Acid Controlling Drugs Flashcards
what does the stomach secrete?
Hydrochloric acid (HCl)
Bicarbonate
Pepsinogen
Intrinsic factor
Mucus
Prostaglandins
what are the different glands of the stomach?
Cardiac
Pyloric
Gastric
The cells of the gastric gland are the largest in number and of primary importance when discussing acid control.
wha are the cells of the gastric glands?
Parietal
Chief
Mucous
Endocrine
Enterochromaffin
what does the parietal cells do?
Produce and secrete hydrochloric acid
Primary site of action for many of the drugs used to treat acid-related disorders
what does cheif cells do?
Secrete pepsinogen, a proenzyme
Pepsinogen becomes pepsin when activated by exposure to acid.
Pepsin breaks down proteins (proteolytic
what do mucous cells do?
Mucus-secreting cells (surface epithelial cells)
Provide a protective mucus coat
Protect against self-digestion by hydrochloric acid and digestive enzymes
what does hydrochloric acids do?
Secreted by parietal cells when stimulated by food, caffeine, chocolate, and alcohol
Maintains stomach at pH of 1 to 4
Acidity aids in the proper digestion of food and defenses against microbial infection via the gastrointestinal tract.
Secretion also stimulated by:
Large fatty meals
Emotional stress
what does triple therapy do?
Triple therapy includes a 7- to 14-day course of a proton pump inhibitor (PPI) and the antibiotics clarithromycin and either amoxicillin or metronidazole or quadruple therapy of a PPI, bismuth subsalicylate, and the antibiotics tetracycline and metronidazole.
what are the three types of acid controlling drugs.
Antacids
H2 antagonists
PPIs
what do antiacids do?
- Basic compounds used to neutralize stomach acid
- many antacid preparations also contain the antiflatulent (antigay) drug simethicone..
- many aluminum and calcium-based formulations also include magnesium. constipating effects of aluminum and calcium.
calcium antacids may lead to?
the development of kidney stones and increased gastric and acid secretions.
sodium bicarbonate is a highly?
is a highly soluble antacid form with a quick onset but a short duration of action.
antacids do not?
Do not prevent the overproduction of acid but instead help to neutralize acid secretions
Promote gastric mucosal defensive mechanisms
antacids stimulate the secretions of?
Mucus: protective barrier against hydrochloric acid
Bicarbonate: helps buffer acidic properties of hydrochloric acid
Prostaglandins: prevent activation of proton pump
antacids drug effects?
Reduction of pain and reflux associated with acid-related disorders
- Raising the gastric pH 1 point (1.3 to 2.3) neutralizes 90% of the gastric acid.
- Reducing acidity reduces pain as a result of:
Base-mediated inhibition of the protein-digesting ability of pepsin
Increase in the resistance of the stomach lining to irritation
Increase in the tone of the cardiac sphincter
Antacids: Indications
Acute relief of symptoms associated with peptic ulcer, gastritis, gastric hyperacidity, and heartburn
Antacids: Contraindications
- Known allergy to a specific drug product
- Severe renal failure or electrolyte disturbances: potential toxic accumulation of electrolytes in the antacids themselves
- Gastrointestinal obstruction: Antacids may stimulate gastrointestinal motility when they are undesirable because of the presence of an obstructive process requiring surgical intervention.
antacids OTC
Over-the-counter (OTC) formulations available as:
Capsules and tablets
Powders
Chewable tablets
Suspensions
Effervescent granules and tablets
Types of antacids
Used alone or in combination:
Aluminum hydroxide
Magnesium hydroxide
Simethicone
Combination aluminum hydroxide and magnesium hydroxide contain a local anaesthetic (Mucaine®).
antacids - magnesium salts
Commonly cause diarrhea; usually used with other drugs to counteract this effect
Dangerous when used with renal failure; the failing kidney cannot excrete extra magnesium, resulting in accumulation
Magnesium hydroxide and mineral oil (Magnolox®)
examples of aluminum salts
Combination products (aluminum and magnesium): Antacid Plus®, Diovol®, Gelusil®, Maalox®, Multiaction®
antacids - aluminum salts
Have constipating effects
Often used with magnesium to counteract constipation
Often recommended for patients with renal disease (more easily excreted)
Examples
examples of magnesium salts
Magnesium hydroxide and mineral oil (Magnolox®)
antacids - calcium salts
Many forms but carbonate is most common
May cause constipation, kidney stones
Also not recommended for patients with renal disease—may accumulate to toxic levels
Long duration of acid action—may cause increased gastric acid secretion (hyperacidity rebound)
Often advertised as an extra source of dietary calcium
examples of calcium salts
Example: calcium carbonate and simethicone (Maalox, Rolaids®)
antacids - sodium bicarbonate
Highly soluble
Buffers the acidic properties of hydrochloric acid
Quick onset but short duration
May cause metabolic alkalosis
Sodium content may cause problems in patients with heart failure, hypertension, or renal insufficiency.
Antacids and Antiflatulents
used to relieve the painful symptoms associated with gas
Antacids: Adverse Effects
Minimal and depend on the compound used
- Overuse: metabolic alkalosis
- Aluminum and calcium: constipation
- Magnesium: diarrhea
- Calcium: kidney stones, rebound hyperacidity
- Calcium carbonate: produces gas and belching; often combined with simethicone
Several drugs are used to bind or alter intestinal gas and are often added to antacid combination products an examples would be?
simethicone
atancids drug interactions -Adsorption of other drugs to antacids
Reduces the ability of the other drug to be absorbed into the body
antacids drug interactions - Chelation
Chemical binding, or inactivation, of another drug
Produces insoluble complexes
Result: reduced drug absorption
antacids dug interactions - increased stomach ph
Increased absorption of basic drugs
Decreased absorption of acidic drugs
antacids drug interactiins - increased urinary ph
Increased excretion of acidic drugs
Decreased excretion of basic drugs
H2 Receptor Antagonists
Reduce acid secretion
All available OTC in lower-dosage forms
H2 receptor agonists - Most popular drugs for treatment of acid-related disorders
- ranitidine hydrochloride (Zantac®)
- famotidine (Pepcid®)
H2 Antagonists: Mechanism of Action
Competitively block the H2 receptor of acid-producing parietal cells
Reduce hydrogen ion secretion from the parietal cells
Increase in the pH of the stomach
Relieve of many of the symptoms associated with hyperacidity-related conditions
H2 Antagonists: Drug Effect and Indications
Drug effect:
Suppressed acid secretion in the stomach
Indications:
Gastroesophageal reflux disease (GERD)
Peptic ulcer disease
Erosive esophagitis
Adjunct therapy to control upper gastrointestinal bleeding
Zollinger-Ellison syndrome
H2 Antagonists: Adverse Effects
Overall, very few adverse effects
Central nervous system adverse effects in elderly patients include confusion and disorientation.
Cimetidine may cause erectile dysfunction and gynecomastia.
Thrombocytopenia has been reported with ranitidine hydrochloride and famotidine.
H2 Antagonists: Drug Interactions(1 of 2)
- All H2 antagonists may inhibit the absorption of drugs that require an acidic gastrointestinal environment for absorption.
Because of its potential to cause drug interactions, -cimetidine has been largely replaced by ranitidine and famotidine.
H2 Antagonists: Drug Interactions (2 of 2)
- Smoking has been shown to decrease the effectiveness of H2 blockers.
- For optimal results, H2 receptor antagonists are taken 1 hour before antacids.
Proton Pump Inhibitors do what
The parietal cells release positive hydrogen ions (protons) during hydrochloric acid production.
This process is called the proton pump.
H2 blockers and antihistamines do not stop the action of this pump.
types of proton pump inhibitors, ends with zoles.
lansoprazole (Prevacid®)
omeprazole (Losec®)
pantoprazole sodium (Pantoloc®)
Proton Pump Inhibitors: Mechanism of Action
Irreversibly bind to H+/K+ adenosine triphosphatase (ATPase) enzyme
This bond prevents the movement of hydrogen ions from the parietal cell into the stomach.
Results in achlorhydria—all gastric acid secretion is temporarily blocked.
To return to normal acid secretion, the parietal cell must synthesize new H+/K+ ATPase.
Proton Pump Inhibitors: Indications
Gastroesophageal reflux disease
Erosive esophagitis
Short-term treatment of active duodenal and benign gastric ulcers
Zollinger-Ellison syndrome
Nonsteroidal anti-inflammatory drug (NSAID)–induced ulcers
Stress ulcer prophylaxis
Treatment of H. pylori–induced infections
Given with an antibiotic
Proton Pump Inhibitors: Adverse Effects
Protein pump inhibitors (PPIs) are generally well tolerated.
Possible predisposition to gastrointestinal tract infections: Clostridium difficile
Osteoporosis and risk of wrist, hip, and spine fractures in long-term users
Pneumonia
Depletion of magnesium
Proton Pump Inhibitors: Drug Interactions
Increase serum levels of diazepam and phenytoin
Warfarin: increased chance of bleeding
Absorption of ketoconazole, ampicillin, iron salts, and digoxin
Copidogrel (Plavix): risk of MI, death
Sucralfate: may delay the absorption of PPIs
Food may decrease absorption of the PPIs.
Miscellaneous Acid-Controlling Drugs
sucralfate
misoprostol
Simethicone (Ovol®)
Sucralfate ( know this)
Cytoprotective drug
Used for stress ulcers, peptic ulcer disease.
Attracted to and binds to the base of ulcers and erosions, forming a protective barrier over these areas.
Protects these areas from pepsin, which normally breaks down proteins (making ulcers worse). Little absorption from the gut.
May cause constipation, nausea, and dry mouth.
May impair absorption of other drugs. Give other drugs at least 2 hours before sucralfate.
Do not administer with other medications.
Binds with phosphate; may be used in chronic renal failure to reduce phosphate levels
Misoprostol
Prostaglandin E analogue
Prostaglandins have cytoprotective activity.
Protect gastric mucosa from injury by enhancing local production of mucus or bicarbonate
Promote local cell regeneration
Help to maintain mucosal blood flow. Used for prevention of NSAID-induced gastric ulcers
Doses that are therapeutic enough to treat duodenal ulcers often produce abdominal cramps and diarrhea.
Simethicone
Antiflatulent drug
Used to reduce the discomforts of gastric or intestinal gas (flatulence)
Alters elasticity of mucus-coated gas bubbles, breaking them into smaller ones
Result is decreased gas pain and increased expulsion via mouth or rectum.
Nursing Implications: Antacids
Assess for allergies and pre-existing conditions that may restrict the use of antacids, such as:
Fluid imbalances
Renal disease
Gastrointestinal obstruction
Heart failure
Pregnancy
Patients with heart failure or hypertension should not use antacids with high sodium content.
Nursing Implications: Antacids
Use with caution with other medications because of the many drug interactions.
Administer antacids within 1 to 2 hours of other medications.
Antacids may cause premature dissolving of enteric-coated medications, resulting in stomach upset.
Nursing Implications: Antacids
Be sure that chewable tablets are chewed thoroughly and that liquid forms are shaken well before giving.
Administer with at least 240 mL of water to enhance absorption (except for “rapid-dissolve” forms).
Nursing Implications: Antacids
Long-term self-medication with antacids may mask symptoms of serious underlying diseases, such as malignancy or bleeding ulcers.
If symptoms remain ongoing, the patient should seek medical evaluation.
Nursing Implications: Antacids - adverse effects and therapeutic response.
Monitor for adverse effects.
Nausea, vomiting, abdominal pain, diarrhea
With calcium-containing products: constipation, acid rebound
Monitor for therapeutic response.
Notify the health care provider if symptoms are not relieved.
Nursing Implications: H2 Antagonists
Assess for allergies and impaired renal or liver function.
Use with caution in patients who are confused, disoriented, or in older adult patients.
Take 1 to 2 hours before antacids.
For intravenous doses, follow administration guidelines.
Nursing Implications: Proton Pump Inhibitors
Assess for allergies and history of liver disease.
Not all are available for parenteral administration.
May increase serum levels of diazepam and phenytoin; may increase chance for bleeding with warfarin. The granules of pantoprazole capsules may be given via nasogastric tubes
Capsules may be open and their contents mixed with apple juice, but delayed-release granules are not to be crushed or chewed.
