Module 3: GI Unit A Flashcards
What are examples of antiacids?
Calcium Carbonate (Tums®, Rolaids®) Sodium bicarbonate (Alka Seltzer) Magnesium (Milk of magnesia) Aluminum (Amphogel®) Bismuth subsalicylate (Pepto-Bismol)
MOA of antiacids?
neutralize hydrochloric acid in the stomach, thereby increasing gastric pH above 4.0
What can Soidum Bicarbinate (Alka Selzter) contribute to?
may contribute to hypertension.
Side effect of Milk of Mag?
may cause diarrhea
What condition would contraindicate the use of Milk of Mag and Aluminum?
Renal insufficiency.
What antiacids can cause a side effect of constipation?
Tums and Aluminum.
Who should avoid Sodium based antacids (Alka Seltzer)?
patients with cardiovascular disease, hypertension, pregnant.
How far should you separate antiacids and other medication administration?
Two hours (either before or after).
What antiacid is contraindicated in pregnancy and why?
Sodium bicarbonate (Alka Seltzer) in pregnancy for risk of fetal alkalosis and/or fluid overload.
Peptobismol also contraindicated
What D2D interaction does Aluminum have?
Warfarin (decreases absorption)
What population should not take Bismuth subsalicylate (Pepto-Bismol)?
pregnancy and lactation and in children less than 12 years of age.
What are examples of H2RAs?
Cimetidine (Tagamet)
Famotidine (Pepcid)
Nizatidine (Axid)
What is the MOA of H2RAs? What is the rate of effectiveness?
Blocks H2 (histamine) receptors to reduce the volume of gastric acid. Faster than PPIs, slower than antacids.
Why does Cimetidine (Tagamet) have significant D2D interactions?
potent CYP INHIBITOR, so many drug-to-drug interactions (warfarin, theophylline, phenytoin opioids)
H2RAs increase risk of:
Potential pneumonia
What H2RA has been pulled from use due to concerns surrounding caricinogens since 4/4/20?
Zantac
What is the indication for H2RAs?
Gastric and duodenal ulcers
What H2RA has the least amount of D2D interactions?
Pepcid
Examples of PPIs:
POLE (end in zole): Pantoprazole (Protonix) Omeprazole (Prilosec) Lansoprazole (Prevacid) Esomeprazole (Nexium)
Indication of PPI use and rate of action:
Gastric and duodenal ulcers. Most effective at suppressing acid but the slowest onset of action compared to antacids and H2RaS
MOA of PPI
Prodrug inhibition of the proton pumps that secret gastric acid.
Increased risk of the following with prolonged PPI use:
Fractures, Pneumonia, TB, Acid rebound C. Diff., Gastric malignancy
Deficiencies in vitamin B-12, calcium, and magnesium (No recommendations for monitoring at this time)
D2D interaction with PPIs
Can reduce the absorption of drugs that rely on acid (aspirin=increase GI bleeds).
What do you need to remember with PPIs as far as deprescribing?
Taper it off to prevent rebound acid.
What is Misoprostol (Cytotec)?
Prostaglandin Analogs
MOA of Cytotec?
Protects gastric mucosa by binding to prostaglandin receptors. This inhibits gastric acid secretion and increases mucus production.
Indication for cytotec use?
Prevention of GI ulcers related to long-term NSAID use.
BBW for cytotec?
uterine contractions. Category X.
MOA of Mucosal Protectant Sucralfate (Carafate)
Creates a protective barrier against pepsin and gastric acid.
Safety considerations and D2D considerations with Sucralfate (Carafate)?
Very few side effects and D2D.
Example of Prokinetic drug?
Metoclopramide (Reglan)
Indication for Reglan use?
Sometimes used for relief of heartburn during pregnancy. (Also antiemetic)
MOA of Reglan?
Dopamine agonist promotes gastric emptying and tones lower esophageal sphincter.
BBW for Reglan?
tardive dyskinesia
Cytotec use in lactation?
not recommended during lactation due to limited studies; however, amounts in breast milk are minimal and adverse events are unlikely.
Odd side effect of PeptoBismol?
Black colored stool
Antiacid and Antiemetic Drugs that prolong QT interval?
Cimetidine (tagamet), Inapsine (Droperidol), Zofran
Which patients should continue gastric protection indefinitely?
Those on chronic NSAIDs, Barrett’s esophagus, active ulcers.
What is the reason that the use of PPIs increases the risk of certain infections? What are they?
Gastric acid helps kill pathogens in the upper and lower GI tract. Increased risk of pneumonia, TB, and Clostridium difficile
What is the purpose of enteric-coated medications?
To protect them through the stomach. The more basic environment in the small intestine causes them to release. Antiacids confuse this method.
Most enteric coatings work by presenting a coated surface that is stable in highly acidic pH (with a pH level of 2.0) such as that found in the stomach but that breaks down rapidly in a less acidic (more basic) pH.
What are prostaglandins and why do we care?
stimulate secretion of mucous and bicarbonate, and they promote vasodilation, which helps maintain submucosal blood flow. They provide additional protection by suppressing secretion of gastric acid. Sensitize pain receptors (Why we take NSAIDs!).
What is the order do we order these classes of drugs in (antacids, H2RAs, and PPIs)?
Starting with antacids, progressing to H2 antagonists, and then prescribing PPIs when those aforementioned are ineffective.
Ensure to document what patients have tried prior to appointment to ensure insurance approval.
How should PPIs be discontinued?
Most PPIs should only be prescribed for 4-8wks. Should be tapered off over 2-4 weeks. Failure to taper can cause rebound acidity.
What is a major cause of PUD? How is it treated?
Helicobacter Pylori (H. pylori), a gram-negative bacillus, is one of the major causes of PUD. A multi-drug regimen is a proper treatment for H. pylori eradication.
**High antibiotic resistance rates can make it difficult to fully eradicate this infection.
What is the greatest risk associated with H. pylori?
Increased risk of gastric cancer
What is important for a prescriber to know when treating PUD/H. pylori?
The prescriber needs to understand local resistance patterns for prescribing. Resistance rates are increasing, and quadruple therapy is now required.
