DRUGS FOR GI DISORDERS CHAPTER 8

GI Disorders COMMON DISEASES OF GI SYTEM INCLUDES 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 Proton pump inhibitors- omeprazole Helicobacter pylori (H. pylori) agents- antimicrobials- amoxicillin; bismuth subsalicylate ; 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

Adverse reactions 1. The common side effects are Headache, dizziness, diarrhea and muscular pain, skin rash 2.CNS effects: confusion, disorientation and hallucination 3. Endocrine system effects: gynecomastia, impotency, galactorrhea

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

Adverse reactions 1) G.I reactions: nausea, vomitting, diarrhea, abdominal pain etc. 2) Nervous System: headache, swirl, insomnia, peripheral neuritis, etc. 3) Overgrowth of bacteria: Increases in gastric bacterial concentrations. 4) Hypergastrinemia 5) Canceration

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-HT 3 (serotonin) receptor antagonists- dolasetron (Anzemet) Miscellaneous- scopolamine (Transderm scopolamine)

Drug Selection Depends on cause of nausea and vomiting 5-HT 3 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