medications alterations in gastro intestinal

Unit Prototype: Famotidine

Class:

H2 receptor antagonist (H2 blocker)

Unit Prototype: Omeprazole

Class

Class: Proton pump inhibitor (PPI)

MOA: Irreversibly binds to and inhibits the H+/K+ ATPase (proton pump) in gastric parietal

cells, blocking the final step of acid production. More potent and longer-lasting acid suppression

than H2 blockers.

Use: GERD, peptic ulcer disease, H. pylori eradication (as part of combo therapy), erosive

esophagitis, Zollinger-Ellison syndrome.

Adverse/Side Effects: Long-term use risks: increased fracture risk (calcium malabsorption), vitamin B12 deficiency, hypomagnesemia, increased risk of C. diff infection and pneumonia.

Nursing Implications: Give before meals, usually breakfast, for best effect. Monitor for

long-term use and consider periodic reassessment of need. Watch for signs of magnesium or B12

deficiency with prolonged therapy.

Patient Education: Take before eating, swallow capsule whole (don't crush/chew

extended-release forms). Don't stop abruptly if on long-term therapy (can cause rebound acid

hypersecretion). Report black stools, difficulty swallowing, or persistent diarrhea.

Unit Prototype: Antacids

class and MOA

Class: Acid-neutralizing agent (e.g., calcium carbonate, aluminum hydroxide, magnesium

hydroxide combinations)

MOA: Directly neutralize existing stomach acid by reacting with hydrochloric acid, raising gastric pH. Doesn't reduce acid production, just neutralizes what's already there.

Use: Quick relief of heartburn, acid indigestion, and mild GERD symptoms.

Adverse/Side Effects: Aluminum-containing ones cause constipation; magnesium-containing

ones cause diarrhea; calcium carbonate can cause constipation and, in excess, milk-alkali

syndrome. Can cause acid rebound with overuse.

Nursing Implications: Separate administration from other oral medications by at least 1-2 hours

since antacids can bind drugs and reduce absorption. Monitor bowel patterns with regular use.

Patient Education: Use for quick symptom relief, not a substitute for treating an underlying

condition. Take other medications 1-2 hours apart from antacids. Don't exceed the recommended

dose or duration without checking with a provider.

Unit Prototype: Psyllium

class and MOA

Class: Bulk-forming laxative (fiber supplement)

MOA: Absorbs water in the intestine, forming a gel-like bulk that increases stool volume and

softness, which stimulates peristalsis. Considered the most "natural" laxative type.

Use: Constipation, maintenance of regular bowel function, sometimes used for irritable bowel

syndrome and to help lower cholesterol.

Adverse/Side Effects: Bloating, gas, abdominal cramping. Risk of bowel or esophageal

obstruction if not taken with enough fluid.

Nursing Implications: Always give with a full glass of water (at least 8 oz) and encourage

adequate fluid intake throughout the day. Not for use in patients with bowel obstruction.

Patient Education: Mix with a full glass of water or juice and drink right away; don't let it sit

and thicken. Drink plenty of fluids throughout the day. Effects may take 12-72 hours; this isn't a

fast-acting option.

Unit Prototype: Docusate Sodium

class and MOA

Class: Stool softener (emollient laxative)

MOA: Lowers surface tension of the stool, allowing water and fats to penetrate and soften it,

making it easier to pass without straining.

Use: Prevention of constipation, especially in patients who should avoid straining (post-op,

post-MI, postpartum).-

-

-

Adverse/Side Effects: Mild abdominal cramping, throat irritation (liquid form), generally well

tolerated.

Nursing Implications: This is a preventive/softening agent, not a treatment for existing severe

constipation. Encourage fluid intake alongside it.

Patient Education: This softens stool but doesn't stimulate bowel movements; don't expect

immediate urgency. Take with a full glass of water. If liquid form, mix with juice or milk to mask

taste.

Unit Prototype: Bisacodyl

class and MOA

Class: Stimulant laxative

MOA: Directly stimulates sensory nerve endings in the intestinal wall, increasing peristalsis, and

alters fluid/electrolyte transport to increase water content in the colon.

Use: Short-term relief of constipation, bowel prep before procedures.

Adverse/Side Effects: Abdominal cramping, diarrhea, electrolyte imbalance with overuse,

laxative dependence with chronic use.

Nursing Implications: Should not be used long-term due to dependence risk. Do not give within

1 hour of antacids or milk (can dissolve the enteric coating early, causing stomach irritation).

Monitor bowel function and electrolytes with frequent use.

Patient Education: Swallow tablets whole; don't crush or chew (enteric coated to prevent

stomach irritation). Don't take with milk or antacids. Works within 6-12 hours (oral) or 15-60

minutes (suppository). Not for regular long-term use.

Unit Prototype: Magnesium Hydroxide

Class: Saline/osmotic laxative (also used as an antacid at lower doses)

MOA: Draws water into the intestinal lumen through osmosis, increasing stool bulk and

stimulating peristalsis. At lower doses, acts as an antacid by neutralizing gastric acid.

Use: Constipation (as "Milk of Magnesia"), occasional heartburn relief at lower doses.

Adverse/Side Effects: Diarrhea, abdominal cramping, electrolyte imbalances

(hypermagnesemia), especially with renal impairment.

Nursing Implications: Use cautiously in patients with renal impairment, magnesium can

accumulate and cause toxicity (hypotension, respiratory depression, cardiac arrest in severe

cases). Monitor bowel patterns and renal function.

Patient Education: Drink a full glass of water with each dose. Expect a bowel movement within

30 minutes to 6 hours. Report muscle weakness or irregular heartbeat, which could suggest

magnesium buildup.

Unit Prototype: Polyethylene Glycol (PEG, e.g., MiraLAX)

Class: Osmotic laxative

MOA: Holds water in the stool through osmosis without being absorbed or significantly altering

electrolytes, softening stool and increasing frequency of bowel movements.

Use: Occasional or chronic constipation, bowel prep before colonoscopy (higher-dose

formulations).

Adverse/Side Effects: Bloating, gas, abdominal cramping, nausea. Generally well tolerated with

minimal electrolyte disturbance compared to other osmotics.

Nursing Implications: Considered a gentler, first-line option for chronic constipation

management. Monitor effectiveness; onset is typically 1-3 days for standard dosing.

Patient Education: Mix powder completely in 4-8 oz of water or juice before drinking. Can take

up to a few days to work for regular dosing. Drink plenty of fluids

Unit Prototype: Diphenoxylate (usually with atropine, e.g., Lomotil)

Class: Antidiarrheal, opioid agonist

MOA: Acts on opioid receptors in the GI tract to slow intestinal motility and peristalsis, allowing

more water reabsorption and firmer stool. Atropine is added in subtherapeutic doses to discourage

abuse/overdose.

Use: Acute, nonspecific diarrhea.

Adverse/Side Effects: Drowsiness, dizziness, dry mouth (from atropine component),

constipation, risk of toxic megacolon if used in infectious diarrhea, CNS depression, physical

dependence with long-term/high-dose use.

Nursing Implications: Do not use in diarrhea caused by certain infections (e.g., C. diff, invasive

bacteria) because slowing motility can worsen toxin retention. Monitor bowel sounds and

hydration status.

Patient Education: Don't use for more than 48 hours without checking with a provider. Avoid

alcohol and other CNS depressants. Report severe abdominal pain, fever, or blood in stool.

Unit Prototype: Loperamide

Class: Antidiarrheal, opioid agonist (non-CNS penetrating)

MOA: Binds opioid receptors in the intestinal wall, slowing peristalsis and increasing

water/electrolyte absorption. Doesn't cross the blood-brain barrier well at normal doses, so it has

minimal CNS/analgesic effects compared to diphenoxylate.

Use: Acute and chronic diarrhea, including traveler's diarrhea and IBS-related diarrhea.

Adverse/Side Effects: Constipation, abdominal cramping, dizziness, dry mouth. High doses

(misuse) can cause serious cardiac arrhythmias (QT prolongation).-

-

Nursing Implications: Assess the cause of diarrhea before administering; avoid in bacterial

diarrhea with high fever or blood in stool. Monitor for resolution of symptoms and hydration

status.

Patient Education: Don't exceed the recommended dose; high doses can cause dangerous heart

rhythm problems. Stop and seek care if diarrhea persists beyond 48 hours, or if fever/blood in

stool develops. Stay hydrated.

Unit Prototypes: Probiotics/Lactobacillus

Class: Biologic/dietary supplement (live microorganisms)

MOA: Restores or supports normal gut flora, which can help outcompete pathogenic bacteria,

support the intestinal mucosal barrier, and aid digestion.

Use: Prevention/treatment of antibiotic-associated diarrhea, general GI health support, sometimes

used for IBS symptom management.

Adverse/Side Effects: Generally well tolerated; mild gas or bloating. Rare risk of infection in

immunocompromised patients.

Nursing Implications: Use caution in immunocompromised or critically ill patients due to rare

infection risk. Not a treatment for acute severe diarrhea or infection on its own.

Patient Education: Take as directed, often with or after meals. If taking with antibiotics, space

doses apart by a couple of hours to preserve effectiveness. Store according to package directions

(some require refrigeration).