GASTROINTESTINAL MEDICATIONS By: Jerald S. Ugdoracion, RN, MN-MS

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1 GASTROINTESTINAL MEDICATIONS By: Jerald S. Ugdoracion, RN, MN-MS Reviewing these things may help you in understanding better how gastrointestinal medications alleviate problems of the GI tract: a. Review of the Anatomy and Physiology of the Gastrointestinal system b. Mechanism of Peptic Ulcer formation Common Classification of Gastrointestinal medications: 1. Anti-ulcer medications 2. Anti-diarrheal medications 3. Laxatives 4. Anti-emetic and Emetic drugs 5. Adsorbent, anti-flatulent and digestive drugs MUST KNOWS: ANTI-ULCER DRUGS A peptic ulcer is a circumscribed lesion in the mucosal membrane, developing in any part of the alimentary canal (e.g. esophagus, duodenum, stomach, jejunum.. etc) The common causes of peptic ulcer development includes: a. Helicobacter pylori b. NSAID use c. Hypersecretory states ( e.g. Zollinger- Ellison Syndrome) d. Cigarette smoking e. Genetic predisposition What are the common anti-ulcer medications? a. Systemic antibiotics b. Antacids c. histamine 2 receptor antagonists d. proton-pump inhibitors e. other medications like sucralfate and misoprostol A. SYSTEMIC ANTIBIOTICS Systemic antibiotics aim to reduce the recurrence of peptic ulcers and promote healing through eradicating one of the most common causative agent of peptic ulcer disease Helicobacter pylori. Prototype medications: a. Amoxicillin b. Clarithromycin c. Metronidazole d. Tetracycline Note: systemic antibiotics are usually given in combination doses. Systemic antibiotics are given in pair to come up with better results. Systemic antibiotic acts by treating H. Pylori infection and is usually given in combination doses and is paired with other anti-ulcer medications like H2 receptor antagonists or Proton pump inhibitors Nursing Responsibilities: 1. Take note of various drug to drug interactions: a. Tetracycline increases digoxin levels in the body b. Tetracycline and Metronidazole can increase bleeding tendencies if given together with anticoagulants 2. Take note of various side effects of the medications: a. Clarithromycin and Metronidazole can cause abnormal tastes and may affect appetite b. Do not give Metronidazole together with alcohol containing substances- disulferam like effects c. Metronidazole can cause sodium retention 3. Assess the patient s infection before therapy and regularly thereafter 4. Assess signs of recovery of patient s ulcer 5. Administer drugs as appropriate for the patient s condition 6. Instruct patient to follow pharmacologic regimen religiously, especially when dealing with antibiotics 7. Avoid giving the medication with dairy products as these may decrease drug absorption 8. Take note that antibiotics are highly nephrotoxic

2 B. ANTACIDS These are OTC medications that are used to treat peptic ulcers. These are also known to be effective in relieving symptoms of dyspepsia, heartburn and GERD Prototype Medications: 1. Aluminum Carbonate 2. Calcium Carbonate 3. Magaldrate (Aluminum-Magnesium Complex) 4. Magnesium hydroxide 5. Aluminum Hydroxide 6. Simethicone Antacids work by neutralizing the acidity in the alimentary tract thus reducing Pepsin activity, allowing peptic ulcers time to heal. Note: Calcium containing antacids may stop the development of hyperphosphatemia as calcium salts combine with phosphorus. This leads to the direct elimination of the phosphorus without being absorbed in the body. Antacids may reduce the absorption of oral medications 1. Constipation 2. Diarrhea 3. Electrolyte imbalances 4. Aluminum accumulation in the serum Nursing responsibilities: 1. Give other oral medications two hours prior to giving of antacids 2. Take note of side effect and address it 3. Record the number and consistency of stools 4. Take not of fluid and electrolyte imbalances among clients in long term therapy of aluminium containing antacids 5. Watch out for electrolyte imbalances 6. Manage constipation with laxatives or stool softeners; other type of antacids may be prescribed 7. manage diarrhea with anti-diarrheals as needed; a change in the antacid may be prescribed 8. Avoid taking calcium containing antacids with calcium and vitamin D rich foods 9. Don t take sodium bicarbonate with milk 10. Inform client that aluminium hydroxide may cause a whitish discoloration of the feces 11. Increase fluid intake and roughage on diet for clients taking aluminium containing antacids C. H2-RECEPTOR ANTAGONIST Given to promote healing of duodenal and gastric ulcers; given for long term treatment of hypersecretory conditions. Prototype medications: 1. famotidine 2. Ranitidine 3. Cimetidine 4. Nizatidine Block the histamine receptor sites in the parietal cells leading to the decrease in the gastric acid secretion in the stomach. Drug to 1. Antacids decrease the absorption of these medications 2. Cimetidine increases the blood levels of cardiac medication like anticoagulants, antihypertensives like beta blockers, calcium channel bockers, anti-arrythmics and other neuromuscular medications like carbamazepine and phenytoin. 3. Cimetiidne may inhibit ethyl alcohol metabolism in the stomach resulting in higher blood alcohol levels Nursing responsibilities: 1. Administer once daily dose at bed time and if twice daily dose in the morning and in the evening. Multiple doses, with meals and at bedtime. 2. Administer antacids 1 hour before or after giving H2 receptor antagonists 3. Monitor cardiovascular status for clients receiving continuous IV infusions of H2 receptor antagonists. 4. Avoid stopping abruptly 5. Anticipate dosage adjustments for clients with renal diseases 6. Take the drug with snacks if desired Avoid taking the medication for more than 8 weeks or unless prescribed by physician

3 D. PROTON PUMP INHIBITORS Proton pump inhibitors disrupt chemical binding in stomach cells to reduce acid production, lessening irritation and allowing peptic ulcers to better heal. Usually given for short term treatment of gastric ulcers, active duodenal ulcers, erosive esophagitis, symptomatic GERD and long term treatment of hypersecretory states. Prototype Medications: 1. Esomeprazole 2. Lansoprazole 3. Omeprazole 4. Pantoprazole 5. Rabeprazole Proton pump inhibitors block the last step in gastric acid secretion by combining with hydrogen, potassium and adenosine triphosphate in the parietal cells of the stomach. Note: These medications are given orally in enteric-coated formulas to bypass the stomach because they are highly unstable in an acidic environment. They dissolve in the small intestine and are rapidly absorbed. Adverse Reactions: 1. Abdominal pain 2. Diarrhea 3. Nausea and Vomiting Nursing responsibilities: 1. Monitor the patient s hydration status if severe GI side effects occur 2. Administer the drugs 30 minutes before meals 3. Dosage adjustments aren t needed for clients with hepatic and renal dysfunction 4. Tell patient to swallow medications whole and avoid crushing medications 5. oral pantoprazole may be given with or without food 6. If swallowing capsules is difficult, lansoprazole may be opened and mixed with 60ml of liquid solution like juices 7. Avoid taking OTC medications without consulting to prescriber E. OTHER ANTI-ULCER MEDICATIONS Two known anti-ulcer medications are: 1. Misoprostol (Cytotec) 2. Sucralfate MISOPROSTOL This medication is not as potent as other anti-ulcer medications but is given for prevention of gastric ulcer formation usually caused by NSAID use. Must know! This medication is a PREGNANCY CATEGORY X medication and should not be given to pregnant women as this may cause abortion. It reduces the secretion of gastric acid and promotes increase gastric mucus production that may lead to better protection. Adverse effects a. diarrhea b. abdominal pain c. gas d. indigestion e. nausea and vomiting f. spontaneous abortion Nursing responsibilities: 1. If client is female, a pregnancy test may be done prior to misoprostol therapy 2. Monitor fluid and electrolyte status if adverse GI effects occur 3. Administer misoprostol with food SUCRALFATE This medication is used for short treatment (up to 8 weeks) for gastric and duodenal ulcers and prevention of recurrent stress ulcers. Pharmacodynamics This works locally in the stomach, reacting with hydrochloric acid to form a thick, pastelike substance that adheres to the gastric mucosa and especially to ulcers. Adverse Effects: a. Constipation b. Metallic taste c. Nausea and Vomiting

4 Nursing Responsibilities: 1. Administer sucralfate 1 hour prior meals and at bed time 2. Dissolve medication in a glass of water before consumption COMMON HEALTH TEACHING WHEN GIVING ANTI- ULCER MEDICATIONS: 1. Elevate the head of the bed 2. Avoid abdominal distension by eating heavy meals. Small frequent feedings may do the trick 3. Avoid lying down 1 or 2 hours after eating 4. Avoid intake of foods that can increase gastric acid secretion like alcohol, coffee, citrus juices and chocolate 5. Avoid cigarette smoking 6. Swallow medications as directed. Some medications are enteric coated in nature 7. Avoid gastric irritants like spicy foods and NSAID use 8. Employ stress management techniques 9. Avoid taking OTC medications unless consulted to prescriber. ANTI-DIARRHEAL DRUGS Antidiarrheals prevent excessive defecation. They act systemically or locally. This includes: a. Opioid-related drugs b. Kaolin and Pectin A. OPIOID-RELATED DRUGS Opioid related drugs reduce peristalsis in the intestines. Prototype Medications: a. Diphenoxylate with atropine b. Loperamide Pharmacodyanmics: They slow the peristaltic movement of the intestines by decreasing the circular and longitudinal muscles of the intestine. Enhance the depressant effects of barbiturates, alcohol, opoids, tranquilizers and sedatives. Note: Avoid giving opioid related medications frequently and in high doses. Dependence and respiratory depression is a common side effect B. KAOLIN and PECTIN Kaolin and Pectin mixtures are locally acting OTC antidiarrheals. They work by absorbing irritants and soothing the intestinal mucosa. They act as adsorbents, binding to bacteria and toxins and other irritants in the intestinal mucosa Adverse Reactions: a. Constipation is common among elderly and debilitated patients NURSING INTERVENTIONS WHEN GIVING ANTI- DIARRHEALS 1. Assess the patients diarrhea before and regularly there after 2. Monitor fluid and electrolyte balance and correct any imbalance if present 3. Monitor hydration status if severe GI upset occurs 4. Use naloxone to treat respiratory depression associated with opioid related drugs 5. Take safety precautions as CNS depression is a common side effect 6. Maintain intake of fluids and electrolytes up to 2 to 3 liters a day 7. Avoid foods or other gastric irritants that may cause further diarrhea LAXATIVES Laxatives stimulate defecation and include: a. Hyperosmolar laxatives b. Dietary fiber and Bulk-forming substances c. Emollients

5 d. Stimulants e. Lubricants A. HYPEROSMOLAR LAXATIVES Hyperosmolar laxatives work by drawing water into the intestine, thereby promoting bowel distention and peristalsis. Frequently used in: a. bowel retraining b. treatment for constipation c. complete bowel evacuation Prototype medications: a. Glycerin b. lactulose c. Magnesium salts d. Sodium biphosphate e. Sodium phosphate f. Polythylene glycol (PEG) Most of these medications are poorly absorbed systemically. They remain in the intestines where they promote their hyperosmolar effect, thus promoting persitalsis. They produce bowel movement by drawing water into the intestines. Fluid accumulation distends the intestines leading to increased peristaltic movement. Adverse effects: a. Fluid and Electrolyte Imbalances a.1. Hypokalemia a.2. Hypernatremia a.3. Hypeprmagnesemia a.4. Hyperphosphatemia a.5. Hypercalcemia b. Weakness and fatigue c. cardiac arrhythmias d. shock and hypovolemia e. diarrhea B. DIETARY FIBER and BULK-FORMING LAXATIVES Bulk-forming laxatives which resemble dietary fiber, contain natural and semisynthetic polysaccharides and cellulose. They are used to: a. treat constipation b. aid patients where straining is not allowed c. aid patients with Irritable Bowel Syndrome Prototype medications: a. Methylcellulose b. Polycarbophil c. Psyllium hydrophilic mucilloid They increase stool mass and water content, promoting peristalsis. Drug Interactons: a. decreases the absorption of digoxin, warfarin and salicylates a. feelings of fullness b. flatulence c. intestinal obstruction d. fecal impaction C. EMOLIENT LAXATIVES These medications are also known as stool softeners. They are the drug of choice for softening the stools of clients who are not allowed to perform straining like: a. recent MI or surgery b. diseases in the anus or rectum c. clients with increased ICP d. hernias e. aneurysms They emulsify the fat and water components in the feces in the small and large intestines. This allows fats and water to penetrate the stool, making it softer and easier to evacuate. They are also known to stimulate electrolyte and fluid secretion from mucosal cells in the intestines. If mineral oil is taken together with emollient laxatives, mineral oil becomes systemically absorbed Emolient laxatives may enhance the absorption of many oral medications, Drugs with low margin of safety must be administered with precaution.

6 a. bitter taste b. diarrhea c. throat irritation d. abdominal cramping D. STIMULANT LAXATIVES These are also known as irritant cathartics. They are commonly used and preferred for emptying the bowel before surgery or other diagnostic procedures requiring the bowel to be clean. They are also indicated for treatment of constipation. Prototype medications: a. Bisacodyl b. Cascara sagrada c. Castor oil d. Senna They stimulate peristalsis and produce bowel movement by irritating the intestinal mucosa or stimulating nerve endings of the intestinal smooth muscle. a. weakness b. nausea c. abdominal cramps d. mild inflammation of the anus or rectum e. urine discoloration (with senna or cascara sagrada use) E. LUBRICANT LAXATIVES Mineral oil is the main lubricant laxative n current clinical use. It is used to: a. treat constipation b. maintain soft stools when sraining is not allowed c. treat fecal impaction It lubricates the stool and the intestinal mucosa and prevents water reabsorption from the bowel lumen. The increased fluid content of feces increases peristalsis. a. nausea and vomiting b. abdominal cramping c. diarrhea To minimize drug interactions, administer mineral oil at least 2 hours before other drugs. a. Absorption of many oral drugs are decreased especially those that are fatsoluble and highly steroid bound. b. Mineral oil may interfere the activity of non-absorbable sulphonamides NURSING INTERVENTIONS WHEN GIVING LAXATIVES: 1. Time drug administration so that bowel evacuation will not interfere with activities of daily living 2. make sure that patient has easy access to bedpan or to comfort room 3. When giving rectal suppositories, avoid embedding medication to fecal material. Place it as deep as possible and against the walls of the rectum 4. Don t crush enteric coated tablets 5.Shake suspensions well and give with large volume of water 6. Therapy should be short term. Long term use can cause nutritional imbalances 7. Diet, exercise and fluid intake must be emphasized 8. Drink at least 8 to 10 glasses of water daily 9. Stool softeners and bulk-forming laxatives may take several days o take effect 10. If using bulk-forming laxatives, remain active and increase fluid intake 11. Stimulant laxatives may cause harmless urine discoloration 12. Increase fiber in food intake 13. Frequent and prolonged use of laxatives may result to independence 14. never take laxatives if abdominal pain is present, a ruptured appendix or other serious complication may result ANTI-EMETIC AND EMETICS Anti-emetics and emetics represent two groups of drugs with opposing actions. Emetic drugs produce vomiting while anti-emetic drugs decrease nausea, reducing urge to vomit.

7 A. ANTI-EMETICS Many of these medications, specifically the antihistamines are given for nausea and vomiting caused by inner ear disturbances. As a consequence, these drugs are used o prevent motion sickness. They are more effective if given before activities that promote motion sickness. Phenothiazines are usually given in situations where vomiting becomes severe and potentially hazardous such as post-surgical or viral nausea and vomiting or from cancer chemotherapy or radiotherapy. Prototype Medications: a. Antihistamines a.1. dimenhydrinate a.2. diphenhydramine hydrochloride a.3. buclizine hydrochloride a.4. cyclizine hydrochloride a.5. hydroxyzine hydrochloride a.6. meclizine hydrochloride a.6. trimethobenzamide hydrochloride b. Phenothiazines b.1. chlorpromazine hydrochloride b.2. perphenazine b.3. prochlorperazine maleate b.4. promethazine hydrochloride b.5. triethylperazine maleate c. Scopolamine d. Metoclopramide e. Dronabinol f. Ondansetron the DOC They produce their antiemetic effect by blocking the dopaminergic receptors in the chemoreceptor trigger zone in the brain Note: Scopolamine : is seldom used as an anti-emetic because of its sedative and anti-cholinergic effects. But scopolamine transdermal preparations Transderm-Scop, is highly effective without producing its associated adverse effects Dronabinol: an anti-emetic that is a purified derivative of cannabis and is a schedule II drug (meaning it has a high potential for abuse and tolerance) a. Antihistamines and phenothiazines can produce additive CNS depression and sedation when taken with CNS depressants such as barbiturates, tranquilizers, anti-depressants, alcohol and opioids b. Antihistamines can produce anticholinergic effects such as constipation, dry mouth, vision problems and urine retention c. Phenothiazines if given with Droperidol increases the risk of extrapyramidal symptoms a. drowsiness b. paradoxical CNS stimulation c. CNS depression like confusion, anxiety, depression, insomnia and headache d. Anti-cholinergic effects : constipation, dry mouth, difficult urination, impotence and visual and auditory disturbance NURSING RESPONSIBILITIES WHEN GIVING ANTI- EMETICS: 1. Monitor patient for CNS depression and anticholinergic effects 2. Give IM injections deeply in the muscles 3. Don t give anti-emetics subcutaneously 4. If the drug is given to prevent motion sickness, the patient should take the medication minutes before the activity 5. Warn the patient to avoid alcohol and other hazardous activities until the drug s CNS activities are known B. EMETICS Emetics are used to induce vomiting in a person who has ingested toxic substances. Prototype medication: Syrup of Ipecac Note: The use of syrup of ipecac has been controversial, however, because it delays the use of activated charcoal. In addition, there s a risk of potential abuse by individuals with eating disorders. The American Academy of Pediatrics no longer recommends giving syrup of ipecac to pediatric patients. It induces vomiting by stimulating the vomiting center located in the brain s medulla. After administration, vomiting occurs within 10 to 30 minutes

8 Note: success of treatment is directly linked to fluid intake with ipecac administration. Syrup of ipecac is only used to patients who are FULLY CONSCIOUS. Loss of fluid and electrolyte due to excessive vomiting NURSING RESPONSIBILITIES WHEN GIVING EMETICS: 1. Administer the drug exactly as directed 2. Do not administer if: a. patient ingested petroleum distillates like kerosene and gasoline or volatile oils b. patient ingested caustic substances such as lye 3. Administer 200 to 300 ml of water after giving a dose 4. If two doses do not promote vomiting, prepare for a gastric lavage 5. Position the position to his side to prevent aspiration during episodes of vomiting 6. Advise the provider or guardian to consult the prescriber or poison control center before giving ipecac to child ASORBENT, ANTI-FLATULENT AND DIGESTIVE DRUGS A. ADSORBENT DRUGS Natural and sunthetic adsorbent drugs, or adsorbents, are prescribed as antidotes for the ingestion of toxins, substances that can lead to poisoning or overdose. The most commonly used clinical adsorbent is activated charcoal, a black powder residue obtained from the distillation of various organic materials. Activated Charcoal is a general purpose antidote used for many types of acute oral poisoning. It isn t indicated in acute poisoning from mineral acids, alkalines, cyanide, ethanol, methanol, iron, sodium chloride alkali, inorganic acids or organic solvents. It also shouldn t be used in children younger than age 1. It shouldn t be used if the patients has a risk of GI obstruction, perforation, or hemorrhage; decreased or absent bowel sounds; or a history of recent GI surgery. Because adsorbent drugs attract and bind toxins in the intestine, they inhibit toxins from being adsorbed from the GI tract. However, this binding doesn t change toxic effects caused by earlier absorption of the poison. Drugs used to induce vomiting, such as ipecac syrup, may decrease the effectiveness of activated charcoal. If these drugs are used together to treat oral poisoning, activated charcoal should be used only after vomiting has stopped. Activated charcoal turns stool black and may cause constipation. A laxative, such as sorbitol, is usually given with activated charcoal to prevent constipation and improve taste. NURSING RESPONSIBILITIES WHEN GIVING ADSORBENTS: 1. Don t give the drug to a semiconscious or unconscious patient unless the airway is protected and an NG tube is in place for instillation. 2. Mix the powdered form with tap water to form the consistency of thick syrup. Add a small amount of fruit juice or flavouring to make it more palatable. 3. Give by NG tube after lavage, if needed. 4. Don t give the drug in ice cream, milk, or sherbet, which may reduce absorption. 5. Repeat the dose if the patient vomits shortly after administration. 6. Keep airway, oxygen, and suction equipment nearby. 7. Follow treatment with a stool softener or laxative to prevent constipation. 8. Tell the patient that his stools will be black. B. ANTIFLATULENT DRUGS Antiflatulent drugs, or antiflatulents, disperse gas pockets in the GI tract. They are available alone or in

9 combination with antacids. The major antiflatulent drug currently in use is simethicone. Simethicone is prescribed to treat conditions in which excess gas is a problem, such as: Functional gastric bloating Postoperative gaseous bloating Diverticular disease Spastic or irritable colon The swallowing of air Simethicone creates foaming action in the GI tract. It produces a film in the intestines that disperses mucus-enclosed gas pockets and helps prevent their formation. Simethicone doesn t interact significantly with other drugs. Simethicone doesn t cause any know adverse reactions. It has, however, been associated with excessive belching or flatus. NURSING RESPONSIBILITIES WHEN GIVING ANTIFLATULENTS: 1. Make sure that the patient chews the tablet form before swallowing. 2. If giving the suspension form, make sure to shake the bottle or container thoroughly to distribute the solution. 3. Inform the patient that the drug doesn t prevent gas formation. 4. Encourage the patient to change his position frequently and to ambulate to help pass flatus. C. DIGESTIVE DRUGS Digestive drugs (also called digestants) aid digestion in patients who are missing enzymes or other substances needed to digest food. Digestive drugs that function in the GI tract, liver, and pancreas include: Dehydrocholic acid Pancreatin, pancrelipase, lipase, protease, and amylase (pancreatic enzymes) Pancreatic enzymes are administered to patients with insufficient levels of pancreatic enzymes, such as those with pancreatitis or cystic fibrosis. They may also be used to treat steatorrhea ( a disorder of fat metabolism characterized by fatty, foul-smelling stools). The action of digestive drugs resembles the action of the body substances they replace. Dehydrocholic acid, a bile acid, increases the output of bile in the liver. The pancreatic enzymes replace normal pancreatic enzymes. They exert their effect in the duodenum and upper jejunum of the upper GI tract. Antacids reduce the effects of pancreatic enzymes and shouldn t be given at the same time. Pancreatic enzymes may also decrease the absorption of folic acid and iron. Adverse reactions to dehydrocholic acid include: Abdominal cramping Biliary colic (with gallstone obstruction of the biliary duct) Diarrhea Adverse reactions to pancreatic enzymes include: Diarrhea Nausea Abdominal cramping NURSING RESPONSIBILITIES WHEN GIVING DIGESTANTS: 1. Administer the drug before or with each meal, as applicable. 2. For infants, the powdered form may be mixed with applesauce and given before meals. 3. Avoid contact with or inhalation of the powder form; it may be irritating. 4. Older children may take capsule with food. 5. Tell the patient not to crush or chew entericcoated dosage forms. Capsules containing entericcoated microspheres may be opened and their contents sprinkled on a small amount of soft food,

10 such as applesauce. Follow administration with a glass of water or juice. 6. Review food preferences and diet orders witht he patient and his family. 7. provide food and fluids that the patient enjoys at times he prefers, if possible. 8. Treat symptoms or disorders that may interfere with nutrition, such as pain, nausea, vomiting, or diarrhea. 9. Consult with a dietician if special diets are ordered. Provide foods the patient likes that are nutritionally better choices but are within the prescribed diet. Prepared by: Jerald S. Ugdoracion, RN, MN (please do not reproduce without permission)