Drugs affecting GI function: Part 2

Question 1

Uses of laxatives

Answer 1

Soften stool
Increase stool volume
Hasten fecal passage through intestine
Facilitate evacuation from the rectum

Question 2

Functions of the colon

Answer 2

Absorb water and electrolytes

Transports wastes

Question 3

Frequency of bowel elimination varies widely from…

Answer 3

2-3 times / day to 2 times / week

Question 4

Proper function of bowel is highly dependent on…

Answer 4

Dietary fiber

Question 5

Fiber…

Answer 5

Absorbs water which softens feces and increases size and can be digested by colonic bacteria whose growth increases fecal mass

Question 6

Constipation is defined as…

Answer 6

Hard stools, infrequent stools, excessive straining, prolonged effort, sense of incomplete evacuation, unsuccessful defection

Question 7

What is the closest thing to dietary fiber that we have?

Answer 7

Bulk-forming laxatives

Question 8

Bulk-forming laxatives indications

Answer 8

Temporary treatment of constipation \Prevention of constipation

Question 9

Adverse effects of bulk-forming laxatives

Answer 9

Systemic reactions (rare) 
Esophageal obstruction  (if taken with insufficient fluids) 
Intestinal obstruction

Question 10

Surfactant laxatives

Answer 10

Fairly benign - first option for a patient
Alter surface tension of stool
Act on intestines

Question 11

Surfactant laxatives: alter surface tension of stool

Answer 11

Allows increased water to enter feces

Question 12

Surfactant laxatives: acto on intestines

Answer 12

Inhibit fluid absorption

Stimulate secretion of water into intestines

Question 13

Surfactant laxatives produce a soft stool…

Answer 13

A few days after onset of treatment

Question 14

Surfactant laxatives example

Answer 14

Colace (docusate)

Question 15

If a patient goes home on a narcotic, you should tell them to take…

Answer 15

Surfactant laxatives

Question 16

Stimulant laxatives actions

Answer 16

Stimulate intestinal motility

Increase water in the intestine

Question 17

Stimulant laxatives: types

Answer 17

Bisacodyl (Correctol, Dulcolax)
Senna
Castor oil

Question 18

Castor oil

Answer 18

Works in the small intestine

Question 19

Stimulant laxatives produce a semi-fluid stool in..

Answer 19

6-12 hours

Question 20

Dulcolax and Senna can cause..

Answer 20

Cramping

Question 21

What is used for colon-prep before a colonoscopy?

Answer 21

Go-lytely

Question 22

Osmotic laxatives actions

Answer 22

Draws water into intestinal lumen

Fecal mass softens and swells, stretching intestinal wall and stimulating peristalsis

Question 23

Adverse effects of osmotic laxatives

Answer 23

Dehydration 
Renal decline (toxicity) 
Sodium retention (exacerbates heart failure, hypertension, edema)

Question 24

Osmotic laxatives examples

Answer 24

Polyethylene glycol (Miralax) 
Sodium phosphate (Fleet) 
Magnesium hydroxide (MOM)

Question 25

Osmotic laxatives onset of action

Answer 25

Soft or semifluid in 6-12 hours; high doses in 2-6 hours

Question 26

Osmotic laxatives are often used in…

Answer 26

Long term care

Question 27

Laxative abuse causes

Answer 27

Misconceptions regarding bowel habits

Over-emptying of the bowel

Question 28

Consequences of laxative abuse

Answer 28

Diminished bowel reflexes
Electrolyte imbalances
Dehydration
Colitis