Acid Neutralization

Question 1

Antacid Mechanism of Action

Answer 1

• Weak bases that neutralize stomach acid
• Act as buffers
• Rapid onset, quick relief of symptoms
• Do not reduce acid production

Question 2

Antacid Indications

Answer 2

• Short term relief of acid related symptoms

Question 3

Magnesium Antacid

Answer 3

• Fast acting
• Osmotic laxative effect = diarrhea
• Risk of hypermagnesemia in renal impairment

Question 4

Aluminum Antacid

Answer 4

• Slower onset
• Causes constipation
• Risk of aluminum accumulation in renal impairment

Question 5

Aluminum/Magnesium Antacid Combination

Answer 5

• Balances bowel effects

Question 6

Calcium Antacid

Answer 6

• Longer effect
• Constipating
• Risk of hypercalcemia
• Stomach responds to acid neutralization with increased gastrin secretion, so acid symptoms may increase after effect wears off

Question 7

Sodium Bicarbonate

Answer 7

• Rapid onset, short duration
• Avoid long term use due to high sodium load
• Avoid in patients with heart failure or other conditions where sodium may increase adverse effects

Question 8

Antacid Interactions

Answer 8

• When gastric pH is increased, pH dependent drugs may undergo altered ionization, thus, altered absorption (basic drugs absorb more readily, acidic drugs absorb less)
• Urine pH is also altered, effecting how drugs are excreted
• Antacids also bind to drugs in the GI tract, decreasing their absorption

Question 9

Nursing Considerations

Answer 9

• Renal impairment: Magnesium and aluminum accumulate, causing neurologic, neuromuscular, and cardiovascular toxicity
• Medication timing: Separate from interacting medications that the antacids will bind to, and teach patients to do the same

Question 10

Proton Pump Inhibitor

Answer 10

• First-line therapy
• Irreversibly bind to hydrogen-potassium-ATPase pump
• Blocks the final step of gastric acid secretion
• Potent and sustained acid suppression, ending only when new proton pumps are synthesized by parietal cells

Question 11

Proton Pump Inhibitor Indications

Answer 11

• Peptic ulcer disease
• GERD
• Zollinger-Ellison Syndrome (acid hypersecretion)
• NSAID-associated ulcers
• Adjunctive therapy for H. pylori eradication

Question 12

Proton Pump Inhibitor Examples

Answer 12

• Prazoles
• Lansoprazole
• Omeprazole
• Pantoprazole
• Esomeprazole

Question 13

Proton Pump Inhibitor Timing

Answer 13

• Must be absorbed into the bloodstream before taking effect, which takes 30-60 min therefore they must be taken before a meal
• Selectively bind to active proton pumps, which are present when food is eaten
• In combination, this means that the drug reaches the bloodstream right as pumps are active for maximal acid suppression

Question 14

Proton Pump Inhibitor Adverse Effects

Answer 14

• Short term effects are uncommon
• Long term use associated with C. diff infection, hypomagnesemia, bone fractures, vit B12 deficiency

Question 15

Proton Pump Inhibitor Nursing Considerations

Answer 15

• Admin before first meal of the day
• Assess GI symptoms throughout therapy

Question 16

H2 Receptor Antagonist Mechanism of Action

Answer 16

• Completely blocks histamine receptors on gastric parietal cells
• Decreases stimulation of the proton pump

Question 17

H2 Receptor Antagonist Indications

Answer 17

• Less commonly used now, may be adjunct or alternative to PPIs
• GERD
• Peptic ulcer disease
• Erosive esophagitis
• Upper GI bleed
• Hypersecretory conditions

Question 18

H2 Receptor Antagonist Examples

Answer 18

Famotidine

Question 19

H2 Receptor Antagonist Nursing Considerations

Answer 19

• Renal Impairment: Famotidine is primarily renally excreted. Accumulation can cause confusion and agitation especially in older adults
• IV Admin: Admin slowly to prevent hypotension and arrhythmia
• Drug Interactions: Increased gastric pH can affect absorption