* NaHCO3- systemic alkalosis, high Na- exacerbate HTN, HF, renal insufficiency * ALL- long term self-medication can mask symptoms of underlying disease like bleeding ulcer or malignancy * Interactions * Adsorption- antacid absorbs so less of other drug available for body * Chelation- chemical inactivation of other drugs that produces insoluble complexes * Inc stomach pH- inc absorption of basic drugs and dec absorption of acidic drugs * Inc urinary pH- inc excretion of acidic drugs and dec excretion of basic drugs * Quinolones!! – can reduce absorption by 50% * Drugs.
* MANY OTC * Preg ok- consult doc * Al- based for renal compromise- more easily excreted * CaCO3- can produce belching/gas- use w/ simethicone * Mg- laxative * Ca/Mg- accumulate to toxic levels in renal pts * Ca- r/f rebound hyperactidity, milk-alkali syndrome, changes in systemic pH- esp w/ renal dysfunction * H2 Receptor Antagonists * MOA * Competitively block H2 receptor of acid-producing parietal cells * Reduce H+ secretion f/ parietal cells inc in pH of stomach and relief of symptoms * Widely used- efficacy, OTC availability, excellent safety profile * Indications.
* GERD, PUD, erosive esophagitis * Stress ulcer prophylaxis * Adjunct: upper GI bleed, Zollinger-Ellison syndrome * Smoking decreases effectiveness * Contraindications * Relative: liver/kidney dysfunction- dosage adj * Adv * Elderly- confusion, AMS * Interactions * Smoking dec effectiveness * Take 1-2hr b4 antacid * Drugs * Cimetidine (Tagamet) * Largely replaced by other 2 * Treat certain allergic reactions only * Impotence/gynecomastia * Highest r/f interaction of 3- esp in elderly (Binds to P-450- warfarin, theophylline, lidocaine, phenytoin) * Not w/ antacid- 1hr apart * Take w/ meal.
* Ranitidine (Zantac) * Oral/IV * Baseline CMP- BUN, ALP, AST, ALTT, Creatinine, bili (renal/hepatic fx) * Rapid infusion=cardiac irregularities/HOTN- monitor BP! * Famatodine (Pepcid) * Oral, IV * Not w/ antacid- 1hr apart * Proton Pump Inhibitors * MOA * Bind irreversibly to proton pump * Prevents movement of H+ out of parietal cells and into stomach * Block 90% acid secretion over 24hr * Pts temporarily achlorhydric (w/o acid) * Food absorption not affected * Indications * First line- erosive esophagitis, GERD * Short-term- active duodenal ulcer, active benign gastric ulcer.
* Long-term- maintenance of healing of erosive esophagitis, Zollinger-Ellison, GERD * H. Pylori- combo w/ antibiotics * Give through NG tube or orally * Orally- swallow assessment- large pills!! * Contraindications * Adv * Possible osteoporosis * Overprescribed= predispose to GI tract infections b/c reduction of normal acid-mediated antimicrobial protection * Interactions * Take on empty stomach!! * Warfarin- inc bleeding * Inc serum levels of diazepam/phenytoin * Clopidogrel- inc r/f death in acute coronary syndrome * Drugs * Omeprazole (Prilosec) * 30min b4 meal * Only generic available.
* Don’t open/crush/chew * Lansoprazole (Prevacid) * Capsule, granules for oral suspension, oral disintegrating tabs * Capsules- mix w/ apple juice for NG tube; applesauce for granules * Pantoprazole (Protonix) * IV * Continuous infusion for GI bleed * Delayed release granules for NG * Must be 16g or larger or will clog tube * Miscellaneous Acid-Controlling Drugs * Drugs * Sucralfate (Carafate) * Mucosal protectant- binds directly to surface of ulcer * Active stress ulcerations * Long-term therapy PUD * Not used much due to QID dosing * Nausea, constipation, dry mouth * Empty stomach- 1hr before meals and QHS.
* Misoprostol (Cytotec) * Prostaglandin E analogue * NSAID’s- reduce r/f ulcers * Abortifacient- Preg X! * Used in such high doses= abd cramps, diarrhea * W/ food and QHS * Simethicone (Mylicon) * Reduce discomforts of gastric/intestinal gas * Alters elasticity of mucus-coated gas bubbles- breaks into smaller ones * Reduces gas pain and facilitated gas expulsion thru mouth/rectum * Oral- 6x/day * Can use w/ PPI * Nursing Process * Assessment * High sodium content= lead to exacerbation of cardiac probs, renal dysfunction, fluid-electrolyte probs * Implementation * Antacids- * give w/ 8oz water;
* recommend combo Al/Mg if constipation or diarrhea from only 1 product * Not w/in 1-2hr of other drugs * Overuse/misuse/rapid discontinuation= acid rebound! * Can promote dissolution of enteric coating of other meds * Renal probs- use Al-based! – more easily secreted * H2 * Smoking decreases effectiveness * Report prolonged HA Answer Keys – Case Studies * 1. Antacids have been found to have many side effects, such as constipation and diarrhea, and may also lead to rebound of hyperacidity, which may indeed increase the detrimental effects of acid on the reflux disease and on any ulcerated areas in the stomach.
Antacids elevate gastric pH, which is why they have been used in the past; however, antacids do not affect the gastric production of acid, which the other drugs (such as H2-blocking drugs) do so effectively. In addition, long-term self-treatment with antacids may actually delay needed therapy for certain conditions, such as Helicobacter pylori, or more serious conditions, such as gastric ulcers. * 2. Baseline renal and liver function should be evaluated.
In addition, the gastroenterologist will test for the presence of H.pylori antibodies. * 3. Proton pump inhibitors are used as long-term therapy to promote and maintain the healing of GERD and other hypersecretory disorders. The PPI inhibits the production of hydrochloric acid in the stomach. * 4. Omeprazole should be administered before meals, and the capsule should be taken whole and not crushed, opened, or chewed. It should be taken on an empty stomach, 30 to 60 minutes before breakfast, with a full glass of water. Answer Keys – Critical Thinking Activities 1.
Simethicone is used for its antiflatulent activity and because it helps to alter the elasticity of mucus-coated bubbles, causing the gastric bubbles to break, thus decreasing gas formation. It is hoped that this action will reduce the painful symptoms of gas. 2. Both calcium- and magnesium-based antacids are more likely to accumulate to toxic levels in patients with renal disease. Therefore, if antacids are used in renal patients, preparations that are aluminum-based should be chosen because they are generally more easily excreted than other categories of antacid.
Sodium-based antacids may cause fluid retention and metabolic changes; so they should be avoided as well. 3. Actually, antacids do not coat the stomach. They elevate the gastric pH so that the acidic environment, which could cause more problems for patients with ulcers, does not exist. In addition, elevating the gastric pH also helps to decrease the pain and discomfort of the gastric ulcer. Ch 51- Antidiarrheal/Laxatives * A/P & Disease Overview * Acute diarrhea * 3days-2wk * Self-limiting * Drugs, bacteria, viruses, protozoa, nutritional factors * Chronic diarrhea * 3-4wk.
* Possible fever, loss of appetite, N/V, weight reduction, chronic weakness * Tumors, AIDS, DM, hyperthyroidism, Addison’s, IBS * DON’T GIVE W/ bacterial or parasitic infection! – can cause organism to stay in body longer and prolong recovery * Overview * Antidiarrheals * MOA * Indications * Contraindications * Any major acute GI condition- intestinal obs, colitis * Adv * Interactions * Drugs * Adsorbents * Coat walls of GI tract * Bind to bacterial or toxin to their absorbent surface for elimination thru stool * Mild cases * Interaction- dig, warfarin, clindamycin, quinidine, hypoglycemic drugs * Drugs.
* Bismuth subsalicylate (Pepto-Bismol) * Form of aspirin * Caution- children; teenagers that have or recovering f/ chickenpox or flu * Reyes! * Alarming but harmless adv=temporary darkening of tongue and black/gray stool * Warfarin, NSAID, aspirin- inc bleeding * Confusion in elderly * Activated charcoal * Overdoses- drug binding * Anticholinergics * Slow peristalsis- reduce rhythmic contractions and smooth muscle tone of GI tract * Combo w/ adsorbents/opiates * Severe cases * No antacids, other anticholinergics (amantadine, MAOI, tricyclic antidepressants) * Drugs-.
* BELLADONNA ALKALOIDS * Narrow therapeutic index * Combo of Atropine, Hyoscyamine, Phenobarbital, Scopolamine * Elixir, tabs, ER tabs * Preg C-X * Opiates * Reduce bowel motility * Dec pain f/ rectal spasms * Severe cases * No other CNS depressants! * Drugs * Diphenoxylate w/ atropine (Lomotil, Lonox) * Synthetic opioid agonist * Smooth muscle of intestinal tract- * Little or no analgesic activity- still can develop dependence!! * Watch resp depression! * Contra- pseudomembranous colitis or toxigenic bacteria * Loperaminde (Imodium AD) * Only OTC opioid.
* No dependence reported * Elderly- watch electrolyte depletion! * Contra- UC, pseudomembranous colitis, acute diarrhea f/ E. Coli * Intestinal Flora Modifiers- probiotics/bacterial replacement drugs * Obtained f/ bacterial cultures- Lactobacillus- majority of body’s normal flora * Commonly destroyed by antibiotics- restore the flora Suppress growth of diarrhea-causing bacteria * Through fermentation of carbs they create unfavorable environment for overgrowth of harmful fungi/bacteria * Drugs * Lactobacillus acidophilus/Lactobacillus GG * Uncomplicated diarrhea.
* Laxatives * MOA * Indications * Contraindications * Caution: acute surgical abdomen, appendicitis symptoms (N/V, abd pain), fecal impaction (except mineral oil), intestinal obs, undiagnosed abd pain * Adv * Interactions * Drugs * Bulk-forming * Absorb water into intestine increases bulk and distends bowel to initiate reflex bowel activity promoting bowel movement * Only one that can be used long term * Take w/ H2O to prevent esophageal obs/fecal impaction * Interaction: dec absorption of antibiotics, dig, salicylates, warfarin * Drugs * Methycellulose.
* Synthetic bulk-forming * Contra- GI obs, hepatitis * Powder- 2g fiber/tsp * 8oz H2O- drink immediately to avoid choking * Psyllium * Natural bulk-forming * Contra- intestinal obs, fecal impaction, abd pain, N/V * Oral- wafer/powder * Emollient (Stool softeners/lubricant laxatives) * Stool Softener- lowers surface tension of GI fluids so that more H2O and fat are absorbed into stool and intestines * Lubricant- lubricates fecal material and intestinal wall preventing absorption of water from intestines H2O then softens bowel and expands stool defecation * Drugs.
* Ducosate salts (Colace) * Ca & Na * Don’t cause pts to defecate- only soften to ease passage * Contra- intestinal obs, fecal impaction, N/V * Mineral oil (Kondremul plain) * Lubricant * Dec absorption of vitamins A,D,E,K * Contra- intestinal obs, fecal impaction, N/V * Hyperosmotic * Increase fecal water content distention/peristalsis/evacuation * Large intestine only * Interaction: barbs, gen anesth, opioids, antipsychotics- inc CNS depression * Drugs * Glycerin (Fleet Babylax) * Mild- used in children * Lactulose.
* Colonic bacteria digest and form acids create hyperosmotic/laxative effect * Reduces blood ammonia by converting ammonia to ammonium * Hepatic encephalopathy * Baseline mental status/ammonia levels * Take w/ juice, milk, water for taste * Normal color= pale yellow * Polyethylene glycol 3350 * Diagnostic/surgical bowel procedure- total cleansing of bowel * Reconstituted in 1 GAL, drank afternoon of day before procedure * GI Lavage- diarrhea in 30-60min * Contra- GI obs, gastric retention, bowel perforation, toxic colitis, toxic megacolon, ileus * Miralax- smaller dosages for constipation- OTC * Saline.
* Increase osmotic pressure in the small intestine by inhibiting water absorption and inc both H2O and electrolyte secretions f/ bowel wall into bowel lumen watery stool * NaPO4 enema=defecation in 2-5min * Drugs * Magnesium salts * Caution in renal sufficiency-hypermagnesia * Endoscopic sx- rapid removal * Remove unabsorbed poisons * Contra- renal disease, abd pain, N/V, obs, sx, rectal bleeding * * Stimulant * Stimulate nerves that innervate the intestines inc peristalsis * Inc fluid to colon inc bulk and softens stool * Interaction: dec absorption of antibiotics, dig, salicylates, oral coags * Drugs.
* Bisacodyl (Dulcolax) * Constipation * Endoscopic sx- whole bowel evacuation * Empty stomach for faster absorption * No milk, antacids, juice w/in 1 hr of dose * Oral, suppository * Senna (Senokot) * Acute constipation * Sx, exam prep- complete bowel evac in 6-12hr * Can cause abd pain- stimulates GI tract * Turn urine pink/red/brown * 6-12hr for laxative effects * Syrup, tabs, granules * IBS * Tegaserod * Adv- HA, angina, stroke * Must register w/ manufacturer * Baseline cardiac/hepatic function * Lubiprostone (Amitiza) * Chloride channel activator.
* Idiopathic constipation- women >18yr * Contra- obs * Nursing Process * Assessment * Bowel sounds: hypoactive (2yr * Transient taste disorder w/ antineoplastic meds- will pass w/ continued therapy * Tetrahhydrocannabinoid (THC derivative) * Inhibitory effects on reticular formation, thalamus, cerebral cortex * Dronabinol * 2nd-line * Aids, Cancer N/V * Nutritional wasting syndrome- inc appetite * Control glaucoma * Chemo- take 1-3hr b4 treatment * Move slowly- orthoHOTN * Misc * Phosphorated carbohydrate solution * Mint-flavored.
* Reduces cramping caused by excessive smooth muscle contraction * MILD CASES ONLY- flu, excessive unhealthy eating/druking * Morning sickness * Aprepitant * P-neurokin 1 receptor antagonist * Highly emetogenic chemo * Inc warfarin- measure INR b4 each dose * Nursing Process * Assessment * Implementation * CHEMO- ondansetron, granisetron, dronabinol * Evaluation Answer Keys – Case Studies 1. Granisetron works by blocking the serotonin that increases with chemotherapy and so blocks the 5-HT3 receptors in the GI tract, the chemoreceptor trigger zone (CTZ), and the vomiting center in the medulla.
2. Patient teaching for ondansetron (Zofran) includes the following: * Take the medication as ordered. * Make sure to follow the instructions for premedication for chemotherapy. * Take the medication for up to 2 weeks after the specific chemotherapy treatment to maximize the antiemetic properties. * Observe for signs of dehydration, and report to the physician immediately if these occur. * Avoid alcohol and other CNS depressants during this therapy, and avoid activities that require mental alertness or motor skills because of the drowsiness that may result. 3.
Dronabinol is most often used in patients who are undergoing chemotherapy and experiencing the attendant nausea and vomiting. Dronabinol is a commercially available THC and is a synthetic derivative of the major active substance in marijuana. Dronabinol was approved by the FDA in 1985 for the treatment of nausea and vomiting related to cancer chemotherapy. It is typically used as a second-line drug after treatment with other antiemetics has not been effective. It affects the vomiting center and decreases the nausea and vomiting resulting from cancer chemotherapy.
He should be told that even though this medication is derived from marijuana, the dosage used in dronabinol will not make him “high” and has been effective in the management of nausea and vomiting associated with chemotherapy. Answer Keys – Critical Thinking Activities Chapter 52: Antiemetic and Antinausea Drugs 1. Ondansetron hydrochloride (Zofran) is specifically indicated for the prevention of nausea and vomiting related to the administration of chemotherapy because it blocks serotonin peripherally (in the GI tract) and centrally (in the chemoreceptor trigger zone [CTZ] and vomiting center [VC]).
Chemotherapy causes nausea and vomiting because of the toxic effects on the CTZ and stimulation of the 5-HT3 receptors (serotonin receptors). Ondansetron works better because of its multiple sites of action to prevent the release of serotonin, whereas prochlorperazine acts only centrally by blocking the CTZ and the vomiting center to help prevent nausea and vomiting. In addition, because ondansetron acts specifically against the serotonin receptors, it has fewer adverse effects, which is another benefit. Ondansetron works better to prevent nausea when administered 30 to 60 minutes before the chemotherapy is started.
2. A thorough assessment of hydration status is important because, in addition to reducing nausea and vomiting, there may be a need for treatment of volume and electrolyte imbalances. 3. Dizziness, drowsiness, confusion, and hypotension may be of concern in patients, especially the elderly, who are taking antinausea or antiemetic medications. Special attention to fall and injury prevention is important. Of course, the nurse also needs to monitor for the intended therapeutic effect of reducing the patient’s nausea.