NR 565 Week 7 & 8 Final Exam Study Guide Latest Update 2022/2023
NR 565 Exam Final Study Guide
Antacids: weak bases that react with hydrochloric
... [Show More] acid to form salt & water.
o Used in the treatment of Hyperacidity, GERD, PUD, hyperphosphatemia, and calcium defciency
o Contain combinatons of
metallic caton (aluminum, calcium, magnesium, and sodium)
and basic anion (hydroxide, bicarbonate, carbonate, citrate, and trisilicate)
Pharmacodynamics, Pharmacokinetcs, Pharmacotherapeutcs
o Neutralize Gastric Acidity (causes ^pH of the stomach and duodenal bulb)
o Inhibit proteolytc actvity of pepsin
o Increase lower esophageal sphincter tone
o Acid-neutralizing capacity ANC varies between products expressed in mEqs
o If ingested in a fastng state, antacids reduce acidity for approximately 20 to 40 minutes
o If taken 1 hr afer a meal, acidity is reduced for 2 to 3 hrs
o A second dose taken afer a meal maintains reduced acidity for more than 4 hrs afer the meal
o The acton of antacids occurs locally in the GI tract with minimal absorpton, 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
preparaton
-Concurrent administraton with enteric-coated drugs, destroys the coatng= alters absorpton, ^ the risk for
adverse effects
-Administratons should be separated by at least 2 hours to decrease drug/drug interactons
1. Calcium based antacids: TUMS, Caltrate, Calcarb
Prescribed to treat calcium defcient states, i.e. chronic renal failure, post-menopause, and osteoporosis
Used to bind phosphates in CRF
Require Vitamin D for absorpton from the GI tract
Excreted mainly in feces, 20% in urine
ADR: Contraindicated in the presence of hypercalcemia and renal calculi
Can cause constpaton- increase bulk, fluids and mobility, stool sofener
Administered 30min- 1hr on empty stomach or 3hr afer meals
Should not be administered with food containing large amounts of oxalic acid (spinach, rhubarb), or
phytc acid (bran, cereals), they decrease the absorpton 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 absorpton
2. Aluminum based: AlternaGEL, Amphojel, Mylanta
Inhibit smooth muscle contracton and slow gastric emptying
Used to bind phosphates in CRF
Not absorbable with routne use
Aluminum concentrated in the CNS
Bind with phosphate and excreted in feces
Prolonged use in patents with renal failure may result in dialysis osteomalacia
o Aluminum deposits in bone and osteomalacia occurs
Elevated aluminum tssue levels contribute to the development of dialysis encephalopathy
Used to treat hyperphosphatemia in pts w/ renal failure & phosphate renal stone preventon
Can cause constpaton- increase bulk, fluids and mobility, stool sofener
3. Magnesium based: Milk of mag, Maalox, Mylanta
Aluminum is not easily
removed by dialysis b/c
it is bound to albumin
& transferrin = do not
cross dialysis
membrane Can be used to treat magnesium defciencies from malnutriton, alcoholism, or mag-depletng drugs
Contraindicated in patents with renal failure & used with cauton in pts with renal insufciency
Not absorbable with routne use
Excreted in the urine
Contraindicated in patents with renal failure, use with cauton for patents with any degree of renal
insufciency
o Malfunctoning kidney is unable to excrete magnesium and hypermagnesemia may result
Can cause diarrhea- increase fber intake (Alkalosis may occur in renal impairment)
Clinical Use and Dosing
The malfunctoning
kidney cannot
excrete magnesium=
hypermagnesemia
may result Ratonal drug selecton
o ANC, sodium content, and cost
o Combinaton 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 patents with renal failure or the elderly
with decreased renal functon
Patent educaton
o Take as prescribed, especially related to mealtmes
o Take 1-3 hrs afer meals and at bedtme
o Chewable tablets chew thoroughly and drink half a glass of water
o Shake suspensions before administraton
o Many drug interactons, 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 phytc acid (brans, cereals) decrease absorpton
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 constpaton: increase bulk, increase fluid intake, and more
mobility, stool sofened
o Magnesium antacids may cause diarrhea, increase fber
o Avoid smoking, avoid flat lying body positon while sleeping, foods that irritate the gastric mucosa (spicy
foods), or stmulate acid producton (alcohol) and foods that decrease lower esophageal sphincter tone
(caffeine, chocolate, faty foods) Antdiarrheals:
Diarrhea that lasts for less than 2 weeks is considered acute; if it lasts more than 2 weeks, it is considered chronic.
Pharmacodynamics, Pharmacokinetcs
Three main classes absorbent preparatons (kaolin and pectn (Kapectolin) and bismuth subsalicylate (PeptoBismol, Kaopectate Liquid), opiates (diphenoxylate with atropine (Lomotl), diphenoxin with atropine (Motofen),
and loperamide (Imodium)) and antcholinergics (IBD)
Contraindicatons: Drugs that decrease gastric motlity or delay intestnal transit tme have induced toxic
megacolon, especially in those with inflammatory bowel disease
All antdiarrheals (except Crofelemer) require cautous use in older adults and when there is r/f impacton
Older adults are especially sensitve to diphenoxylate or difenoxin r/t atropine and antcholinergic propertes
Not recommended for children under 12, none of the antdiarrheals are safe for children under 2 years old
Antdiarrheals are contraindicated in the Tx of diarrhea in most children
Standard of care: oral rehydraton therapy
ADRS Rebound constpaton is the main adverse effect
-Kaolin-pectn (kapectolin): Acute diarrhea
Kaolin is a clay-like powder that atracts and holds onto bacteria
Pectn 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
Antsecretory and antmicrobial effects
Also used as part of a multdrug regimen for H. pylori
Undergoes chemical dissociaton 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 afer recovery from chickenpox or flu-like illness
Contraindicated for patents with ASA hypersensitvity
For bismuth subsalicylate, additonal reactons that all patents should be warned about are gray/black
stools and black tongue, the results of the bismuth. Patents should be told to expect this reacton and
that it does not indicate GI bleeding.
Bismuth subsalicylate may potentate the risk for toxicity if taken w/ aspirin
R/f hypoglycemia in large doses with insulin or oral hypoglycemics
-Crofelemer (fulyzaq): Symptomatc relief of noninfectous diarrhea in adult pts w/ HIV/AIDS on antretroviral therapy
Botanical blocking chloride secreton from the epithelial cells in the intestnal lumen, decreasing water loss
and normalizing the flow of chloride and water in the intestnal tract
Minimal absorpton afer PO administraton
Metabolism and excreton are not known
In clinical trials more likely to have URI, bronchits, and cough than placebo group
Adverse GI effects flatulence, increased bilirubin, and nausea
-diphenoxylate w/atropine (Lomotl): Acute diarrhea
Constpatng meperidine congener, lacks analgesic actvity
At high doses can produce euphoria and physical dependence
Antcholinergics are useful only with inflammatory bowel disease
Well absorbed from GI tract The atropine crosses the BBB (produces mild to moderate antcholinergic effects)
Rapidly and extensively metabolized to diphenoxylic acid (it’s metabolite)
Excreted in urine and feces
The atropine component of diphenoxylate and difenoxin contraindicates their use in narrow-angle
glaucoma and requires cautous use in prostatc hyperplasia.
Children, especially those with Down syndrome have increased sensitvity to atropine
Use with extreme cauton in children, not recommended for use in children younger than 12 y/o
Do not use with E. Coli, Salmonella, Shigella, or in pseudomembranous colits
ADRs: r/t atropine: antcholinergic effects (dry mouth, flushing, tachycardia, urinary retenton)
o Crosses BBB=dizziness, drowsiness, sedaton, HA, euphoria, or depression
Additve or potentatng CNS effects with other CNS depressants and additve antcholinergic effects with
other drugs that share these effects
-Difenoxin w/atropine (Motofen): Acute diarrhea9*****
Antcholinergics are useful only with inflammatory bowel disease
Rapidly metabolized to an inactve hydroxylated metabolite
Excreted mainly as conjugates in urine and feces
The atropine component of diphenoxylate and difenoxin contraindicates their use in narrow-angle
glaucoma and requires cautous use in prostatc hyperplasia.
Children, especially those with Down syndrome have increased sensitvity to atropine
Use with extreme cauton in children, not recommended for use in children younger than 12 y/o
Do not use with E. Coli, Salmonella, Shigella, or in pseudomembranous colits
ADRs: r/t atropine: antcholinergic effects (dry mouth, flushing, tachycardia, urinary retenton)
o Crosses BBB=dizziness, drowsiness, sedaton, HA, euphoria, or depression
Additve or potentatng CNS effects with other CNS depressants and additve antcholinergic effects with
other drugs that share these effects
-Loperamide (Imodium): Acute diarrhea, travelers’ diarrhea, chronic diarrhea associated w/inflammatory bowel disease
Binds to opiate receptors of the intestnal wall, slows gastric motlity
Reduces fecal volume, increases viscosity and bulk, diminishes loss of fluid and electrolytes
Does not cross BBB, limited CNS ADRs
Partally metabolized by the liver and undergoes enterohepatc recirculaton to be completely metabolized
Eliminated in feces
ADRs: r/t atropine: antcholinergic effects (dry mouth, flushing, tachycardia, urinary retenton)
o To a lesser degree than diphenoxylate and difenoxin
o Dizziness and drowsiness (less CNS effects than difenoxin or diphenoxylate
Additve or potentatng CNS effects with other CNS depressants and additve antcholinergic effects with other
drugs that share these effects
Pharmacotherapeutcs
Precauton and contraindicatons
Drugs that reduce intestnal motlity or delay intestnal transit tme may cause toxic megacolon, especially in IBD
Diphenoxylate with atropine difenoxin with atropine, and loperamide should be used cautously in IBD
o D/C if ABD distension occurs
Use Diphenoxylate with atropine difenoxin with atropine, and loperamide use with cauton in advanced
hepatorenal disease and in all patents with abnormal LFTs (hepatc coma may occur)
Atropine: contraindicated in narrow-angle glaucoma and requires cautous use in prostatc hyperplasia
Children (especially those with Downs syndrome) have increased sensitvity to atropine
Clinical Use and DosingSimple, Acute Diarrhea
Absorbent preparatons for adults: Kaolin-pectn or bismuth subsalicylate taken afer each loose stool may be
effectve
Majority of acute diarrhea are self-limitng, hydraton important
Maintain hydraton
o Commercial hydratng fluids (Pedialyte) or powdered salts
o A pinch of table salt and a half-teaspoon of honey in 8 oz of fruit juice (older children and adults)
o Non-diet colas without carbonatons (older children and adults)
o Alternate these solutons with 8 oz of water with one-quarter teaspoon baking soda to replenish
electrolytes (NA, K, bicarbonate, and Cl)
If the absorbents do not resolve the problem, diphenoxylate or difenoxin or loperamide may be added
Chronic Diarrhea Associated with IBD
Steroids and sulfasalazine are needed
Loperamide may be used as adjunct therapy
o May signifcantly improve symptoms especially with added fber and antcholinergics
o If clinical improvement does not occur with doses of 16 mg/day for 10 days, symptoms are unlikely
to be controlled by further use
Chronic Diarrhea Associated with Pancreatc Insufciency
Malabsorpton r/t pancreatc insufciency requires enzyme supplements, antdiarrheals not indicated
Chronic Infantle Diarrhea
Bismuth subsalicylate: 2.5 mL every 4 hrs for children 2 to 24 months, 5 mL for 24-48 month children, and 10 mL
for children 48 to 70 months
Diarrhea in HIV/AIDS Patents Taking Antretroviral Drugs
Crofelemer (Fulyzaq) symptomatc relief of noninfectous diarrhea in adults with HIV/AIDS on ARV therapy
125 mg tablet twice a day without regard for food
Traveler’s Diarrhea
Bismuth subsalicylate: two tablets or 2 Fl oz before each meal and at bedtme (QID) for up to 3 weeks
Preventon and treatment
High-risk areas: Central and South American, Africa, Middle East, Mexico, and Asia
E. Coli is the most common causatve agent followed by Campylobacter, Shigella, and Salmonella
Ratonal Drug Selecton
Indicaton: Acute diarrhea, any of the antdiarrheals are appropriate
Subsalicylate and loperamide are the only drugs indicated for traveler’s diarrhea
Loperamide is the only drug with an indicaton for IBD
Generic and brand name formulatons available
Monitoring: No specifc monitoring
Patent Educaton
Take as directed, do not double doses, do not exceed max number of doses in 24 hrs
Notfy provider if diarrhea contnues beyond 48 hrs or if ABD pain, fever, or distenton occurs
Use calibrated measuring devices for liquids, shake suspensions before measured Drug interactons may occur, especially with diphenoxylate and loperamide
Do not take any OTC antdiarrheal before contactng your provider if taking digoxin, cephalosporin antmicrobials,
warfarin or heparin, or CNS depressants (including ETOH)
R/f salicylate poisoning if taking ASA and bismuth subsalicylate
R/f rebound constpaton
Stop drug when s/s of diarrhea are reduced
Bismuth subsalicylate can turn the tongue and stools gray/black
Drugs with atropine: dry mouth, flushing, tachycardia, and urinary retenton
Loperamide also exhibits these reactons but to a lesser degree, add fber and use oral rehydratng solutons
GHWT
Bland food diet, remove milk, could it be lactose intolerance? Cytoprotectve Agents:
o Agents used to treat or prevent ulcer formaton
o Two drugs sucralfate (Carafate) and misoprostol (Cytotec)
Pt should report onset of black tarry stools or severe abdominal pain, which may indicate treatment
failure and GI bleeding
Sucralfate (Carafate):
Pharmacodynamics-Basic aluminum salt that binds to necrotc ulcer tssue where it acts as a barrier to acid,
pepsin, and bile salts.
o Acton is largely topical, no acid-neutralizing actvity, litle is absorbed
o May directly absorb bile salts and stmulate endogenous prostaglandin synthesis (formaton of protectve
mucosa)
Pharmacokinetcs
Minimal absorpton, acton is largely topical
Essentally not absorbed, 90% excreted in feces
Pharmacotherapeutcs
No specifc precautons or contraindicatons
Pregnancy Category B
Safety in children not established
ADRs Minor and rare: constpaton, dizziness, gastric discomfort
Drug/Drug interactons: Decrease absorpton of other drugso Separate administraton of interactng drugs by 2 hours, give other drug frst
Take on an empty stomach
Causes constpaton- increased fluids, dietary bulk, and exercise
Do not use with digoxin or warfarin= decreases effectveness
Indicaton for actve duodenal ulcer x8wks and maintenance afer healing x2wks
Misoprostol (Cytotec):
Pharmacodynamics: A methyl analogue of prostaglandin E1
Inhibits gastric secreton through inhibiton of histamine-stmulated cyclic adenosis monophosphate (AMP)
producton
Inhibits basal and nocturnal gastric acid secreton and acid secreton in response to stmuli
o meals, histamine, and coffee by binding to prostaglandin E receptors, mucosal protectve qualites.
Mucosal protectve qualites as well
o Binds to prostaglandin E receptors which facilitate mucus and bicarbonate producton
Can be taken with food and stll be effectve
Pharmacokinetcs
Rapidly and extensively absorbed afer PO administraton (distributon unknown)
Rapidly converted into a free acid
Does not affect CYP450 system
Half-life is 20-40 mins however renal impairment doubles its half-life
Metabolite excreted in urine
Pharmacotherapeutcs
Use with cauton with cauton in renal impairment (no routne adjustments)
Use with cauton in the elderly r/t decreased renal functon
Pregnancy X: Can produce uterine contractons endangering pregnancy causing spontaneous aborton, premature
birth, or birth defects. Women of childbearing age should have a negatve pregnancy test before prescribed and start
misoprostol on day 2 or 3 of menstrual period. If pregnancy is suspected, drug should be stopped immediately.
ADRs GI or gynecological
o Most common: diarrhea, ABD pain, nausea, and flatulence
o Postmenopausal bleeding, spotng, cramps, hypermenorrhea, menstrual disorder, and dysmenorrhea
Drug/Drug interactons: R/f increased diarrhea when given with magnesium based antacid
Indicated for prophylaxis and treatment of duodenal ulcers associated with NSAID use
Clinical Use and Dosing
Prophylaxis and Treatment of Duodenal Ulcers Associated with NSAID Use
NSAIDs inhibit prostaglandin synthesis and damage the mucosal lining of the stomach
R/f ulcer formaton
Misoprostol is FDA approved for this use (prophylaxis or treatment)
Dosage 200 mcg QID with food ACHS [Show Less]