Pharmacology: Chapter 51: Bowel Disorder Drugs

When administering mineral oil, the nurse recognizes that it can interfere with the absorption of which substance? a. Fat-soluble vitamins b. Water-soluble vitamins c. Minerals d. Electrolytes

ANS: A Mineral oil can decrease the absorption of fat-soluble vitamins (A, D, E, and K). The other options are incorrect.

A patient will be taking bismuth subsalicylate (Pepto-Bismol) to control diarrhea. When reviewing the patient's other ordered medications, the nurse recognizes that which medication or medication class will interact significantly with the Pepto-Bismol? a. Oral hypoglycemic drugs b. Antibiotics c. acetaminophen (Tylenol) d. Antidepressants

ANS: A Taking oral hypoglycemic drugs with an adsorbent such as bismuth subsalicylate may result in decreased absorption of the hypoglycemic drugs. The other options are incorrect.

A patient is taking tegaserod (Zelnorm) to treat irritable bowel syndrome (IBS). The nurse will monitor this patient for which adverse effect? a. Chest pain b. Chronic constipation c. Abdominal cramps d. Elevated blood glucose levels

ANS: A Tegaserod (Zelnorm) has been associated with serious adverse effects, including angina, heart attacks, and stroke. Abdominal cramps and chronic constipation are symptoms of irritable bowel disease. Elevated blood glucose levels are not an adverse effect of tegaserod.

A patient asks the nurse about the difference between diphenoxylate with atropine (Lomotil) and the over-the-counter drug loperamide (Imodium). Which response by the nurse is correct? a. "Lomotil acts faster than Imodium." b. "Imodium does not cause physical dependence." c. "Lomotil is available in suppository form." d. "Imodium is a natural antidiarrheal drug."

ANS: B Although the drug exhibits many characteristics of the opiate class, physical dependence on loperamide has not been reported. All antidiarrheal drugs are orally administered. The other options are incorrect.

The nurse is reviewing the mechanism of action of antidiarrheal drugs. Which type of antidiarrheal medication works by decreasing the intestinal muscle tone and peristalsis of the intestines? a. Adsorbents such as Pepto-Bismol b. Anticholinergics such as belladonna alkaloids c. Probiotics such as Lactinex d. Lubricants such as mineral oil

ANS: B Anticholinergic drugs work to slow peristalsis by reducing the rhythmic contractions and the smooth muscle tone of the gastrointestinal tract. The other options are incorrect.

A patient wants to prevent problems with constipation and asks the nurse for advice about which type of laxative is safe to use for this purpose. Which class of laxative is considered safe to use on a long-term basis? a. Emollient laxatives b. Bulk-forming laxatives c. Hyperosmotic laxatives d. Stimulant laxatives

ANS: B Bulk-forming laxatives are the only laxatives recommended for long-term use. Stimulant laxatives are the most likely of all the laxative classes to cause dependence. The other options are incorrect.

The nurse is providing teaching to a patient who will be taking the laxative bisacodyl (Dulcolax). Which statement by the nurse is appropriate during this teaching session? a. "You can crush the laxative tablets for improved action." b. "Take the tablets with water, not milk or juice." c. "This laxative is not known to cause dependence." d. "In a normal bowel pattern, a bowel movement occurs daily."

ANS: B Give bisacodyl only with water because interactions with milk, juices, and antacids may occur. All laxative tablets should be swallowed whole; a normal bowel pattern does not necessarily mean one bowel movement a day. Bisacodyl is a stimulant laxative; this class of laxative is the most likely of all the classes to cause dependence.

The nurse is preparing to administer methylnaltrexone (Relistor), a peripherally acting opioid antagonist. This drug is appropriate for which patient? a. A patient with diarrhea b. A terminally ill patient who has opioid-induced constipation c. A patient who is scheduled for a colonoscopy d. A patient who will be having colon surgery in the morning

ANS: B Methylnaltrexone is approved only for terminally ill (hospice) patients who have opioid-induced constipation. The other options are incorrect.

The nurse is reviewing the uses of oral laxatives. Which conditions are general contraindications to or cautions about the use of oral laxatives? (Select all that apply.) a. Irritable bowel syndrome b. Abdominal pain of unknown origin c. Nausea and vomiting d. Fecal impaction e. Ingestion of toxic substances f. Acute abdominal pain

ANS: B, C, D, F Cautious use of laxatives is recommended in the presence of the following: acute surgical abdomen; appendicitis symptoms, such as abdominal pain, nausea, and vomiting; intestinal obstruction; and undiagnosed abdominal pain. Oral laxatives must not be used with fecal impaction; mineral oil enemas are indicated for fecal impaction. The other options are indications for laxative use.

A laxative has been ordered for a patient. The nurse checks the patient's medical history and would be concerned if which condition is present? a. High ammonia levels due to liver failure b. Diverticulosis c. Abdominal pain of unknown origin d. Chronic constipation

ANS: C All categories of laxatives share the same general contraindications and precautions, including avoidance in cases of drug allergy and the need for cautious use in the presence of the following: acute surgical abdomen; appendicitis symptoms such as abdominal pain, nausea, and vomiting; fecal impaction (mineral oil enemas excepted); intestinal obstruction; and undiagnosed abdominal pain. The other options are possible indications for laxatives.

A patient has been treated with alosetron (Lotronex) for severe irritable bowel syndrome (IBS) for 2 weeks. She calls the clinic and tells the nurse that she has been experiencing constipation for 3 days. The nurse will take which action? a. Advise the patient to increase intake of fluids and fiber b. Advise the patient to hold the drug for 2 days c. Instruct the patient to stop taking the drug and to come to the clinic right away to be evaluated d. Instruct the patient to continue the alosetron and to take milk of magnesia for the constipation

ANS: C Alosetron must be discontinued immediately if constipation or signs of ischemic colitis occur. The other options are incorrect.

When administering a bulk-forming laxative, the nurse instructs the patient to drink the medication mixed in a full 8-ounce glass of water. Which statement best explains the rationale for this instruction? a. The water acts to stimulate bowel movements. b. The water will help to reduce the bulk of the intestinal contents. c. These laxatives may cause esophageal obstruction if taken with insufficient water. d. The water acts as a lubricant to produce bowel movements.

ANS: C Bulk-forming drugs increase water absorption, which results in greater total volume (bulk) of the intestinal contents. Bulk-forming laxatives tend to produce normal, formed stools. Their action is limited to the gastrointestinal tract, so there are few, if any, systemic effects. However, they need to be taken with liberal amounts of water to prevent esophageal obstruction and fecal impaction.

While recovering from surgery, a 74-year-old woman started taking a stimulant laxative, senna (Senokot), to relieve constipation caused by the pain medications. Two weeks later, at her follow-up appointment, she tells the nurse that she likes how "regular" her bowel movements are now that she is taking the laxative. Which teaching principle is appropriate for this patient? a. She needs to be sure to take this medication with plenty of fluids. b. It is important to have a daily bowel movement to promote bowel health. c. Long-term use of laxatives often results in decreased bowel tone and may lead to dependency. d. She needs to switch to glycerin suppositories to continue having daily bowel movements.

ANS: C Long-term use of laxatives or cathartics often results in decreased bowel tone and may lead to dependency. Patients need to be taught that daily bowel movements are not necessary for bowel health.

A patient is severely constipated and needs immediate relief. The nurse knows that which class of laxative will provide the most rapid results? a. Bulk-forming laxative, such as psyllium (Metamucil) b. Stool softener, such as docusate salts (Colace) c. Magnesium hydroxide (MOM) d. Magnesium oxide tablets

ANS: C Saline laxatives such as magnesium hydroxide (MOM) produce a watery stool, usually within 3 to 6 hours of ingestion. Bulk-forming laxatives such as psyllium do not produce a bowel movement rapidly. Stool softeners such as docusate salts do not cause patients to defecate; they simply soften the stool to ease its passage. Magnesium oxide tablets are used as magnesium supplements, not as laxatives.

A patient will be taking bismuth subsalicylate (Pepto-Bismol) to control diarrhea. When reviewing the patient's other ordered medications, the nurse recognizes that which medication will interact significantly with the Pepto-Bismol? a. acetaminophen (Tylenol), an analgesic b. levothyroxine (Synthroid), a thyroid replacement drug c. warfarin (Coumadin), an anticoagulant d. fluoxetine (Prozac), an antidepressant

ANS: C The oral anticoagulant warfarin is more likely to cause increased bleeding times or bruising when coadministered with adsorbents. This is thought to be because the adsorbents bind to vitamin K, which is needed to make certain clotting factors. Vitamin K is synthesized by the normal bacterial flora in the bowel. The other options are incorrect.

A patient is about to undergo a diagnostic bowel procedure. The nurse expects which drug to be used to induce total cleansing of the bowel? a. docusate sodium (Colace) b. magnesium hydroxide (milk of magnesia) c. mineral oil d. polyethylene glycol (GoLYTELY)

ANS: D Polyethylene glycol is a very potent laxative that induces total cleansing of the bowel and is most commonly used before diagnostic or surgical bowel procedures. The other options are incorrect.

The nurse is discussing the use of adsorbents such as bismuth subsalicylate (Pepto-Bismol) with a patient who has diarrhea. The nurse will warn the patient about which possible adverse effects? a. Dark stools and blue gums b. Urinary hesitancy c. Drowsiness and dizziness d. Blurred vision and headache

ANS: A Dark stools and blue gums are two of the possible adverse effects of bismuth subsalicylate (see Table 51-2). The other adverse effects listed may occur with the use of other antidiarrheal drugs.

A patient is receiving lactulose (Chronulac) three times a day. The nurse knows that the patient is not constipated and is receiving this drug for which reason? a. High ammonia levels due to liver failure b. Prevention of constipation c. Chronic renal failure d. Chronic diarrhea

ANS: A Lactulose (Chronulac) produces a laxative effect but also works to reduce blood ammonia levels by converting ammonia to ammonium. Ammonium is a water-soluble cation that is trapped in the intestines and cannot be reabsorbed into the systemic circulation. This effect has proved helpful in reducing elevated serum ammonia levels in patients with severe liver disease. The other options are incorrect.

The nurse is giving oral mineral oil as an ordered laxative dose. The nurse will take measures to prevent which potential problem that may occur with mineral oil? a. Fecal impaction b. Electrolyte imbalances c. Lipid pneumonia d. Esophageal blockage

ANS: C Lipid pneumonia may occur if the oral mineral oil is accidentally aspirated into the respiratory tract. The other options are incorrect.

A patient who has been on antibiotic therapy for 2 weeks has developed persistent diarrhea. The nurse expects which medication class to be ordered to treat this diarrhea? a. Lubricants b. Adsorbents c. Anticholinergics d. Probiotics

ANS: D Probiotics work by replenishing bacteria that may have been destroyed by antibiotic therapy, thus restoring the balance of normal flora and suppressing the growth of diarrhea-causing bacteria.