Antacids and Controllers

8/9/2019 Antacids and Controllers

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Copyright 2002, 1998, Elsevier Science (USA). All rights reserved.

Antacids andAntacids andAcidAcid--Controlling AgentsControlling Agents

AntacidsAntacids

HH22AntagonistsAntagonists

Proton Pump InhibitorsProton Pump Inhibitors


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AcidAcid--Related PathophysiologyRelated Pathophysiology

The stomach secretes:The stomach secretes:

Hydrochloric acid (HCl)Hydrochloric acid (HCl)

BicarbonateBicarbonate

PepsinogenPepsinogen

Intrinsic factorIntrinsic factor

MucusMucus

ProstaglandinsProstaglandins


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Instructors may want to useInstructors may want to use

EIC Image #121:EIC Image #121:

Stomach: Zones and Different GlandsStomach: Zones and Different Glands


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Cells of the Gastric GlandCells of the Gastric Gland

ParietalParietal

Chief Chief

MucoidMucoid


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Parietal CellsParietal Cells

Produce and secrete HClProduce and secrete HCl

Primary site of action for many acidPrimary site of action for many acid--controller drugscontroller drugs


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Chief CellsChief Cells

Secrete pepsinogen, a proenzymeSecrete pepsinogen, a proenzyme

Pepsinogen becomes PEPSIN when activated byPepsinogen becomes PEPSIN when activated byexposure to acidexposure to acid

Pepsin breaks down proteins (proteolytic)Pepsin breaks down proteins (proteolytic)


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Mucoid CellsMucoid Cells

MucusMucus--secreting cells (surface epithelial cells)secreting cells (surface epithelial cells)

Provide a protective mucous coatProvide a protective mucous coat

Protects against selfProtects against self--digestion by HCldigestion by HCl


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Hydrochloric AcidHydrochloric Acid

Secreted by the parietal cellsSecreted by the parietal cells

Maintains stomach at a pH of 1 to 4Maintains stomach at a pH of 1 to 4

Secretion stimulated by:Secretion stimulated by:

Large, fatty mealsLarge, fatty meals

Excessive amounts of alcoholExcessive amounts of alcohol

Emotional stressEmotional stress


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Instructors may want to useInstructors may want to use

EIC Image #123:EIC Image #123:

Parietal Cell Stimulation and SecretionParietal Cell Stimulation and Secretion


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AcidAcid--Related DiseasesRelated Diseases

Caused by imbalance of the three cells ofCaused by imbalance of the three cells ofthe gastric gland and their secretionsthe gastric gland and their secretions

Most common:Most common: HyperacidityHyperacidity

Most harmful:Most harmful: Peptic ulcer disease (PUD)Peptic ulcer disease (PUD)

Lay terms for overproduction of HCl by theLay terms for overproduction of HCl by the

parietal cells: indigestion, sour stomach,parietal cells: indigestion, sour stomach,heartburn, acid stomachheartburn, acid stomach


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Antacids: Mechanism of ActionAntacids: Mechanism of Action

Promote the gastric mucosal defensePromote the gastric mucosal defensemechanismsmechanisms

Secretion of:Secretion of:

Mucus: Protective barrier against HClMucus: Protective barrier against HCl

Bicarbonate: Helps buffer acidic properties ofBicarbonate: Helps buffer acidic properties ofHClHCl

Prostaglandins: Prevent activation of protonProstaglandins: Prevent activation of protonpumppump


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Antacids: Mechanism of ActionAntacids: Mechanism of Action

Antacids DO NOT prevent theAntacids DO NOT prevent theoverproduction of acid.overproduction of acid.

Acids DO neutralize the acid once its inAcids DO neutralize the acid once its inthe stomach.the stomach.


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Antacids: Drug EffectsAntacids: Drug Effects

Reduction of pain associated with acidReduction of pain associated with acid--relatedrelateddisordersdisorders

Raising gastric pH from 1.3 to 1.6 neutralizes 50%Raising gastric pH from 1.3 to 1.6 neutralizes 50%of the gastric acid.of the gastric acid.

Raising gastric pH 1 point (1.3 to 2.3) neutralizesRaising gastric pH 1 point (1.3 to 2.3) neutralizes90% of the gastric acid.90% of the gastric acid.


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AntacidsAntacids

OTC formulations available as:OTC formulations available as:

Capsules and tabletsCapsules and tablets PowdersPowders

Chewable tabletsChewable tablets SuspensionsSuspensions

Effervescent granules and tabletsEffervescent granules and tablets


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AntacidsAntacids

Aluminum saltsAluminum salts

Magnesium saltsMagnesium salts

Calcium saltsCalcium salts

Sodium bicarbonateSodium bicarbonate

Used alone or in combinationUsed alone or in combination


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AntacidsAntacids

Aluminum SaltsAluminum Salts

Forms: carbonate, hydroxide, phosphateForms: carbonate, hydroxide, phosphate

Have constipating effectsHave constipating effects

Often used with magnesium to counteractOften used with magnesium to counteractconstipationconstipation

Example: aluminum carbonate (Basaljel)Example: aluminum carbonate (Basaljel)


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AntacidsAntacids

Magnesium SaltsMagnesium Salts

Forms: carbonate, hydroxide, oxide, trisilicateForms: carbonate, hydroxide, oxide, trisilicate

Commonly cause a laxative effectCommonly cause a laxative effect

Usually used with other agents to counteract thisUsually used with other agents to counteract thiseffecteffect

Dangerous when used with renal failureDangerous when used with renal failurethe failingthe failingkidney cannot excrete extra magnesium, resulting inkidney cannot excrete extra magnesium, resulting in

accumulationaccumulation

Examples: magnesium hydroxide (MOM);Examples: magnesium hydroxide (MOM);combination products such as Maalox, Mylantacombination products such as Maalox, Mylanta(aluminum and magnesium)(aluminum and magnesium)


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AntacidsAntacids

Calcium SaltsCalcium Salts

Forms: many, but carbonate is most commonForms: many, but carbonate is most common

May cause constipationMay cause constipation

Their use may result in kidney stonesTheir use may result in kidney stones

Long duration of acid action may cause increasedLong duration of acid action may cause increasedgastric acid secretion (hyperacidity rebound)gastric acid secretion (hyperacidity rebound)

Often advertised as an extra source of dietaryOften advertised as an extra source of dietarycalciumcalcium

Example: Tums (calcium carbonate)Example: Tums (calcium carbonate)


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AntacidsAntacids

Sodium BicarbonateSodium Bicarbonate

Highly solubleHighly soluble

Quick onset, but short durationQuick onset, but short duration

May cause metabolic alkalosisMay cause metabolic alkalosis

Sodium content may cause problems in patientsSodium content may cause problems in patients

with CHF, hypertension, or renal insufficiencywith CHF, hypertension, or renal insufficiency


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Antacids and AntiflatulentsAntacids and Antiflatulents

Antiflatulents: used to relieve the painfulAntiflatulents: used to relieve the painfulsymptoms associated with gassymptoms associated with gas

Several agents are used to bind or alterSeveral agents are used to bind or alterintestinal gas, and are often added tointestinal gas, and are often added toantacid combination products.antacid combination products.


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Antacids and AntiflatulentsAntacids and Antiflatulents

OTC AntiflatulentsOTC Antiflatulents

activated charcoalactivated charcoal

simethiconesimethicone

Alters elasticity of mucusAlters elasticity of mucus--coated bubbles,coated bubbles,causing them to break.causing them to break.

Used often, but there are limited data to supportUsed often, but there are limited data to supporteffectiveness.effectiveness.


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Antacids: Side EffectsAntacids: Side Effects

Minimal, and depend on the compound usedMinimal, and depend on the compound used

Aluminum and calciumAluminum and calcium

ConstipationConstipation

MagnesiumMagnesium

DiarrheaDiarrhea

Calcium carbonateCalcium carbonate

Produces gas and belching; often combinedProduces gas and belching; often combinedwith simethiconewith simethicone


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Antacids: Drug InteractionsAntacids: Drug Interactions

ChelationChelation

Chemical binding, or inactivation, of another drugChemical binding, or inactivation, of another drug

Chemical inactivationChemical inactivation

Produces insoluble complexesProduces insoluble complexes

Result: reduced drug absorptionResult: reduced drug absorption


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Antacids: Drug InteractionsAntacids: Drug Interactions

Increased stomach pHIncreased stomach pH

Increased absorption of basic drugsIncreased absorption of basic drugs

Decreased absorption of acidic drugsDecreased absorption of acidic drugs

Increased urinary pHIncreased urinary pH

Increased excretion of acidic drugsIncreased excretion of acidic drugs

Decreased excretion of basic drugsDecreased excretion of basic drugs


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Antacids: Nursing ImplicationsAntacids: Nursing Implications

Assess for allergies and preexistingAssess for allergies and preexistingconditions that may restrict the use ofconditions that may restrict the use of

antacids, such as:antacids, such as:Fluid imbalancesFluid imbalances Renal diseaseRenal disease CHFCHF

PregnancyPregnancy GI obstructionGI obstruction

Patients with CHF or hypertension shouldPatients with CHF or hypertension shoulduse lowuse low--sodium antacids such as Riopan,sodium antacids such as Riopan,Maalox, or Mylanta II.Maalox, or Mylanta II.


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Use with caution with other medications dueUse with caution with other medications dueto the many drug interactions.to the many drug interactions.

Most medications should be given 1 to 2Most medications should be given 1 to 2hours after giving an antacid.hours after giving an antacid.

Antacids may cause premature dissolving ofAntacids may cause premature dissolving ofentericenteric--coated medications, resulting incoated medications, resulting instomach upset.stomach upset.


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Be sure that chewable tablets are chewedBe sure that chewable tablets are chewedthoroughly, and liquid forms are shaken wellthoroughly, and liquid forms are shaken well

before giving.before giving. Administer with at least 8 ounces of water toAdminister with at least 8 ounces of water to

enhance absorption (except for the rapidenhance absorption (except for the rapiddissolve forms).dissolve forms).

Caffeine, alcohol, harsh spices, and blackCaffeine, alcohol, harsh spices, and blackpepper may aggravate the underlying GIpepper may aggravate the underlying GIcondition.condition.


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Monitor for side effects:Monitor for side effects:

Nausea, vomiting, abdominal pain, diarrheaNausea, vomiting, abdominal pain, diarrhea

With calciumWith calcium--containing products: constipation,containing products: constipation,acid reboundacid rebound

Monitor for therapeutic response:Monitor for therapeutic response:

Notify heath care provider if symptoms are notNotify heath care provider if symptoms are notrelieved.relieved.


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Histamine Type 2 (HHistamine Type 2 (H22) Antagonists) Antagonists


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HH22AntagonistsAntagonists

Reduce acid secretionReduce acid secretion

All available OTCAll available OTC

Most popular drugs for treatment of acidMost popular drugs for treatment of acid--related disordersrelated disorders

cimetidine (Tagamet)cimetidine (Tagamet) famotidine (Pepcid)famotidine (Pepcid)

nizatidine (Axid)nizatidine (Axid) ranitidine (Zantac)ranitidine (Zantac)


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HH22Antagonists:Antagonists:

Mechanism of ActionMechanism of Action

Block histamine (HBlock histamine (H22) at the receptors of acid) at the receptors of acid--producing parietal cellsproducing parietal cells

Production of hydrogen ions is reduced,Production of hydrogen ions is reduced,resulting in decreased production of HClresulting in decreased production of HCl


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HH22Antagonists: Therapeutic UsesAntagonists: Therapeutic Uses

Shown to be effective for:Shown to be effective for:

Gastric ulcerGastric ulcer Gastroesophageal refluxGastroesophageal reflux

disease (GERD)disease (GERD)Upper GIUpper GI Duodenal ulcer (with orDuodenal ulcer (with or

bleedingbleeding without H. pylori)without H. pylori)

May be effective for:May be effective for:

Stress ulcersStress ulcers Peptic esophagitisPeptic esophagitis

Prevention and management of allergicPrevention and management of allergicconditions, when used with Hconditions, when used with H11 blockersblockers


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HH22Antagonists: Side EffectsAntagonists: Side Effects

Overall, less than 3% incidence of sideOverall, less than 3% incidence of sideeffectseffects

Cimetidine may induce impotence andCimetidine may induce impotence andgynecomastiagynecomastia


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HH22Antagonists: Drug InteractionsAntagonists: Drug Interactions

CimetidineCimetidine

Binds with PBinds with P--450 microsomal oxidase system in450 microsomal oxidase system in

the liver, resulting in inhibited oxidation of manythe liver, resulting in inhibited oxidation of manydrugs and increased drug levelsdrugs and increased drug levels

All HAll H22 antagonists may inhibit the absorption ofantagonists may inhibit the absorption ofdrugs that require an acidic GI environment fordrugs that require an acidic GI environment forabsorption.absorption.


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HH22Antagonists: Drug InteractionsAntagonists: Drug Interactions

SMOKING has been shown to decreaseSMOKING has been shown to decreasethe effectiveness of Hthe effectiveness of H22 blockersblockers


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HH22Antagonists: Nursing ImplicationsAntagonists: Nursing Implications

Assess for allergies and impaired renal orAssess for allergies and impaired renal orliver function.liver function.

Use with caution in patients who areUse with caution in patients who areconfused, disoriented, or elderly.confused, disoriented, or elderly.

Take 1 hour before or after antacids.Take 1 hour before or after antacids.

Ranitidine may be given intravenously;Ranitidine may be given intravenously;follow administration guidelines.follow administration guidelines.


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The parietal cells release positive hydrogenThe parietal cells release positive hydrogenions (protons) during HCl production.ions (protons) during HCl production.

This process is called the proton pump.This process is called the proton pump.

HH22 blockers and antihistamines do not stopblockers and antihistamines do not stopthe action of this pump.the action of this pump.


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Proton Pump Inhibitors:Proton Pump Inhibitors:Mechanism of ActionMechanism of Action

Irreversibly bind to H+/K+ ATPase enzyme.Irreversibly bind to H+/K+ ATPase enzyme.

This bond prevents the movement of hydrogen ionsThis bond prevents the movement of hydrogen ionsfrom the parietal cell into the stomach.from the parietal cell into the stomach.

Result: AchlorhydriaResult: AchlorhydriaALL gastric acid secretionALL gastric acid secretionis blocked.is blocked.

In order to return to normal acid secretion, theIn order to return to normal acid secretion, theparietal cell must synthesize new H+/K+ ATPase.parietal cell must synthesize new H+/K+ ATPase.


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Proton Pump Inhibitors: Drug EffectProton Pump Inhibitors: Drug Effect

Total inhibition of gastric acid secretionTotal inhibition of gastric acid secretion

lansoprazole (Prevacid)lansoprazole (Prevacid) omeprazole (Prilosec)omeprazole (Prilosec)

rabeprazole (Aciphex)rabeprazole (Aciphex) pantoprazole (Protonix)pantoprazole (Protonix)

esomeprazole (Nexium)esomeprazole (Nexium)


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Proton Pump Inhibitors:Proton Pump Inhibitors:

Therapeutic UsesTherapeutic Uses

GERD maintenance therapyGERD maintenance therapy

Erosive esophagitisErosive esophagitis

ShortShort--term treatment of active duodenal andterm treatment of active duodenal andbenign gastric ulcersbenign gastric ulcers

ZollingerZollinger--Ellison syndromeEllison syndrome

Treatment of H. pyloriTreatment of H. pylori--induced ulcersinduced ulcers


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Proton Pump Inhibitors: Side EffectsProton Pump Inhibitors: Side Effects

Safe for shortSafe for short--term therapyterm therapy

Incidence low and uncommonIncidence low and uncommon


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Nursing ImplicationsNursing Implications

Assess for allergies and history of liverAssess for allergies and history of liverdiseasedisease

Pantoprazole is the only proton pumpPantoprazole is the only proton pumpinhibitor available for parenteralinhibitor available for parenteraladministration, and can be used for patientsadministration, and can be used for patientswho are unable to take oral medicationswho are unable to take oral medications

May increase serum levels of diazepam,May increase serum levels of diazepam,phenytoin, and cause increased chance forphenytoin, and cause increased chance forbleeding with warfarinbleeding with warfarin


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Nursing ImplicationsNursing Implications

Instruct the patient taking omeprazole:Instruct the patient taking omeprazole:

It should be taken before meals.It should be taken before meals.

The capsule should be swallowed whole, notThe capsule should be swallowed whole, notcrushed, opened or chewed.crushed, opened or chewed.

It may be given with antacids.It may be given with antacids.

Emphasize that the treatment will be shortEmphasize that the treatment will be short--term.term.


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Other DrugsOther Drugs

sucralfate (Carafate)sucralfate (Carafate)

misoprostol (Cytotec)misoprostol (Cytotec)


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Sucralfate (Carafate)Sucralfate (Carafate)

Cytoprotective agentCytoprotective agent

Used for stress ulcers, erosions, PUDUsed for stress ulcers, erosions, PUD

Attracted to and binds to the base of ulcersAttracted to and binds to the base of ulcersand erosions, forming a protective barrierand erosions, forming a protective barrierover these areasover these areas

Protects these areas from pepsin, whichProtects these areas from pepsin, whichnormally breaks down proteins (makingnormally breaks down proteins (makingulcers worse)ulcers worse)


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Sucralfate (Carafate)Sucralfate (Carafate)

Little absorption from the gutLittle absorption from the gut

May cause constipation, nausea, and dryMay cause constipation, nausea, and dry

mouthmouth May impair absorption of other drugs,May impair absorption of other drugs,

especially tetracyclineespecially tetracycline

Binds with phosphate; may be used inBinds with phosphate; may be used in

chronic renal failure to reduce phosphatechronic renal failure to reduce phosphatelevelslevels

Do not administer with other medicationsDo not administer with other medications


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Synthetic prostaglandin analogueSynthetic prostaglandin analogue

Prostaglandins have cytoprotective activity:Prostaglandins have cytoprotective activity:

Protect gastric mucosa from injury by enhancingProtect gastric mucosa from injury by enhancinglocal production of mucus or bicarbonatelocal production of mucus or bicarbonate

Promote local cell regenerationPromote local cell regeneration

Help to maintain mucosal blood flowHelp to maintain mucosal blood flow


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Used for prevention of NSAIDUsed for prevention of NSAID--inducedinducedgastric ulcersgastric ulcers

Doses that are therapeutic enough to treatDoses that are therapeutic enough to treatduodenal ulcers often produce abdominalduodenal ulcers often produce abdominalcramps, diarrheacramps, diarrhea

Antacids and Controllers

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