Drugs for Treating GI Disorders

Chapter 11

GI Disorders

Peptic Ulcer and Acid Reflux Disorders Laxatives and Cathartics Antidiarrheals Antiemetics

Vomiting

Drugs for Peptic Ulcer and Acid Reflux Disorders

Most of these drugs alter gastric acid and its effects on the mucosa of the upper GI tract

Many promote healing of lesions and prevent recurrence of lesions by decreasing cell destructive effects or increasing cell protective effects

Drug Classes

Antacids- Maalox, Mylanta Histamine-2 receptor antagonists-

cimetidine (Tagamet) Proton pump inhibitors- omeprazole

(Prilosec) Helicobacter pylori (H. pylori) agents-

antimicrobials- amoxicillin; bismuth subsalicylate (Pepto Bismol); combinations

Drug Selection

Proton pump inhibitors are drugs of first choice in most situations- heal more rapidly and may be combined with other drugs for treatment of H. pylori

H-2 antagonists are now over the counter

Antacids are still used to relieve heartburn and abdominal discomfort

Patient Teaching Guidelines

For Gastroesophageal reflux disease (GERD) - elevate head of bed, avoid stomach distention, sit upright for 1 to 2 hrs after eating, minimize acid-producing foods, avoid smoking, lose weight

Take drugs as directed These drugs may prevent absorption of

other drugs taken at the same time Histamine-2 antagonists may alter the

effects of several drugs

Lifespan Considerations

Children Antacids have been approved for use in

children- others have not but have been used in smaller doses

Elderly All these drugs may be used in the elderly Older adults have less gastric acid, so

smaller doses are indicated Monitor for adverse effects

Laxatives and Cathartics

Used to promote bowel elimination, such as in cases of constipation

Laxative implies mild effects Cathartic implies strong effects

Drug Classes

Bulk forming laxatives- methylcellulose (Citrucel)

Surfactant laxatives (stool softeners)- docusate sodium (Colace)

Saline cathartics- milk of magnesia, Fleet enema

Stimulant cathartics- bisacodyl (Dulcolax), castor oil

Lubricant laxatives- mineral oil

Indications for Use

Relief of constipation To prevent straining in patients with

cardiovascular disease (CVD), hypertension, stroke (CVA), and rectal conditions such as hemorrhoids

As a bowel prep To accelerate elimination of potentially

toxic substances

Patient Teaching Guidelines

Diet, exercise, fluid intake can prevent or treat constipation

Eat foods high in dietary fiber- fruits, vegetables, whole grain cereals and breads

Establish regular bowel habits Laxative use should be temporary Take as directed

Lifespan Considerations

Children Glycerin suppositories in younger children Stool softeners in older children Don’t use strong stimulant laxatives Don’t use saline laxatives if under 2 yrs of age

Elderly Constipation is a common problem Laxatives may be overused Strong stimulants should be avoided Metamucil is drug of choice for use on a regular

basis- take with a full glass of liquid

Antidiarrheals

Used to treat diarrhea Drugs may be given to relieve the

symptoms or treat the underlying cause of diarrhea

Drug Classes

Opiate-related drugs- paregoric; diphenoxylate with atropine (Lomotil)

Antibacterial agents- ciprofloxacin (Cipro); metronidazole (Flagyl)

Miscellaneous drugs- bismuth subsalicylate (Pepto Bismol)

Athlete/Patient Teaching Guidelines

Antidiarrheal meds are not always needed Drink plenty of fluids, avoid spicy foods and

fruits and vegetables until diarrhea stops Good handwashing, proper food storage can

prevent diarrhea Take drugs only as needed and as directed See health care provider if diarrhea is

accompanied by abdominal pain or fever

Lifespan Considerations

Children Appropriate fluid replacement is important

in conjunction with medications Elderly

Diarrhea is less common than constipation Excessive laxative use may cause diarrhea Watch for fluid volume deficits Most drugs can be given- watch for

constipation as a complication

Antiemetics

Used to prevent or treat nausea and vomiting from various causes

Drugs from many classes are used to treat nausea and vomiting

Drug Classes

Phenothiazines- promethazine (Phenergan)

Antihistamines- hydroxyzine (Vistaril) Prokinetic agent- metoclopramide

(Reglan) 5-HT3 (serotonin) receptor antagonists-

dolasetron (Anzemet) Miscellaneous- scopolamine (Transderm

scopolamine)

Drug Selection

Depends on cause of nausea and vomiting 5-HT3 receptor antagonists for

chemotherapy or post-op Anticholinergic and antihistamines for

motion sickness promethazine (Phergan)- antihistaminic,

antiemetic, and sedative effects Metoclopramide (Reglan) when non-

obstructive gastric retention

Athlete/Patient Teaching Guidelines

Take early- more effective than when nausea and vomiting have begun

Take fluids to prevent dehydration Lie down and rest to reduce nausea Be aware of safety precautions of drugs Take as directed

Lifespan Considerations

Children Use with caution- few studies have been

done May cause more adverse effects than in

adults Elderly

May cause excessive drowsiness Be aware of dehydration potential May also cause psychoactive effects