Exam 4- Week 14 Flashcards
Antacids
Antacids should be taken as prescribed, especially related to mealtimes. For best effects, they should be taken 1 to 3 hours after meals and at bedtime. To prevent chewable tablets from entering the small intestine in undissolved form, they must be chewed thoroughly before they are swallowed and followed with half a glass of water. Suspensions should be shaken before administration. Antacids have many drug interactions when taken concurrently with other drugs because the altered acidity of the stomach affects acid-labile drugs. Calcium-based antacids should not be administered with food containing large amounts of oxalic acid (e.g., spinach, rhubarb) or phytic acid (e.g., bran, cereals). These foods decrease the absorption of calcium.
Loperamide
binds to the opiate receptors of the intestinal wall, leading to slowed gastric motility. It also reduces fecal volume, increases viscosity and bulk, and diminishes the loss of fluid and electrolytes.
Bismuth salicylate
Adverse effects: all patients should be warned about are gray/black stools and black tongue, the results of the bismuth. Patients should be told to expect this reaction and that it does not indicate GI bleeding.
Contraindications: children or teenagers during or after recovery from chickenpox or flu-like illness. It is also contraindicated for patients with aspirin hypersensitivity.
Administration: For acute diarrhea. mg every 30 min or 1,048–1,200 mg every 60 min as needed.
PPIs
•Esomeprazole (Nexium), omeprazole (Prilosec)
•Used to treat GERD, esophagits, gastritis, PUD
•A pro drug – the active form irreversibly combines with the H+,-K+-ATPase proton pump system
–Results in reduced blood flow to stomach, decreased pepsin secretion, and increases serum pepsinogen
Monitoring: H. Pylori. Long-term use of PPIs presents concerns. One concern is the development of precancerous cells due to hypochlorhydria, with enterochromaffin cell–like hyperplasia changes found in chronic PPI use. Another concern is an increase in hip fractures in at-risk patients who are on PPIs longer than 2 years and on higher doses of PPIs. Vitamin B12 deficiency is also a concern with chronic acid suppression.
Omepeazole
Can cause osteoporosis. Calcium needs an acidic environment for optimal absorption. PPIs decrease the excretion of acid and inhibit the absorption of calcium.
Stimulant laxatives
•Bisacodyl (Dulcolax), castor oil, cascara, senna (Ex-Lax, Senokot)
•Used for constipation associated with prolonged bed rest, medications, and as bowel prep for surgery and other procedures
•Act on the intestinal wall of the colon to increase fluids and electrolytes within the intestinal lumen
–Cause the release of prostaglandins and cAMP
•Side effects – cramping, N/V
Fastest working. have a direct action on intestinal mucosa by stimulating the myenteric plexus.
Bisacodyl is to be used with caution in the presence of severe cardiovascular disease. The extract of cascara sagrada contains alcohol and should be avoided by people with alcohol intolerance.
Metoclopramide
For patients with GERD secondary to decreased lower esophageal sphincter pressure (LESP), metoclopramide produces dose-related increases in LESP.
Step-Down Approach to GERD
The step-down approach starts with potent antisecretory agents and then involves incrementally decreasing the potency of therapy until breakthrough symptoms define the treatment necessary for symptom control
Step-Up Approach to GERD
The step-up approach involves incrementally increasing the potency of therapy until symptom control is achieved.
What is the first line therapy for peptic ulcer disease with a positive H. pylori?
PPIs
Treatment of nausea and vomiting
5-HT3 receptor antagonists are being used extensively to treat nausea and vomiting.
Treatment of constipation in children
Constipation in children may be a control issue or signal pathology. Discuss this topic with the parents. A trial of a laxative concurrently with behavior modification is appropriate, but the child needs to be monitored for the need for referral for a GI work-up.
Phenothiazine antiemetics
block dopamine receptors in the chemoreceptor trigger zone (CTZ). They also bind to and block cholinergic, alpha1-adrenergic, and histamine1 receptors.
Docusate
Incorporate water and lipids into the stool which reduces surface tension
Ondansetron
The 5-HT3 receptor antagonists block serotonin both peripherally on vagal nerve terminals and centrally in the CTZ. Chemotherapy causes the release of serotonin from the enterochromaffin cells; pretreatment with a 5-HT 3 receptor antagonist decreases emesis.
