose

Answer 15

Symptomatic and supportive therapy
Continuous ECG monitoring
Activated charcoal
Treatment of shock
PHYSOSTIGMINE

Question 16

Interactions

Answer 16

Amantadine, antihistamines, phenothiazines, tricyclic antidepressants, digoxin

Causes additive cholinergic effects when given with other cholinergic blocking drugs

Question 17

Atropine

Answer 17

Used for bradycardia, ventricular asystole, antidote for anticholinesterase inhibitor toxicity or poisoning, and preoperatively to reduce salivation/secretions

Contraindicated for glaucoma, hepatic/renal dysfunction, hiatal hernia, intestinal atony, obstructive GI or GU, ulcerative colitis

Question 18

Oxybutynin (Ditropan)

Answer 18

Synthetic antimuscarinic drug

Used for overactive bladder and antispasmodic for neurogenic bladder associated with spinal cord injuries

Contraindicated for drug allergy, urinary/gastric retention, glaucoma

Question 19

Scopolamine

Answer 19

One of the principal belladonna alkaloids

Used to prevent motion sickness and prevent post-op nausea and vomiting

Contraindicated for glaucoma, hepatic/renal dysfunction, hiatal hernia, intestinal atony, obstructive GI or GU, ulcerative colitis

Used with CNS depressants can increase sedation

Question 20

Nursing Implications

Answer 20

Assess for BPH, urinary retention, glaucoma, tachycardia, MI, heart failure, hernia, obstruction

Take medications exactly as prescribed

Blurred vision will cause problems with driving or operating machinery