Antacids. ppt

Antacids.

1. AntacidsAntacids
A. Prof. Alaa ZakyA. Prof. Alaa Zaky
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2. DigestionDigestion
Digestion involves Digestion involves the the break down of foodsbreak down of foods, ,
particularly particularly carbohydrates, lipids,carbohydrates, lipids, and and proteinsproteins
into forms that into forms that can be metabolized in the cellscan be metabolized in the cells
Amylase found Amylase found in in salivasaliva begins the begins the breakdown of breakdown of
starchesstarches
The breakdown of proteins The breakdown of proteins occurs primarily in the occurs primarily in the
stomach through the action of the stomach through the action of the enzyme pepsin enzyme pepsin
and and Hydrochloric acidHydrochloric acid
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3. The StomachThe Stomach
The walls of the stomach The walls of the stomach are lined with cells that are lined with cells that secretesecrete mucus, mucus,
pepsinogen pepsinogen and and hydrochloric acidhydrochloric acid..
The The hydrochloric acid conc hydrochloric acid conc of the stomach of the stomach range of about 1.5 to 2.5.range of about 1.5 to 2.5.
The mucus lining The mucus lining of the stomach of the stomach protects the stomach protects the stomach walls from walls from
the the action of stomach acidaction of stomach acid
Secretary Functions of the Stomach LiningSecretary Functions of the Stomach Lining
Parietal cells Parietal cells secrete secrete hydrochlorichydrochloric (HCl) (HCl)
Chief cells Chief cells secrete secrete pepsinogenpepsinogen
Mucoid cells Mucoid cells secrete secrete mucusmucus
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4. Acid Indigestion and “Acid Indigestion and “HeartburnHeartburn””
When When excess acid excess acid is produced a condition known is produced a condition known
as as acid indigestion resultsacid indigestion results..
If excess acid is forced into the esophagus If excess acid is forced into the esophagus acid acid
reflux or “reflux or “heart burnheart burn” results.” results.
High acid conc can damage the stomach High acid conc can damage the stomach lining lining
resulting in resulting in ulcers.ulcers.
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5. Causes of Acid IndigestionCauses of Acid Indigestion
Excess stomach acid results in a state of discomfort Excess stomach acid results in a state of discomfort
known as known as acid indigestionacid indigestion
Acid indigestion may result form a variety of factors Acid indigestion may result form a variety of factors
includingincluding::
– OvereatingOvereating
– Alcohol consumptionAlcohol consumption
– Eating certain foodsEating certain foods
– AnxietyAnxiety
– SmokingSmoking
– Certain Drugs, i.e. Certain Drugs, i.e. AspirinAspirin
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6. AntacidsAntacids
Definition.Definition.
Antacid is a medicine that neutralize stomach acidityAntacid is a medicine that neutralize stomach acidity
Antacid should be used only for Antacid should be used only for relief relief of of mild heartburn mild heartburn
or or indigestionindigestion
Mechanism of actionMechanism of action
Antacids perform a Antacids perform a neutralizationneutralization reaction reaction
It It increases the PH increases the PH to reduce activity in stomachto reduce activity in stomach
When Gastric HCl reaches nerves in the Gastro Intestinal When Gastric HCl reaches nerves in the Gastro Intestinal
Mucosa, they signal pain to the CNSMucosa, they signal pain to the CNS
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7. 1-1- Antacid Compounds Antacid Compounds
Antacids are weak bases Antacids are weak bases that are used that are used to to neutralize excess stomach neutralize excess stomach
acidacid
Most antacids are weak inorganic Most antacids are weak inorganic basesbases
Common examples for Some common antacid reactions include
include
–CaCOCaCO
33 CaCOCaCO
33 + 2 HCl + 2 HCl  CaCl CaCl
22 + H + H
22O + COO + CO
2 2
–NaHCONaHCO
33 NaHCO NaHCO
33 + HCl + HCl  NaCl NaCl
+ H + H
22O + COO + CO
22
–Al(OH)Al(OH)
33 Al(OH) Al(OH)
3 3 + 3 HCl + 3 HCl  AlCl AlCl
33 + 3 H + 3 H
22OO
–Mg(OH)Mg(OH)
22 Mg(OH) Mg(OH)
2 2 + 2 HCl + 2 HCl  MgCl MgCl
22 + 2 H + 2 H
22OO
–MgO and Mg(OH)MgO and Mg(OH)
22 (Milk of Magnesia) (Milk of Magnesia)
– MgO + 2 HCl MgO + 2 HCl  MgCl MgCl
22 + H + H
22OO
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8. Antacids
Magnesium salts:Magnesium salts:
Forms: Forms: carbonate hydroxidecarbonate hydroxide, , oxide, trisilicateoxide, trisilicate..
Commonly cause Commonly cause a a laxative effectlaxative effect..
Usually used with Usually used with the the other agents other agents to counteract this effectto counteract this effect..
Dangerous when used with renal failureDangerous when used with renal failure-the Failing kidney cannot -the Failing kidney cannot
excrete magnesium, resulting in accumulation.excrete magnesium, resulting in accumulation.
ExampleExample : :mag hydroxide(MOMmag hydroxide(MOM);combination products such as );combination products such as
MaaloxMaalox, , aluminium & magnesiumaluminium & magnesium..
Calcium salts:Calcium salts:
Forms: Forms: many but many but carbonatecarbonate is the most common. is the most common.
May cause May cause constipationconstipation..
Their use may Their use may result in result in kidney stoneskidney stones..
Long duration of acid Long duration of acid action may cause increase of gastric acid action may cause increase of gastric acid
secretion (secretion (hyperacidity boundhyperacidity bound))
Often advertised as an extra source of dietary calcium.Often advertised as an extra source of dietary calcium.
ExampleExample: : Calcium carbonateCalcium carbonate

9. Antacids
Sodium Bicarbonate:Sodium Bicarbonate:
Highly soluble.Highly soluble.
Quick onsetQuick onset, but , but short durationshort duration..
May cause May cause metabolic alkalosismetabolic alkalosis..
Sodium content Sodium content may may cause problems in patients with cause problems in patients with
hypertension or renal insufficiencyhypertension or renal insufficiency..
Aluminum salts:Aluminum salts:
Forms: Forms: carbonate, hydroxide, phosphatecarbonate, hydroxide, phosphate..
Have Have constipating effectsconstipating effects..
Often used Often used with with magnesiummagnesium to counteract constipationto counteract constipation..
Example: Example: aluminum carbonatealuminum carbonate

10. ANTACID BRANDSANTACID BRANDS
Alka-Seltzer – NaHCO3 and/or KHCO3
 Andrews Antacid – CaCO3 MgCO3
 Equate – Al(OH)3 and Mg(OH)2
 Gaviscon – Al(OH)3
 Maalox (liquid) – Al(OH)3 and Mg(OH)2
 Maalox (tablet) – CaCO3
 Milk of Magnesia – Mg(OH)2
Pepto-Bismol - bismuth subsalicylatebismuth subsalicylate
Pepto-Bismol Children’s – CaCO3

11. Effect of AntacidsEffect of Antacids
In addition to neutralizing excess stomach acid they
may be helpful in preventing inflammation, relieving
pain and discomfort, and allowing the mucus layer
in the stomach lining to heal.
They are often used to treat ulcers by preventing
the stomach acids from attacking the stomach
lining allowing it to heal.
Mucus
Lining
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12. Antacid Side EffectsAntacid Side Effects
Antacids Antacids are relatively harmless but they can have minor are relatively harmless but they can have minor
contraindicationscontraindications
Magnesium CompoundsMagnesium Compounds may cause may cause diarrheadiarrhea
Aluminum CompoundsAluminum Compounds may cause may cause constipationconstipation and and
they also may they also may interfere with the adsorption of phosphates interfere with the adsorption of phosphates in in
the formation of bonesthe formation of bones. This is more likely to be true if they . This is more likely to be true if they
are taken for an extended period of timeare taken for an extended period of time
CarbonatesCarbonates may generate carbon dioxide leading to may generate carbon dioxide leading to
flatulence flatulence and and reflex hyperacidityreflex hyperacidity..
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13. Antacid InteractionsAntacid Interactions
Binding of other drugs Binding of other drugs to the antacid causes to the antacid causes
reduced availability of the other drugs reduced availability of the other drugs to the clientto the client
Chemical inactivationChemical inactivation
Increases stomach and urine pH Increases stomach and urine pH (alkaline), which (alkaline), which
decreases the absorption and excretion of certain decreases the absorption and excretion of certain
drugsdrugs

14. 2-2- H2 Blockers H2 Blockers
H2 blockers H2 blockers impede acid production in the
stomach by blocking the actions of histamine, a
subs produced by the body that increase increase acid
secretion in the stomach.
These drugs cannot cure ulcers, but in certain
cases they are useful. They are effective only for
duodenal ulcers, however, and have little effect
on stomach (gastric) ulcers.
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15. 2- 2- H2 BlockersH2 Blockers
Four H2 blockers are currently available over Four H2 blockers are currently available over
the counter in the US: the counter in the US:
– FamotidineFamotidine (Pepcid AC) (Pepcid AC)
– Cimetidine Cimetidine (Tagamet)(Tagamet)
– RanitidineRanitidine (Zantac) (Zantac)
– NizatidineNizatidine (Axid). (Axid).
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16. 3- 3- Proton Pump InhibitorsProton Pump Inhibitors
Proton Pump InhibitorsProton Pump Inhibitors reducereduce the the production of acid by production of acid by
blocking the enzyme in the wall of the stomach blocking the enzyme in the wall of the stomach that that
produces acid. produces acid.
Inhibitors do not neutralize Inhibitors do not neutralize excess acid excess acid but inhibit the but inhibit the
initial productioninitial production of hydrochloric acid of hydrochloric acid
The reduction of acid prevents ulcers The reduction of acid prevents ulcers and and allows any allows any
ulcers ulcers that exist in the that exist in the esophagusesophagus, , stomach stomach and and
duodenumduodenum to to healheal. .
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17. 3- 3- Proton Pump InhibitorsProton Pump Inhibitors
Proton Pump Inhibitors are generally available only by Proton Pump Inhibitors are generally available only by
prescription but low doses of some products are now prescription but low doses of some products are now
approved for over the counter useapproved for over the counter use
Commonly prescribed Proton Pump inhibitors includeCommonly prescribed Proton Pump inhibitors include
–RabeprazoleRabeprazole (Aciphex) (Aciphex)
–LansoprazoleLansoprazole (Prevacid) (Prevacid)
–OmeprazoleOmeprazole (Prilosec) (Prilosec)
–EsomeprazoleEsomeprazole (Nexium (Nexium))
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18. Helicobacter Pylori Helicobacter Pylori
An organism associated with the development of An organism associated with the development of
peptic ulcer diseasepeptic ulcer disease
TreatmentTreatment
–MetronidazoleMetronidazole (Flagyl), an antimicrobial agent, along (Flagyl), an antimicrobial agent, along
with with bismuth subsalicylate bismuth subsalicylate (Pepto-Bismol) (Pepto-Bismol) and and
tetracyclinetetracycline (antimicrobial) (antimicrobial)
–for 4 weeks to eradicate for 4 weeks to eradicate Helicobacter pyloriHelicobacter pylori

19. Metoclopramide (Reglan) Metoclopramide (Reglan)
A drug that A drug that stimulates the motility of the upper stimulates the motility of the upper
GI tract without stimulating the production of GI tract without stimulating the production of
gastricgastric, biliary, or pancreatic solutions, biliary, or pancreatic solutions
ActionAction
–Increases peristalsis Increases peristalsis in the duodenum and jejunumin the duodenum and jejunum
–Decreases gastroesophageal refluxDecreases gastroesophageal reflux

20. Metoclopramide (Reglan)Metoclopramide (Reglan)
Adverse effectsAdverse effects
–Produces extrapyramidal (Parkinson-like Produces extrapyramidal (Parkinson-like
symptoms) effectssymptoms) effects
–Central nervous system depressionCentral nervous system depression
–Gastrointestinal upsetGastrointestinal upset

21. Summary of Antacid ProductsSummary of Antacid Products
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