Antacids and controlling agents

Antacids andAntacids andAcid-Controlling AgentsAcid-Controlling Agents

AntacidsAntacids

HH22 Antagonists Antagonists

Proton Pump InhibitorsProton Pump Inhibitors

Acid-Related PathophysiologyAcid-Related Pathophysiology

The stomach secretes:The stomach secretes:

• Hydrochloric acid (HCl)Hydrochloric acid (HCl)

• BicarbonateBicarbonate

• PepsinogenPepsinogen

• Intrinsic factorIntrinsic factor

• MucusMucus

• ProstaglandinsProstaglandins

Glands of the StomachGlands of the Stomach

• CardiacCardiac

• PyloricPyloric

• Gastric*Gastric*

*The gastric glands are the largest in number*The gastric glands are the largest in number

Cells of the Gastric GlandCells of the Gastric Gland

• ParietalParietal

• ChiefChief

• MucoidMucoid


Parietal CellsParietal Cells

• Produce and secrete HClProduce and secrete HCl

• Primary site of action for many acid-controller drugsPrimary site of action for many acid-controller drugs


Chief CellsChief Cells

• Secrete pepsinogen, a proenzymeSecrete pepsinogen, a proenzyme

• Pepsinogen becomes PEPSIN when activated by Pepsinogen becomes PEPSIN when activated by exposure to acidexposure to acid

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


Mucoid CellsMucoid Cells

• Mucus-secreting cells (surface epithelial cells)Mucus-secreting cells (surface epithelial cells)

• Provide a protective mucous coat Provide a protective mucous coat

• Protects against self-digestion by HClProtects against self-digestion by HCl

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

Acid-Related DiseasesAcid-Related Diseases

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

• Most common:Most common: HyperacidityHyperacidity

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

• Lay terms for overproduction of HCl by the Lay terms for overproduction of HCl by the parietal cells: indigestion, sour stomach, parietal cells: indigestion, sour stomach, heartburn, acid stomachheartburn, acid stomach

Antacids: Mechanism of ActionAntacids: Mechanism of Action

Promote the gastric mucosal defense Promote the gastric mucosal defense mechanismsmechanisms

• Secretion of:Secretion of:

– Mucus: Protective barrier against HClMucus: Protective barrier against HCl

– Bicarbonate: Helps buffer acidic properties of Bicarbonate: Helps buffer acidic properties of HClHCl

– Prostaglandins: Prevent activation of proton Prostaglandins: Prevent activation of proton pumppump

Antacids: Mechanism of ActionAntacids: Mechanism of Action

• Antacids DO NOT prevent the Antacids DO NOT prevent the overproduction of acid.overproduction of acid.

• Acids DO neutralize the acid once it’s in Acids DO neutralize the acid once it’s in the the stomach.stomach.

Antacids: Drug EffectsAntacids: Drug Effects

Reduction of pain associated with acid-related Reduction of pain associated with acid-related disordersdisorders

• 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.

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

AntacidsAntacids

• Aluminum saltsAluminum salts

• Magnesium saltsMagnesium salts

• Calcium saltsCalcium salts

• Sodium bicarbonateSodium bicarbonate

Used alone or in combinationUsed alone or in combination

AntacidsAntacids

Aluminum SaltsAluminum Salts

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

• Have constipating effectsHave constipating effects

• Often used with magnesium to counteract Often used with magnesium to counteract constipationconstipation

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

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 this Usually used with other agents to counteract this effecteffect

• Dangerous when used with renal failure—the failing Dangerous when used with renal failure—the failing kidney cannot excrete extra magnesium, resulting in kidney cannot excrete extra magnesium, resulting in accumulationaccumulation

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

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

• Often advertised as an extra source of dietary Often advertised as an extra source of dietary calciumcalcium

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

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 patients Sodium content may cause problems in patients with CHF, hypertension, or renal insufficiencywith CHF, hypertension, or renal insufficiency

Antacids and AntiflatulentsAntacids and Antiflatulents

• Antiflatulents: used to relieve the painful Antiflatulents: used to relieve the painful symptoms associated with gassymptoms associated with gas

• Several agents are used to bind or alter Several agents are used to bind or alter intestinal gas, and are often added to intestinal gas, and are often added to antacid combination products.antacid combination products.

Antacids and AntiflatulentsAntacids and Antiflatulents

OTC AntiflatulentsOTC Antiflatulents

• activated charcoalactivated charcoal

• simethiconesimethicone

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

– Used often, but there are limited data to support Used often, but there are limited data to support effectiveness.effectiveness.

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 combined Produces gas and belching; often combined with simethiconewith simethicone

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

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

Antacids: Nursing ImplicationsAntacids: Nursing Implications

• Assess for allergies and preexisting Assess for allergies and preexisting conditions that may restrict the use of conditions 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 should Patients with CHF or hypertension should use low-sodium antacids such as Riopan, use low-sodium antacids such as Riopan, Maalox, or Mylanta II.Maalox, or Mylanta II.


• Use with caution with other medications due Use with caution with other medications due to the many drug interactions.to the many drug interactions.

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

• Antacids may cause premature dissolving of Antacids may cause premature dissolving of enteric-coated medications, resulting in enteric-coated medications, resulting in stomach upset.stomach upset.


• Be sure that chewable tablets are chewed Be sure that chewable tablets are chewed thoroughly, and liquid forms are shaken well thoroughly, and liquid forms are shaken well before giving.before giving.

• Administer with at least 8 ounces of water to Administer with at least 8 ounces of water to enhance absorption (except for the “rapid enhance absorption (except for the “rapid dissolve” forms).dissolve” forms).

• Caffeine, alcohol, harsh spices, and black Caffeine, alcohol, harsh spices, and black pepper may aggravate the underlying GI pepper may aggravate the underlying GI condition.condition.


• Monitor for side effects:Monitor for side effects:

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

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

• Monitor for therapeutic response:Monitor for therapeutic response:

– Notify heath care provider if symptoms are not Notify heath care provider if symptoms are not relieved.relieved.

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

HH22 Antagonists Antagonists

• Reduce acid secretionReduce acid secretion

• All available OTCAll available OTC

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

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

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

HH22 Antagonists: 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

HH22 Antagonists: Drug Effect Antagonists: Drug Effect

• Suppressed acid secretion in the stomachSuppressed acid secretion in the stomach

HH22 Antagonists: Therapeutic Uses Antagonists: Therapeutic Uses

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

Gastric ulcerGastric ulcer Gastroesophageal reflux Gastroesophageal reflux disease (GERD)disease (GERD)

Upper GI Upper GI Duodenal ulcer (with or Duodenal ulcer (with or bleeding bleeding without H. pylori) without H. pylori)

• May be effective for:May be effective for:

– Stress ulcersStress ulcers Peptic esophagitisPeptic esophagitis

– Prevention and management of allergic Prevention and management of allergic conditions, when used with Hconditions, when used with H11 blockers blockers

HH22 Antagonists: Side Effects Antagonists: Side Effects

• Overall, less than 3% incidence of side Overall, less than 3% incidence of side effectseffects

• Cimetidine may induce impotence and Cimetidine may induce impotence and gynecomastiagynecomastia

HH2 2 Antagonists: Drug InteractionsAntagonists: Drug Interactions

• CimetidineCimetidine

– Binds with P-450 microsomal oxidase system in Binds with P-450 microsomal oxidase system in the liver, resulting in inhibited oxidation of many the liver, resulting in inhibited oxidation of many drugs and increased drug levelsdrugs and increased drug levels

– All HAll H22 antagonists may inhibit the absorption of antagonists may inhibit the absorption of drugs that require an acidic GI environment for drugs that require an acidic GI environment for absorption.absorption.

HH22 Antagonists: Drug Interactions Antagonists: Drug Interactions

• SMOKING has been shown to decrease SMOKING has been shown to decrease the effectiveness of H the effectiveness of H22 blockers blockers

HH22 Antagonists: Nursing Implications Antagonists: Nursing Implications

• Assess for allergies and impaired renal or Assess for allergies and impaired renal or liver function.liver function.

• Use with caution in patients who are Use with caution in patients who are confused, 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; follow Ranitidine may be given intravenously; follow administration guidelines.administration guidelines.


• The parietal cells release positive hydrogen The parietal cells release positive hydrogen ions (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 stop blockers and antihistamines do not stop the action of this pump.the action of this pump.

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

• Result: Achlorhydria—ALL gastric acid secretion Result: Achlorhydria—ALL gastric acid secretion is blocked.is blocked.

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

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 omeprazole (Prilosec)(Prilosec)

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

esomeprazole (Nexium)esomeprazole (Nexium)

Proton Pump Inhibitors: Proton Pump Inhibitors: Therapeutic UsesTherapeutic Uses

• GERD maintenance therapyGERD maintenance therapy

• Erosive esophagitisErosive esophagitis

• Short-term treatment of active duodenal and Short-term treatment of active duodenal and benign gastric ulcersbenign gastric ulcers

• Zollinger-Ellison syndromeZollinger-Ellison syndrome

• Treatment of H. pylori-induced ulcersTreatment of H. pylori-induced ulcers

Proton Pump Inhibitors: Side EffectsProton Pump Inhibitors: Side Effects

• Safe for short-term therapySafe for short-term therapy

• Incidence low and uncommonIncidence low and uncommon

Proton Pump Inhibitors: Proton Pump Inhibitors: Nursing ImplicationsNursing Implications

• Assess for allergies and history of liver Assess for allergies and history of liver diseasedisease

• Pantoprazole is the only proton pump Pantoprazole is the only proton pump inhibitor available for parenteral inhibitor available for parenteral administration, and can be used for patients administration, and can be used for patients who 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 for phenytoin, and cause increased chance for bleeding with warfarinbleeding with warfarin

Proton Pump Inhibitors: Proton Pump Inhibitors: 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, not The capsule should be swallowed whole, not crushed, 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 short-term.Emphasize that the treatment will be short-term.

Other DrugsOther Drugs

• sucralfate (Carafate)sucralfate (Carafate)

• misoprostol (Cytotec)misoprostol (Cytotec)

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 ulcers Attracted to and binds to the base of ulcers and erosions, forming a protective barrier and erosions, forming a protective barrier over these areasover these areas

• Protects these areas from pepsin, which Protects these areas from pepsin, which normally breaks down proteins (making normally breaks down proteins (making ulcers worse)ulcers worse)

Sucralfate (Carafate)Sucralfate (Carafate)

• Little absorption from the gutLittle absorption from the gut

• May cause constipation, nausea, and dry May 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 in Binds with phosphate; may be used in chronic renal failure to reduce phosphate chronic renal failure to reduce phosphate levelslevels

• Do not administer with other medicationsDo not administer with other medications

misoprostol (Cytotec)misoprostol (Cytotec)

• Synthetic prostaglandin analogueSynthetic prostaglandin analogue

• Prostaglandins have cytoprotective activity:Prostaglandins have cytoprotective activity:

– Protect gastric mucosa from injury by enhancing Protect gastric mucosa from injury by enhancing local 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

misoprostol (Cytotec)misoprostol (Cytotec)

• Used for prevention of NSAID-induced Used for prevention of NSAID-induced gastric ulcersgastric ulcers

• Doses that are therapeutic enough to treat Doses that are therapeutic enough to treat duodenal ulcers often produce abdominal duodenal ulcers often produce abdominal cramps, diarrheacramps, diarrhea

Antacids and controlling agents

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