GI Meds Chapters 40 and 42

What is Important About GI Meds? Objectives: Know conditions used for Know goals for treatment Identify classification of medications

What is Important About GI Meds? (continued) Understand nursing process for administration of prototype drugs used for: –GERD –Ulcers –IBS –Constipation –Diarrhea –Nausea –Pancreatic disorders

Chapter 40: Peptic Ulcer Disease and GERD

GERD Acidic contents move up esophagus Usually due to a weakening of the lower esophogeal spincter (LES) Treated by elevating HOB, weight loss, avoiding smoking, small meals, and eliminating smoking and ETOH

Peptic Ulcer Disease Erosion of the mucosa layer of the GI tract Associated with inflammation, pain and bleeding Two types: –Peptic Ulcer (in stomach) –Duodenal Ulcer (in small intestine)

Primary Cause of PUD Helicobacter pylori –Associated with 80% duodenal and 70% gastric –Gram negative bacterium NSAIDS –Cause direct cellular damage –Decrease secretion of protective mucus and bicarbonate ion

Pharmacological Management of GERD 1. Antacids 2.H2-receptor blockers (antagonists) 3. Proton pump inhibitors (PPIs) 4.Combination antibiotic therapy 5.Sucralfate (Carafate)

1. Antacids

Common Antacids Aluminum hydroxide (AlternaGEL) Magnesium hydroxide (MOM) Calcium (Tums) Sodium bicarbonate

What’s Important About Antacids? Work by neutralizing gastric acids Aluminum and calcium cause constipation –i.e., Maalox and Tums Magnesium causes diarrhea –i.e., MOM Alternate these to offset adverse effects

What’s Important about Antacids? Sodium containing antacids result in fluid retention –Caution with CHF and HTN Magnesium containing can lead to toxicity with renal impairment Aluminum binds to warfarin and tetracycline and inhibits absorption

2. H2 Receptor Blockers

H2 Receptor Blockers H2 receptors are responsible for increasing acid secretion in the stomach H2 blockers (antagonists) suppress the volume and acidity of parietal cell secretions from H2 receptors

What’s Important About H2 Blockers? ***Smoking decreases absorption Caution with renal or hepatic disease Do not take with antacids, it can inhibit H2 blocker absorption ***Chronic suppression of acid can decrease vitamin B-12 absorption resulting in anemia

3. PPIs Omeprazole

What Is Important About PPIs? Reduce acid secretion by binding to H+, K+ and ATPase Reduce acid secretion more effectively than H2 Blockers and have a longer duration Take 20 – 30 minutes before meals

What Is Important About PPIs? Increase risk of osteoporosis and cancer (do not take long term) May increase Digoxin (Lanoxin) levels May increase risk for pneumonia through lowering pH and thus promoting bacteria colonization of the stomach and respiratory tract

4. Combination Therapy For H. Pylori

What’s Important About Combination Therapy? Treating H. Pylori with two antibiotics –Increases effectiveness –Decreases bacterial resistance Some combinations include Pepto Bismol due to bacterial growth inhibition –Pepto Bismol turns stools black –Pepto Bismol also used for diarrhea

5. What Is Important About Sucralfate (Carafate)? Sucralfate works by dissolving into a gel and adhering to the site of the ulcer, not by decreasing stomach acid, not by inhibiting bacterial growth, nor by neutralizing stomach acid.

Chapter 41: Bowel and Other GI Conditions

Prevention of Constipation How do you teach your patient to prevent and treat constipation?

Medications For Constipation Laxatives Classes 1.Bulk Forming 2.Saline and Osmotic 3.Stimulant 4.Stool Softener/Surfactant 5.Herbal Agent

1. What Is Important About Bulk Forming Laxatives? Prototype: psyllium mucilloid (Metamucil) –Fiber substance absorbs water –Increases fecal mass –Slow onset of action (1-3 days) –Must be taken with plenty of water Insufficient water = esophageal obstruction –Can decrease absorption of digoxin, warfarin, antibiotics and others

2. What Is Important About Saline and Osmotic Laxatives? Prototype: polyethylene glycol (MiraLax) Do not absorb in the intestine – pulls water and make a more watery stool Work quickly May cause dehydration and F and E imbalance Colonoscopy prep Avoid with sodium if heart disease

3. What is Important About Stimulant Laxatives? Prototype: bisacodyl (Ducolax) Promote peristalsis by irritating bowel mucosa Can cause cramping, urgency, fluid loss May cause laxative dependence

4. What Is Important About Stool Softeners? Prototype: docusate (Colace) Works by causing more fat and water to be absorbed Used often as prevention of constipation post op, in elderly, cardiac patients to prevent straining Very commonly given Know difference between stool softener and stimulant laxative to explain to patient

5. Herbal Agents and Misc. Mineral oil –Lubricates stool and colon mucosa –Can interfer with fat soluble vitamins Senna –Most common herbal laxative –Promotes perastalsis

Antidiarrheals

BRAT Diet

Causes of Diarrhea Body defense to rid of toxins Medications Infections Ulcerative colitis Chron’s disease Irritable bowel syndrome Suprainfections (i.e., c. diff)

What’s Important About Antidiarrheals? 1. Dipenoxylate with atropine (Lomotil) –An opioid; works by slowing peristalsis in the colon –Schedule V agent – works directly on intestine *Does not have analgesic properties –Short term therapy to prevent dependence 2. Loperamide (Imodium) –Also an opioid, no narcotic effect available OTC

Antidiarrheal Adverse Effects Paralytic ileus Toxic megacolon Respiratory depression CNS depression Drowsiness Dry mouth (from atropine)

Irritable Bowel Syndrome Often referred as “spastic colon” Diarrhea alternating with constipation Drugs –Dicyclomine (Bentyl) – do not give IV –Hyoscyamine (Gastrosed)

Inflammatory Bowel Disease Ulcers in intestine –Chron’s disease –Ulcerative colitis Triggers include stress, smoking, NSAIDs Prototype drug: sulfasalazine (Azulfidine) –Watch for hepatoxicity, blood dyscraisias, renal impairment or salicylate or sulfonamide, or furosemide hypersensitivity

Nausea and Vomiting

Classes of Nausea Drugs 1.Serotonin 5-HT3 Antagonists 2.Anticholinergics 3.Antihistamines 4.Phenothiazine 5.Corticosteroids 6.Cannabinoids 7.Lorazepam

1. What Is Important About Serotonin Receptor Antagonists? Prototype: Ondansetron (Zofran) Few adverse effects –Possible headache, constipation or diarrhea, or dizziness Given orally, oral disenigrating, intravenously Common for prophylaxis

2. What Is Important About Anticholinergics and Antihistamines? Prototype Anticholinergic drug: Scopalamine (Transderm Scope) Prototype Antihistamine drug: dimenhydrinate (Dramamine) Adverse effects similar: dry mouth, constipation, urine retention, potential for sedation. Do not operate machinery

3. What’s Important About Phenothiazine? Prototype drugs: prochlorperazine (Compazine) and promethazine (Phenergan) Adverse effects: dry eyes, dry mouth, drowsiness, EPS, urinary retention, hypotension

4. What’s Important About Corticosteroids? Prototype Drug: Dexamethasone (Decadron) Used to prevent chemotherapy-induced and post surgical nausea and vomiting Used for short term due to long term side effects What long term side effects can occur with steroids?

5. Cannibinoids Prototype Drug: dronabinol (Marinol) Adverse effects: dysphoria, tachycardia Schedule II controlled substances

6. Lorazapam Lorazapam (Ativan) Adverse effects: dizziness, drowsiness, ataxia, fatigue, slurred speech, paradoxical excitation

Pancreatic Enzymes

What’s Important About Pancreatic Enzymes? Prototype Drug: pancrelipase (Pancreaze) Helps digest fats and prevent steatorrhea (fat in stool) May be given with PPIs, nectar-like juice, or sodium bicarbonate to decrease gastric acid when given in G or J tube –Pancreatic enzymes need an alkaline environment to be active