NR 565 Exam Final Study Guide
Antacids: weak bases that react with hydrochloric acid to form salt & water.
o Used in the treatment of Hyperacidity, GERD, PUD, hyperphosphatemia, and calcium deficiency
o Contain combinations of
metallic cation (aluminum, calcium, magnesium, and sodium)
and basic anion (hydroxide, bicarbonate, carbonate, citrate, and trisilicate)
Pharmacodynamics, Pharmacokinetics, Pharmacotherapeutics
o Neutralize Gastric Acidity (causes ^pH of the stomach and duodenal bulb)
o Inhibit proteolytic activity of pepsin
o Increase lower esophageal sphincter tone
o Acid-neutralizing capacity ANC varies between products expressed in mEqs
o If ingested in a fasting state, antacids reduce acidity for approximately 20 to 40 minutes
o If taken 1 hr after a meal, acidity is reduced for 2 to 3 hrs
o A second dose taken after a meal maintains reduced acidity for more than 4 hrs after the meal
o The action of antacids occurs locally in the GI tract with minimal absorption, minimal metabolism
o ALL antacids are contraindicated in the presence of severe abdominal pain of unknown cause, especially if
accompanied by fever
-HIGH SODIUM content: pts w/ HTN, CHF, marked renal failure, or on low-sodium diets need to use low sodium
preparation
-Concurrent administration with enteric-coated drugs, destroys the coating= alters absorption, ^ the risk for
adverse effects
-Administrations should be separated by at least 2 hours to decrease drug/drug interactions
1. Calcium based antacids: TUMS, Caltrate, Calcarb
Prescribed to treat calcium deficient states, i.e. chronic renal failure, post-menopause, and osteoporosis
Used to bind phosphates in CRF
Require Vitamin D for absorption from the GI tract
Excreted mainly in feces, 20% in urine
ADR: Contraindicated in the presence of hypercalcemia and renal calculi
Can cause constipation- increase bulk, fluids and mobility, stool softener
Administered 30min- 1hr on empty stomach or 3hr after meals
Should not be administered with food containing large amounts of oxalic acid (spinach, rhubarb), or
phytic acid (bran, cereals), they decrease the absorption of calcium
Taking w/ foods containing phosphorus (milk, dairy) can lead to milk-alkali syndrome (N/V, confusion,
headache).
Taking with acidic fruit juice improve absorption
2. Aluminum based: AlternaGEL, Amphojel, Mylanta
Inhibit smooth muscle contraction and slow gastric emptying
Used to bind phosphates in CRF
Aluminum is not easily
removed by dialysis b/c Not absorbable with routine use
it is bound to albumin Aluminum concentrated in the CNS
& transferrin = do not
cross dialysis Bind with phosphate and excreted in feces
membrane Prolonged use in patients with renal failure may result in dialysis osteomalacia
o Aluminum deposits in bone and osteomalacia occurs
Elevated aluminum tissue levels contribute to the development of dialysis encephalopathy
Used to treat hyperphosphatemia in pts w/ renal failure & phosphate renal stone prevention
Can cause constipation- increase bulk, fluids and mobility, stool softener
3. Magnesium based: Milk of mag, Maalox, Mylanta
, Can be used to treat magnesium deficiencies from malnutrition, alcoholism, or mag-depleting drugs
The malfunctioning Contraindicated in patients with renal failure & used with caution in pts with renal insufficiency
kidney cannot
excrete magnesium= Not absorbable with routine use
hypermagnesemia Excreted in the urine
may result
Contraindicated in patients with renal failure, use with caution for patients with any degree of renal
insufficiency
o Malfunctioning kidney is unable to excrete magnesium and hypermagnesemia may result
Can cause diarrhea- increase fiber intake (Alkalosis may occur in renal impairment)
Clinical Use and Dosing
, Rational drug selection
o ANC, sodium content, and cost
o Combination products with aluminum hydroxide and magnesium hydroxide have the highest ANC (use is
moderate to severe disease
Monitoring
o Serum phosphate, potassium, and calcium during chronic use
o These drugs may cause increased serum calcium and decreased serum phosphate
o Chronic magnesium hydroxide use may cause elevated Mg levels in patients with renal failure or the elderly
with decreased renal function
Patient education
o Take as prescribed, especially related to mealtimes
o Take 1-3 hrs after meals and at bedtime
o Chewable tablets chew thoroughly and drink half a glass of water
o Shake suspensions before administration
o Many drug interactions, separate doses by 2 hours apart
o Calcium based antacids should not be administer with food containing large amounts of oxalic acid (spinach,
rhubarb) or phytic acid (brans, cereals) decrease absorption
o Avoid taking with food containing phosphorus (milk, dairy products) can cause milk-alkali syndrome (NV,
confusion, HA)
o Consult provider: before taking antacids for more than 2 weeks if a problem recurs, if relief is not obtained,
or if symptoms of GI bleeding (black, tarry stools, coffee ground emesis
o Aluminum and calcium antacids may cause constipation: increase bulk, increase fluid intake, and more
mobility, stool softened
o Magnesium antacids may cause diarrhea, increase fiber
o Avoid smoking, avoid flat lying body position while sleeping, foods that irritate the gastric mucosa (spicy
foods), or stimulate acid production (alcohol) and foods that decrease lower esophageal sphincter tone
(caffeine, chocolate, fatty foods)
, Antidiarrheals:
Diarrhea that lasts for less than 2 weeks is considered acute; if it lasts more than 2 weeks, it is considered chronic.
Pharmacodynamics, Pharmacokinetics
Three main classes absorbent preparations (kaolin and pectin (Kapectolin) and bismuth subsalicylate (Pepto-
Bismol, Kaopectate Liquid), opiates (diphenoxylate with atropine (Lomotil), diphenoxin with atropine (Motofen),
and loperamide (Imodium)) and anticholinergics (IBD)
Contraindications: Drugs that decrease gastric motility or delay intestinal transit time have induced toxic
megacolon, especially in those with inflammatory bowel disease
All antidiarrheals (except Crofelemer) require cautious use in older adults and when there is r/f impaction
Older adults are especially sensitive to diphenoxylate or difenoxin r/t atropine and anticholinergic properties
Not recommended for children under 12, none of the antidiarrheals are safe for children under 2 years old
Antidiarrheals are contraindicated in the Tx of diarrhea in most children
Standard of care: oral rehydration therapy
ADRS Rebound constipation is the main adverse effect
-Kaolin-pectin (kapectolin): Acute diarrhea
Kaolin is a clay-like powder that attracts and holds onto bacteria
Pectin thickens the stool by absorbing moisture
Used to treat simple diarrhea
Act locally in the bowel, not systemically absorbed
Pregnancy Category B
-Bismuth subsalicylate (Pepto bismol): Acute diarrhea, travelers’ diarrhea
Antisecretory and antimicrobial effects
Also used as part of a multidrug regimen for H. pylori
Undergoes chemical dissociation in GI, salicylate moiety is absorbed
Salicylate is metabolized in the liver and more than 90% is excreted in urine
Contraindicated in children or teenagers during or after recovery from chickenpox or flu-like illness
Contraindicated for patients with ASA hypersensitivity
For bismuth subsalicylate, additional reactions that all patients should be warned about are gray/black
stools and black tongue, the results of the bismuth. Patients should be told to expect this reaction and
that it does not indicate GI bleeding.
Bismuth subsalicylate may potentiate the risk for toxicity if taken w/ aspirin
R/f hypoglycemia in large doses with insulin or oral hypoglycemics
-Crofelemer (fulyzaq): Symptomatic relief of noninfectious diarrhea in adult pts w/ HIV/AIDS on antiretroviral therapy
Botanical blocking chloride secretion from the epithelial cells in the intestinal lumen, decreasing water loss
and normalizing the flow of chloride and water in the intestinal tract
Minimal absorption after PO administration
Metabolism and excretion are not known
In clinical trials more likely to have URI, bronchitis, and cough than placebo group
Adverse GI effects flatulence, increased bilirubin, and nausea
-diphenoxylate w/atropine (Lomotil): Acute diarrhea
Constipating meperidine congener, lacks analgesic activity
At high doses can produce euphoria and physical dependence
Anticholinergics are useful only with inflammatory bowel disease
Well absorbed from GI tract
Antacids: weak bases that react with hydrochloric acid to form salt & water.
o Used in the treatment of Hyperacidity, GERD, PUD, hyperphosphatemia, and calcium deficiency
o Contain combinations of
metallic cation (aluminum, calcium, magnesium, and sodium)
and basic anion (hydroxide, bicarbonate, carbonate, citrate, and trisilicate)
Pharmacodynamics, Pharmacokinetics, Pharmacotherapeutics
o Neutralize Gastric Acidity (causes ^pH of the stomach and duodenal bulb)
o Inhibit proteolytic activity of pepsin
o Increase lower esophageal sphincter tone
o Acid-neutralizing capacity ANC varies between products expressed in mEqs
o If ingested in a fasting state, antacids reduce acidity for approximately 20 to 40 minutes
o If taken 1 hr after a meal, acidity is reduced for 2 to 3 hrs
o A second dose taken after a meal maintains reduced acidity for more than 4 hrs after the meal
o The action of antacids occurs locally in the GI tract with minimal absorption, minimal metabolism
o ALL antacids are contraindicated in the presence of severe abdominal pain of unknown cause, especially if
accompanied by fever
-HIGH SODIUM content: pts w/ HTN, CHF, marked renal failure, or on low-sodium diets need to use low sodium
preparation
-Concurrent administration with enteric-coated drugs, destroys the coating= alters absorption, ^ the risk for
adverse effects
-Administrations should be separated by at least 2 hours to decrease drug/drug interactions
1. Calcium based antacids: TUMS, Caltrate, Calcarb
Prescribed to treat calcium deficient states, i.e. chronic renal failure, post-menopause, and osteoporosis
Used to bind phosphates in CRF
Require Vitamin D for absorption from the GI tract
Excreted mainly in feces, 20% in urine
ADR: Contraindicated in the presence of hypercalcemia and renal calculi
Can cause constipation- increase bulk, fluids and mobility, stool softener
Administered 30min- 1hr on empty stomach or 3hr after meals
Should not be administered with food containing large amounts of oxalic acid (spinach, rhubarb), or
phytic acid (bran, cereals), they decrease the absorption of calcium
Taking w/ foods containing phosphorus (milk, dairy) can lead to milk-alkali syndrome (N/V, confusion,
headache).
Taking with acidic fruit juice improve absorption
2. Aluminum based: AlternaGEL, Amphojel, Mylanta
Inhibit smooth muscle contraction and slow gastric emptying
Used to bind phosphates in CRF
Aluminum is not easily
removed by dialysis b/c Not absorbable with routine use
it is bound to albumin Aluminum concentrated in the CNS
& transferrin = do not
cross dialysis Bind with phosphate and excreted in feces
membrane Prolonged use in patients with renal failure may result in dialysis osteomalacia
o Aluminum deposits in bone and osteomalacia occurs
Elevated aluminum tissue levels contribute to the development of dialysis encephalopathy
Used to treat hyperphosphatemia in pts w/ renal failure & phosphate renal stone prevention
Can cause constipation- increase bulk, fluids and mobility, stool softener
3. Magnesium based: Milk of mag, Maalox, Mylanta
, Can be used to treat magnesium deficiencies from malnutrition, alcoholism, or mag-depleting drugs
The malfunctioning Contraindicated in patients with renal failure & used with caution in pts with renal insufficiency
kidney cannot
excrete magnesium= Not absorbable with routine use
hypermagnesemia Excreted in the urine
may result
Contraindicated in patients with renal failure, use with caution for patients with any degree of renal
insufficiency
o Malfunctioning kidney is unable to excrete magnesium and hypermagnesemia may result
Can cause diarrhea- increase fiber intake (Alkalosis may occur in renal impairment)
Clinical Use and Dosing
, Rational drug selection
o ANC, sodium content, and cost
o Combination products with aluminum hydroxide and magnesium hydroxide have the highest ANC (use is
moderate to severe disease
Monitoring
o Serum phosphate, potassium, and calcium during chronic use
o These drugs may cause increased serum calcium and decreased serum phosphate
o Chronic magnesium hydroxide use may cause elevated Mg levels in patients with renal failure or the elderly
with decreased renal function
Patient education
o Take as prescribed, especially related to mealtimes
o Take 1-3 hrs after meals and at bedtime
o Chewable tablets chew thoroughly and drink half a glass of water
o Shake suspensions before administration
o Many drug interactions, separate doses by 2 hours apart
o Calcium based antacids should not be administer with food containing large amounts of oxalic acid (spinach,
rhubarb) or phytic acid (brans, cereals) decrease absorption
o Avoid taking with food containing phosphorus (milk, dairy products) can cause milk-alkali syndrome (NV,
confusion, HA)
o Consult provider: before taking antacids for more than 2 weeks if a problem recurs, if relief is not obtained,
or if symptoms of GI bleeding (black, tarry stools, coffee ground emesis
o Aluminum and calcium antacids may cause constipation: increase bulk, increase fluid intake, and more
mobility, stool softened
o Magnesium antacids may cause diarrhea, increase fiber
o Avoid smoking, avoid flat lying body position while sleeping, foods that irritate the gastric mucosa (spicy
foods), or stimulate acid production (alcohol) and foods that decrease lower esophageal sphincter tone
(caffeine, chocolate, fatty foods)
, Antidiarrheals:
Diarrhea that lasts for less than 2 weeks is considered acute; if it lasts more than 2 weeks, it is considered chronic.
Pharmacodynamics, Pharmacokinetics
Three main classes absorbent preparations (kaolin and pectin (Kapectolin) and bismuth subsalicylate (Pepto-
Bismol, Kaopectate Liquid), opiates (diphenoxylate with atropine (Lomotil), diphenoxin with atropine (Motofen),
and loperamide (Imodium)) and anticholinergics (IBD)
Contraindications: Drugs that decrease gastric motility or delay intestinal transit time have induced toxic
megacolon, especially in those with inflammatory bowel disease
All antidiarrheals (except Crofelemer) require cautious use in older adults and when there is r/f impaction
Older adults are especially sensitive to diphenoxylate or difenoxin r/t atropine and anticholinergic properties
Not recommended for children under 12, none of the antidiarrheals are safe for children under 2 years old
Antidiarrheals are contraindicated in the Tx of diarrhea in most children
Standard of care: oral rehydration therapy
ADRS Rebound constipation is the main adverse effect
-Kaolin-pectin (kapectolin): Acute diarrhea
Kaolin is a clay-like powder that attracts and holds onto bacteria
Pectin thickens the stool by absorbing moisture
Used to treat simple diarrhea
Act locally in the bowel, not systemically absorbed
Pregnancy Category B
-Bismuth subsalicylate (Pepto bismol): Acute diarrhea, travelers’ diarrhea
Antisecretory and antimicrobial effects
Also used as part of a multidrug regimen for H. pylori
Undergoes chemical dissociation in GI, salicylate moiety is absorbed
Salicylate is metabolized in the liver and more than 90% is excreted in urine
Contraindicated in children or teenagers during or after recovery from chickenpox or flu-like illness
Contraindicated for patients with ASA hypersensitivity
For bismuth subsalicylate, additional reactions that all patients should be warned about are gray/black
stools and black tongue, the results of the bismuth. Patients should be told to expect this reaction and
that it does not indicate GI bleeding.
Bismuth subsalicylate may potentiate the risk for toxicity if taken w/ aspirin
R/f hypoglycemia in large doses with insulin or oral hypoglycemics
-Crofelemer (fulyzaq): Symptomatic relief of noninfectious diarrhea in adult pts w/ HIV/AIDS on antiretroviral therapy
Botanical blocking chloride secretion from the epithelial cells in the intestinal lumen, decreasing water loss
and normalizing the flow of chloride and water in the intestinal tract
Minimal absorption after PO administration
Metabolism and excretion are not known
In clinical trials more likely to have URI, bronchitis, and cough than placebo group
Adverse GI effects flatulence, increased bilirubin, and nausea
-diphenoxylate w/atropine (Lomotil): Acute diarrhea
Constipating meperidine congener, lacks analgesic activity
At high doses can produce euphoria and physical dependence
Anticholinergics are useful only with inflammatory bowel disease
Well absorbed from GI tract
