Cholinergic Blocking Drugs

Question 1

Cholinergic-Blocking Drugs

AKA anticholinergics, parasympatholytics, and antimuscarinic drugs

Answer 1

-drugs that block or inhibit the actions of ACh in the PNS

Question 2

MOA of cholinergic-blocking drugs

Answer 2

• competitive antagonists
• compete with ACh for binding at muscarinic receptors in the PNS
• When these drugs bind to receptors, they inhibit nerve transmission at these receptors

Question 3

Cholinergic-Blocking drug effects on cardiovascular

Answer 3

increased in large doses

Question 4

cholinergic-blocking drug effects on CNS

Answer 4

small doses-excitation

Lg doses- drowsy, diorientation

Question 5

cholinergic-blocking drug effects on Eye

Answer 5

mydriasis

decreased accomodation

Question 6

Cholinergic-blocking drug effects on GI

Answer 6

decreased secretions, motility, peristalsis, relaxed smooth muscle tone

Question 7

Cholinergic-blocking drug effects on GU

Answer 7

relaxed detrusor muscle

increased constriction of internal sphincter

Question 8

Cholinergic-blocking drug Respiratory

Answer 8

decreased bronchial secretions

dilated bronchial airways

Question 9

Indications for cardiovascular

Answer 9

• affects the hearts conduction system
  
  • low doses: slow HR
  • high doses: block inhibitory vagal effects on SA and AV node pacemaker cells

Question 10

Indications for Respiratory

Answer 10

-Blocking the cholinergic stimulation of the PSNS allows unopposed action of the SNS

Question 11

Indications for respiratory

Answer 11

-the PNS controls gastric secretions and smooth muscles that produce gastric motility

Question 12

Toxicity and Overdose

Answer 12

• symptomatic and supportive therapy
• Continuous electrocardigraphic monitoring
• activated charcoal
• Treatment of shock
• Physostigmine

Question 13

Atropine

Answer 13

• naturally occurring antimuscarininc
• uses: brady, ventricular asystole, antidote for anticholinesterase inhibitor taxicity or poisoning, and preoperatively to reduce salivation and GI secretions
• contraindications: angle-closure glaucoma, advanced hepatic and renal dysfunction, hiatal hernia associated with reflux esophagitis, intestinal atony, obstructive GI or GU condtions, and severe ulcerative colitis

Question 14

Dicyclomine (Bentyl)

Answer 14

• synthetic antispasmodic cholinergic blocker
• uses: functional distrubances of GI motility such as IBS
• contraindications: known hypersensitivity to anticholinergics, angle-closure glaucoma, GI tract obstruction, myashtenia gravis, paralytic ileus, GI atony, and toxic megacolon

Question 15

Glycopyrrolate (Robinul)

Answer 15

• synthetic antimuscarinic drug
• blocks receptor sites in the autonomic nervous system that control the production of secretions
• use: preoperatively to reduce salivation and excessive secretions in the repiratory and GI tract
• can also be given IV as antidote to cholinergic meds

Question 16

Oxybutynin (Ditropan)

Answer 16

• synthetic antimuscarinic drug
• PO transdermal patch, topical gel
• uses: overactive bladder and antispasmodic for neuogenic bladder associated with spinal cord injuries and congenital conditions such as spina bifida
• DRY MOUTH

Question 17

Scopolamine

Answer 17

• naturally occuring cholinergic blocker and one of the principal belladonna alkaloids
• uses: prevention of motion sickness and to help prevent postop, postanesthesia N/V
• contraindications: angle-closure glaucoma, advanced hepatic and renal dysfunction, hiatal hernia associated with reflux exophagitis, intestinal atony, obstructive GI or GU conditions, and severe ulcerative colitis
• AE: drowsiness, dry mouth, and blurred vision
• Using scopolamine with CNS depressants or alcohol may increase sedation

Question 18

Tolerodine (Detrol)

Answer 18

• muscarinic receptor blocker
• PO-ER capsule
• uses: urinary frequency, urgency, and urge incontinence caused by bladder overactivity
• newer drugs are associated with a much lower incidence of dry mouth, partly because of their pharmacologic specificity for the bladder as opposed to the salivary glands

Question 19

Mirabegron (Myrbetriq)

Answer 19

• Newer agent used to treat overactive bladder
• Beta3 agonist; represents a new class of therapy for this condition- NOT AN ANTICHOLINERGIC
• does not have same side effects as other drugs to treat overactive bladder

Question 20

SAFETY ALERT

BEERS

Answer 20

anticholinergic drugs are potentially inappropriate for use in geriatric patients

Question 21

What is the antidote for atropine overdose?

Answer 21

Physostigmine