Deck 34: Agents That Affect Intestinal Motility

Question 1

Differentiate between the two newest laxative products,Ceo-Two and lubiprostone (Amitiza),and select the statement that best explains the mechanism of action of these agents.

A) Lubiprostone (Amitiza) releases carbon dioxide gas, which pushes on the wall of the rectum, inducing muscle contractions and stool movement. Ceo-Two opens the chloride channels so that chloride followed by water enters the channels in an attempt to maintain isotonic balance, accelerating transit time and stool softening.
B) Ceo-Two releases carbon dioxide gas, which pushes on the wall of the rectum, inducing muscle contractions and stool movement. Lubiprostone (Amitiza) opens the chloride channels so that chloride followed by water enters the channels in an attempt to maintain isotonic balance, accelerating transit time and stool softening.
C) Lubiprostone (Amitiza) and Ceo-Two open the chloride channels so that chloride followed by water enters the channels in an attempt to maintain isotonic balance, accelerating transit time and stool softening.
D) Ceo-Two releases carbon dioxide gas, which pushes on the wall of the rectum, inducing muscle contractions and stool movement. Lubiprostone (Amitiza) stimulates mu receptors in the myenteric plexus to decrease peristalsis, constrict sphincters, and directly affect the circular smooth muscle of the bowel, speeding gastrointestinal transit time.

Answer 1

Ceo-Two releases carbon dioxide gas, which pushes on the wall of the rectum, inducing muscle contractions and stool movement. Lubiprostone (Amitiza) opens the chloride channels so that chloride followed by water enters the channels in an attempt to maintain isotonic balance, accelerating transit time and stool softening.

Question 2

Explain the mechanism of action of the emollient laxatives.

A) The emollient laxatives work by releasing carbon dioxide gas. The gas pushes against the rectum wall, inducing muscle contraction and stool movement.
B) The emollient laxatives are natural fibers or grains that remain in the intestine, soak up water, and expand. The water, which is retained, softens the stool, and the swelling action distends the rectum and initiates defecation.
C) The emollient laxatives are a mixture of sodium and magnesium salts. These ions attract water, which causes a more liquid stool to be formed.
D) The emollient laxatives act on the stool to permit water to penetrate the fecal mass. The oily nature of these laxatives eases the passage of the stool through the rectum.

Answer 2

The emollient laxatives act on the stool to permit water to penetrate the fecal mass. The oily nature of these laxatives eases the passage of the stool through the rectum.

Question 3

Identify the mechanism used in the classification of diarrheas.

A) The mechanism used in the classification of diarrheas includes diarrheas caused by increased motility in the GI tract.
B) The mechanism used in the classification of diarrheas includes diarrheas caused by increased secretory functions.
C) The mechanism used in the classification of diarrheas includes diarrheas caused by increased osmolality in the intestine.
D) All of these are correct.

Answer 3

All of these are correct.

Question 4

Select the primary causes of constipation.

A) Poorly developed toilet habits and diets low in fiber
B) Stressful situations that result in sympathetic stimulation that decreases intestinal motility
C) Emotional disturbances that alter the parasympathetic control of the intestines
D) All of these are correct.

Question 5

Identify the definition of peristalsis.

A) Peristalsis is the process of discharging the contents of the intestines.
B) Peristalsis is the process in which water moves across membranes following the movement of sodium ions.
C) Peristalsis is a movement characterized by circular contraction and relaxation that propels or moves contents of the GI tract.
D) None of these are correct.

Question 6

Select the group of drug agents that contribute to increased intestinal motility,resulting in diarrhea.

A) NSAIDs, antacids, chemotherapy agents
B) Antiarrhythmic and blood pressure medications
C) Antibiotics and laxatives
D) All of these are correct.

Question 7

Use critical thinking to select the drug of choice for the treatment of constipation in a patient who is taking opioid-based analgesics for the relief of pain following extensive back surgery.

A) Lubiprostone
B) Lactulose
C) Methylnaltrexone bromide
D) Polycarbophil

Question 8

Summarize the residual physical effects associated with diarrhea that continues over a long time.

A) As diarrhea continues, the rectum loses its ability to control the contractions of the rectum, necessary in normal defecation.
B) As diarrhea continues over a long time, large quantities of water, sodium, potassium, and chloride are lost or excreted in the fluid stool. This loss results in dehydration and electrolyte imbalance.
C) As diarrhea continues, the impulses from the brain that prevent untimely defecation weaken and the external anal sphincter relaxes.
D) All of these are true.

Question 9

Select the statement that best describes the reason why the osmotic laxatives are contraindicated in patients with impaired renal function or congestive heart failure.

A) The sodium and chloride ions that are absorbed from osmotic laxatives cause an increase in water retention that will strain the kidneys trying to maintain fluid balance in the body and force the heart to work more forcefully to pump the blood.
B) The sodium and potassium ions that are absorbed from osmotic laxatives cause an increase in water retention that will strain the kidneys trying to maintain fluid balance in the body and force the heart to work more forcefully to pump the blood.
C) The sodium and magnesium ions that are absorbed from osmotic laxatives cause an increase in water retention that will strain the kidneys trying to maintain fluid balance in the body and force the heart to work more forcefully to pump the blood.
D) None of these are correct.

Question 10

Using your knowledge of the causes and treatments of diarrhea,select the correct recommendation for a patient who comes into the office asking for advice to prevent diarrhea while he is away on a business trip overseas.

A) Lotronex taken daily (0.5-1 mg two times a day)
B) Pepto-Bismol, taken prophylactically (2 tablets or 2 oz four times a day)
C) Imodium A-D taken prophylactically (4 mg up to 8 mg per day)
D) All of these are correct.

Question 11

Use the mechanism of action to select the statement that best describes how you would explain to a patient how the adsorbent class of drugs used in the treatment of simple diarrhea works.

A) The adsorbents work in the intestine to form a complex with irritating substances such as bacteria, digestive enzymes, or toxins and carry them into the feces for elimination.
B) The adsorbents remain in the intestine, soak up water, and expand. The water, which is retained, softens the stool, and the swelling action distends the rectum and initiates defecation.
C) The adsorbents are a mixture of sodium and magnesium salts. These ions attract water, which causes a more liquid stool to be formed.
D) The adsorbents act on the stool to permit water to penetrate the fecal mass. The oily nature of these laxatives eases the passage of the stool through the rectum.

Question 12

Select the statement that best describes the reason why antidiarrheals containing atropine should not be used by patients who have glaucoma.

A) Anticholinergic drugs may increase intraocular pressure by reducing posterior chamber drainage in patients with glaucoma.
B) Anticholinergic drugs may increase intraocular pressure by reducing anterior chamber drainage in patients with glaucoma.
C) Anticholinergic drugs may increase intraocular pressure by increasing the fluid production in the anterior chamber of the eye in patients with glaucoma.
D) None of these are correct.

Question 13

Using your knowledge of the treatments for constipation,explain to a patient how laxatives and cathartics stimulate defecation.

A) Both laxatives and cathartics produce a mild, gentle stimulus for defecation.
B) Cathartics produce a mild, gentle stimulus for defecation, whereas laxatives produce a more intense action on the bowel.
C) Laxatives produce a mild, gentle stimulus for defecation, whereas cathartics produce a more intense action on the bowel.
D) Both laxatives and cathartics produce a more intense action on the bowel, causing defecation.

Question 14

Select the true statement related to the treatment of diarrhea with difenoxen (Motofen).

A) Side effects including nausea, vomiting, and hypotension are seen with larger doses, 40 to 60 mg.
B) Difenoxen is a mu receptor agonist that stimulates mu receptors in the myenteric plexus to decrease peristalsis, constrict sphincters, and directly affect the circular smooth muscle of the bowel, prolonging gastrointestinal transit time.
C) At therapeutic doses up to 20 mg per day, difenoxen can produce weak side effects, including euphoria.
D) All of these are correct.

Question 15

Describe the patient population in which chronic diarrhea develops more readily.

A) Children
B) Individuals in poor health or with poor nutrition
C) Elderly
D) All of these are correct

Question 16

Outline the steps in the formation of feces.

A) Contractions of the small intestine move digested food and chyme toward the colon. The large intestine removes water and minerals from the residual waste product and compresses the waste into feces for excretion through the rectum.
B) Contractions of the large intestine move digested food and chyme toward the rectum. The rectum removes water and minerals from the residual waste product and compresses the waste into feces for excretion through the anus.
C) Contractions of the stomach move digested food and chyme toward the small intestine. The small intestine removes water and minerals from the residual waste product and compresses the waste into feces for excretion through the rectum.
D) None of these are correct.

Question 17

Select the statement that best describes the involvement of the sympathetic and parasympathetic nervous system in the movement of feces.

A) Stimulation of the adrenergic fibers that innervate the intestines increases intestinal motility, whereas stimulation of the cholinergic fibers decreases motility.
B) Stimulation of the cholinergic fibers that innervate the intestines increases intestinal motility, whereas stimulation of the adrenergic fibers decreases motility.
C) Stimulation of the cholinergic fibers that innervate the intestines increases intestinal motility, whereas antagonism of the adrenergic fibers decreases motility.
D) None of these are correct.

Question 18

Select the statement that best explains why increased dietary fiber is a major component in the management of constipation.

A) Fiber increases stool bulk and fluid content and decreases transit time, resulting in an increase in the frequency of defecation.
B) Fiber decreases stool bulk and fluid content and increases transit time, resulting in a decrease in the frequency of defecation
C) Fiber decreases the microorganisms in the GI tract, increases the fluid content, and decreases transit time, resulting in an increase in the frequency of defecation
D) None of these are correct.

Question 19

Using onset of action as the basis,select the group of laxatives listed in the order of increasing onset-of-action times.

A) Bowel evacuants, emollients, stool softeners
B) Emollients, bowel evacuants, swelling agents
C) Osmotic laxatives, emollients, bowel evacuants
D) Stimulants, stool softeners, emollients

Question 20

Using acute and chronic diarrhea as the basis,select the correct information to give to a patient who is not aware that there is a difference.

A) Acute diarrhea is associated with the production of loose stools in otherwise healthy individuals that lasts less than 7 days, and diarrhea that lasts more than 10 days is defined as chronic and is accompanied by weight loss, muscle weakness, and electrolyte imbalance.
B) Acute diarrhea is associated with the production of loose stools in otherwise healthy individuals that lasts less than 10 days, and diarrhea that lasts more than 15 days is defined as chronic and is accompanied by weight loss, muscle weakness, and electrolyte imbalance.
C) Acute diarrhea is associated with the production of loose stools in otherwise healthy individuals that lasts less than 14 days, and diarrhea that lasts more than 30 days is defined as chronic and is accompanied by weight loss, muscle weakness, and electrolyte imbalance.
D) Acute diarrhea is associated with the production of loose stools in otherwise healthy individuals that lasts less than 3 days, and diarrhea that lasts more than 7 days is defined as chronic and is accompanied by weight loss, muscle weakness, and electrolyte imbalance.