Chapter 50 - PowerPoint Presentation

phoebe-click . @phoebe-click

448 views
Uploaded On 2015-10-18

About Share Download

Chapter 50 - PPT Presentation

Link:

Copy

Embed:

<iframe width="560" height="315" src="https://www.docslides.com/embed/164775" frameborder="0" allowfullscreen></iframe>

Download Presentation from below link

Download Presentation The PPT/PDF document "Chapter 50" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.

Presentation Transcript

Slide1

Chapter 50

Acid-Controlling DrugsDSN Kevin dobi, MS, Aprn

The stomach secretes:Hydrochloric acid (HCl)BicarbonatePepsinogenIntrinsic factorMucusProstaglandinsAcid-Related Pathophysiology

Cardiac Pyloric GastricThe cells of the gastric gland are the largest in number and of primary importance when discussing acid controlGlands of the StomachCopyright © 2014 by Mosby, an imprint of Elsevier Inc.

4Slide5

5Slide6

Parietal cellsProduce and secrete HClPrimary site of action for many of the drugs used to treat acid-related disordersCells of the Gastric Gland (cont’d)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

6Slide7

Chief cellsSecrete pepsinogen, a proenzymePepsinogen becomes pepsin when activated by exposure to acidPepsin breaks down proteins (proteolytic)Cells of the Gastric Gland

Mucous cellsMucus-secreting cells (surface epithelial cells)Provide a protective mucus coat Protect against self-digestion by HCl and digestive enzymesCells of the Gastric Gland (cont’d)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

9Slide10

Secreted by parietal cells when stimulated by food, caffeine, chocolate, and alcoholMaintains stomach at pH of 1 to 4Acidity aids in the proper digestion of food and defenses against microbial infection via the GI tractSecretion also stimulated by:Large fatty mealsEmotional stressHydrochloric Acid

Peptic ulcer disease (PUD)Gastric or duodenal ulcers that involve digestion of the GI mucosa by the enzyme pepsinHelicobacter pylori (H. pylori)Bacterium found in GI tract of 90% of patients with duodenal ulcers and 70% of those with gastric ulcersFirst-line therapy includes a 10- to 14-day course of a proton pump inhibitor and antibioticsAcid-Related Diseases

Stress-related mucosal damageGI lesions are a common finding in ICU patients, especially within the first 24 hours after admissionFactors include decreased blood flow, mucosal ischemia, hypoperfusion, and reperfusion injury Nasogastric (NG) tubes and ventilators predispose patients to GI bleedingA histamine receptor–blocking drug or a proton pump inhibitor are given for preventionAcid-Related Diseases (cont’d)

13Slide14

Basic compounds used to neutralize stomach acidSalts of aluminum, magnesium, calcium, and/or sodiumMany antacid preparations also contain the antiflatulent (antigas) drug simethicone AntacidsCopyright © 2014 by Mosby, an imprint of Elsevier Inc.

14Slide15

Do not prevent the overproduction of acid but instead help to neutralize acid secretionsPromote gastric mucosal defensive mechanismsStimulate secretion of:Mucus: protective barrier against HClBicarbonate: helps buffer acidic properties of HClProstaglandins: prevent activation of proton pumpAntacids: Mechanism of Action

Reduction of pain associated with acid-related disordersRaising gastric pH 1 point (1.3 to 2.3) neutralizes 90% of the gastric acidReducing acidity reduces pain as a result of:Base-mediated inhibition of the protein-digesting ability of pepsinIncrease in the resistance of the stomach lining to irritationIncrease in the tone of the cardiac sphincterAntacids: Drug Effects

Over-the-counter formulations available as:Capsules and tablets PowdersChewable tabletsSuspensionsEffervescent granules and tabletsAntacids (cont’d)

Used alone or in combinationAluminum saltsMagnesium saltsCalcium saltsSodium bicarbonateAntacids (cont’d)

Have constipating effectsOften used with magnesium to counteract constipationOften recommended for patients with renal disease (more easily excreted)ExamplesAluminum carbonate: BasaljelHydroxide salt: AlternaGELCombination products (aluminum and magnesium): Gaviscon, Maalox, Mylanta, Di-GelAntacids: Aluminum Salts

Commonly cause diarrhea; usually used with other drugs to counteract this effectDangerous when used with renal failure—the failing kidney cannot excrete extra magnesium, resulting in accumulation Antacids: Magnesium Salts

Examples Hydroxide salt: magnesium hydroxide (Milk of Magnesia)Carbonate salt: Gaviscon (also a combination product)Combination products such as Maalox, Mylanta (aluminum and magnesium)Antacids: Magnesium Salts (cont’d)

Many forms, but carbonate is most commonMay cause constipation, kidney stonesAlso not recommended for patients with renal disease—may accumulate to toxic levelsLong duration of acid action—may cause increased gastric acid secretion (hyperacidity rebound)Often advertised as an extra source of dietary calciumExample: Tums (calcium carbonate)Antacids: Calcium Salts

Highly solubleBuffers the acidic properties of HClQuick onset, but short durationMay cause metabolic alkalosisSodium content may cause problems in patients with heart failure, hypertension, or renal insufficiency Antacids: Sodium Bicarbonate

A patient who has chronic renal failure wants to self-treat with an antacid for occasional heartburn. Which medication is the best choice for this patient?A magnesium-containing antacidA calcium-containing antacid

An aluminum-containing antacid

Because of renal problems, the patient should not take antacids for this problem.Slide25

Antiflatulents: used to relieve the painful symptoms associated with gasSeveral drugs are used to bind or alter intestinal gas and are often added to antacid combination productssimethiconeAntacids and AntiflatulentsCopyright © 2014 by Mosby, an imprint of Elsevier Inc.

25Slide26

Minimal and depend on the compound usedAluminum and calciumConstipationMagnesiumDiarrheaCalcium carbonateProduces gas and belching; often combined with simethiconeAntacids: Adverse Effects

Adsorption of other drugs to antacidsReduces the ability of the other drug to be absorbed into the bodyChelationChemical binding, or inactivation, of another drugProduces insoluble complexesResult: reduced drug absorptionAntacids: Drug Interactions

Increased stomach pHIncreased absorption of basic drugsDecreased absorption of acidic drugsIncreased urinary pHIncreased excretion of acidic drugsDecreased excretion of basic drugsAntacids: Drug Interactions (cont’d)

Reduce acid secretionAll available over the counter in lower dosage formsMost popular drugs for treatment of acid-related disorderscimetidine (Tagamet) nizatidine (Axid) famotidine (Pepcid)ranitidine (Zantac)Histamine 2 (H2

Competitively block the H2 receptor of acid-producing parietal cellsReduced hydrogen ion secretion from the parietal cellsIncrease in the pH of the stomach Relief of many of the symptoms associated with hyperacidity-related conditionsH2 Antagonists:

Drug effectSuppressed acid secretion in the stomachIndicationsGastroesophageal reflux disease (GERD)Peptic ulcer disease (PUD)Erosive esophagitisAdjunct therapy to control upper GI bleedingZollinger-Ellison syndromeH

31Slide32

Overall, very few adverse effectsCentral nervous system adverse effects in elderly patients include confusion and disorientationCimetidine may induce impotence and gynecomastiaThrombocytopenia has been reported with ranitidine and famotidineH2 Antagonists: Adverse Effects

cimetidine (Tagamet) Binds with P-450 microsomal oxidase system in the liver, resulting in inhibited oxidation of many drugs and increased drug levelsAll H2 antagonists may inhibit the absorption of drugs that require an acidic GI environment for absorptionH2 Antagonists: Drug Interactions

Smoking has been shown to decrease the effectiveness of H2 blockersFor optimal results, H2 receptor antagonists are taken 1 to 2 hours before antacidsH2 Antagonists: Drug Interactions (cont’d)

When working with an elderly patient who has been admitted for a possible gastrointestinal bleed, the nurse identifies which drug as having the potential to cause confusion and disorientation?An antacidA proton pump inhibitor

An H

antagonist

A mucosal protectantSlide36

The parietal cells release positive hydrogen ions (protons) during HCl productionThis process is called the proton pumpH2 blockers and antihistamines do not stop the action of this pumpProton Pump Inhibitors (PPIs)

lansoprazole (Prevacid) omeprazole (Prilosec) rabeprazole (AcipHex) pantoprazole (Protonix) esomeprazole (Nexium)Proton Pump Inhibitors

Irreversibly bind to H+/K+ ATPase enzymeThis bond prevents the movement of hydrogen ions from the parietal cell into the stomachResults in achlorhydria—ALL gastric acid secretion is temporarily blockedTo return to normal acid secretion, the parietal cell must synthesize new H+/K+ ATPase

38Slide39

GERD Erosive esophagitisShort-term treatment of active duodenal and benign gastric ulcersZollinger-Ellison syndromeNonsteroidal antiinflammatory drug (NSAID)–induced ulcersStress ulcer prophylaxisTreatment of Helicobacter pylori–induced ulcersGiven with an antibiotic

39Slide40

PPIs are generally well toleratedPossible predisposition to GI tract infections (Clostridium difficile)Osteoporosis and risk of wrist, hip, and spine fractures in long-term usersPneumoniaDepletion of magnesium Proton Pump Inhibitors: Adverse Effects

41Slide42

Cytoprotective drugUsed for stress ulcers, peptic ulcer diseaseAttracted to and binds to the base of ulcers and erosions, forming a protective barrier over these areasProtects these areas from pepsin, which normally breaks down proteins (making ulcers worse)Sucralfate (Carafate)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

42Slide43

Little absorption from the gutMay cause constipation, nausea, and dry mouthMay impair absorption of other drugs—give other drugs at least 2 hours before sucralfateDo not administer with other medicationsBinds with phosphate; may be used in chronic renal failure to reduce phosphate levelsSucralfate (Carafate) (cont’d)

Prostaglandin E analogProstaglandins have cytoprotective activityProtect gastric mucosa from injury by enhancing local production of mucus or bicarbonatePromote local cell regenerationHelp to maintain mucosal blood flowMisoprostol (Cytotec)

Used for prevention of NSAID-induced gastric ulcersDoses that are therapeutic enough to treat duodenal ulcers often produce abdominal cramps, diarrheaMisoprostol (Cytotec) (cont’d)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

45Slide46

Antiflatulent drugUsed to reduce the discomforts of gastric or intestinal gas (flatulence)Alters elasticity of mucus-coated gas bubbles, breaking them into smaller onesResult is decreased gas pain and increased expulsion via mouth or rectumSimethiconeCopyright © 2014 by Mosby, an imprint of Elsevier Inc.

46Slide47

Simethicone (Mylicon) is often combined with calcium carbonate antacids because:an increased antacid effect will result when these drugs are given in combination.simethicone helps to reduce the gas that is caused by the calcium antacids.

simethicone reduces the diarrhea that is caused by the calcium.

simethicone improves the taste of the calcium tablets, which must be chewed.Slide48

Assess for allergies and preexisting conditions that may restrict the use of antacids, such as: Fluid imbalances Renal disease GI obstruction Heart failure (HF) Pregnancy Patients with heart failure or hypertension should not use antacids with high sodium contentNursing Implications: Antacids

Use with caution with other medications because of the many drug interactionsMost medications should be administered 1 to 2 hours after an antacidAntacids may cause premature dissolving of enteric-coated medications, resulting in stomach upsetNursing Implications: Antacids (cont’d)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

49Slide50

Be sure that chewable tablets are chewed thoroughly, and liquid forms are shaken well before givingAdminister with at least 8 ounces of water to enhance absorption (except for “rapid-dissolve” forms)Nursing Implications: Antacids (cont’d)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

50Slide51

Long-term self-medication with antacids may mask symptoms of serious underlying diseases, such as malignancy or bleeding ulcersIf symptoms remain ongoing, patient should seek medical evaluationNursing Implications: Antacids (cont’d)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

51Slide52

Monitor for adverse effectsNausea, vomiting, abdominal pain, diarrheaWith calcium-containing products: constipation, acid reboundMonitor for therapeutic responseNotify health care provider if symptoms are not relievedNursing Implications: Antacids (cont’d)

Assess for allergies and impaired renal or liver functionUse with caution in patients who are confused, disoriented, or elderlyTake 1 to 2 hours before antacidsFor intravenous doses, follow administration guidelinesNursing Implications: H2 Antagonists

Assess for allergies and history of liver diseaseNot all are available for parenteral administrationMay increase serum levels of diazepam and phenytoin; may increase chance for bleeding with warfarinNursing Implications: Proton Pump Inhibitors

The granules of pantoprazole capsules may be given via nasogastric (NG) tubes, but the NG tube must be at least 16 gauge or the tube may become cloggedCapsule contents may be opened and mixed with apple juice, but do not chew or crush delayed-release granulesNursing Implications: Proton Pump Inhibitors (cont’d)Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

55Slide56

When providing education regarding the use of proton pump inhibitors, which statement will the nurse include?“Take the medication along with the first meal of the day.”“Take the medication on an empty stomach, 30 to 60 minutes before eating.”

“Take the medication when you have symptoms of heartburn.”

“Take the medication at bedtime with a snack.”