Mixed Bag Flashcards
Name the GI Motility Inhibitors
Opiates and Anticholinergics
- diphenhydramine and atropine (Lomotil)
- loperimide (Immodium)
MOA; slows intestinal motility
AE; Sedation; dry mouth; constipation
Bulk formers
- psyllium (Metamucil) - decreases fluidity of stool; absorbs water and forms mass
Laxative Issues
often abused because misconception about daily stool
Three laxative examples
psyllim (metamucil)
methylcellulose (Citrucel)
polycarbophil (Fibercon)
MOA; absorbs water and forms a soft bulky mass
- best for long term use and not acute constipation
-72 hours to work
-must give with water
-bloating and flatus common
docusate sodium (Colace)
MOA: lowers surface tension and allows water to penetrate into stool; softens stools
- main value is to prevent straining
Name stimulant laxatives (3)
bisacodyl (Dulcolax)
senna (Senokot)
phenolphthalein (Ex-Lax)
MOA; stimulate GI motility and pull water into bowel.
Stimulant laxative considerations
Produces fluid stool in:
-PO 6-12 hours
-suppository 15-60 minutes
most abused laxatives causing elyte imbalance
- do not use longer than a week
Saline Cathartics
polyehtylene glycol elyte solution (golytely)
PEG 3350 miralax
Mg Citrate
Lactulose
Used to excrete ammonia from chronic liver disease
lubiprostone (Amitiza)
Notconsidered alaxative
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Adults ONLY: Tx ofchronicidiopathicconstipation inadults&IBS(irritable bowelsyndrome)
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Impacts chloride channels;increasingintestinalfluid secretion &motility
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Fairlywell tolerated except nausea is sometimes aproblem
linaclotide (Linzess)
Activates guanylate cyclase-C, stimulating cGMPproduction&increases intestinalfluidsecretion & motility
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Adults ONLY: chronicconstipation &IBS(irritable bowel syndrome)
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QDdosing; take 30minbefore breakfast (taking withfood may cause loose stools)
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AEs: abdcramping, diarrhea, abddistention
Antiemetic Centers and focus
Phenothaizines used as antiemetics
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Common Drugs:
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promethazine(Phenergan)
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prechlorperazine(Compazine)
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MOA:
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Decrease responseoftheCTZ byinhibitingdopaminergicreceptors
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AE:
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Sedation
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Anticholinergiceffects
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Hypotension
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Extrapyramidaleffects athighdoses-rare(dyskinesias–slowrhythmicalmovements; dystonia–facialgrimace,torticollis)
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Black Box Warning: contraindicated in children < 2yo due to respiratory depression
Phenothaizine black box warning
Not given to children less than two; does not work on motion sickness
antihistamines & anticholinergics for N/V
Common Drugs:
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diphenhydramine(Benadryl)
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dimenhydrinate(Dramamine)
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hydroxyzine(Vistaril)–goodforanxiety,sleep,itching
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meclizine(Antivert)–goodformotionsickness
* scopolamine(TransDermScop)– (anticholinergic)changeq3days;applybefore travel
* MOA:
* Blockhistamineandcholinergicreceptorsprojectingtothevomitingcenter
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Best agentsof motionsickness
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AE:
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Drowsiness
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Anticholinergic(blurred vision, urinary retention, dry mouth,constipation, confusion)
Selective Serotonin Agonist used for N/V
ondansetron (Zofran)
MOA; Blocks serotonin 5-HT3 receptors
Prokinetic Agents - Example and MOA
metoclopramide (Reglan)Common Drugs:
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diphenhydramine(Benadryl)
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dimenhydrinate(Dramamine)
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hydroxyzine(Vistaril)–goodforanxiety,sleep,itching
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meclizine(Antivert)–goodformotionsickness
* scopolamine(TransDermScop)– (anticholinergic)changeq3days;applybefore travel
* MOA:
* Blockhistamineandcholinergicreceptorsprojectingtothevomitingcenter
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Best agentsof motionsickness
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AE:
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Drowsiness
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Anticholinergic(blurred vision, urinary retention, dry mouth,constipation, confusion)
N/V; Antiemetics - corticosteroids
dexamethasone (Decadron)
Peptic Ulcer Disease Overview
PUD Continued
Antacids
MOA; Raise pH above 3.5 in order to prevent conversion of pepsinogen to pepsin
Antacids AE
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Antacids
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AE:
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Diarrhea (magnesium)
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Constipation (calcium & aluminum )
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Rebound hyperacidity (calcium)
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Hypermagnesium (magnesium…avoid in renal failure patients)
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Sodium retention (ie, baking soda, alka‐seltzer effervescent tab…caution with hypertension & HF)
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Considerations:
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separate from other meds by 2 hours
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liquids preferred (increase surface area; chew tablets)
H2 Receptor Antagonist Common Drugs
Common Drugs:*
cimetidine (Tagamet) – interactions with P‐450; many drug‐drug interactions
* famotidine (Pepcid)
* ranitidine (Zantac)
Proton pump inhibitors
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Binds with H, K, ATPase to prevent the “pumping” or release of gastric acidinto the stomach lumen & therefore blocks the final step in acidproduction
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Suppresses gastric acid secretion in response to all primary stimuli(histamine, gastrin, & acetylcholine)
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Strong inhibitor of gastric acid secretion
Common PPI
omeprazole (Prilosec)
pantoprazole (Protonix)
lansoprazole (Prevacid)
PPI MOA
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Binds with H, K, ATPase to prevent the “pumping” or release of gastric acidinto the stomach lumen & therefore blocks the final step in acidproduction
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Suppresses gastric acid secretion in response to all primary stimuli(histamine, gastrin, & acetylcholine)
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Strong inhibitor of gastric acid secretion
PPI Considerations
Considerations:
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Ideally should be taken 30‐60 min prior to other medications, breakfast or evening meal
* Warnings:
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increased risk of osteoporosis & fractures (esp high dose, long‐term, >50 yo, female & other risk factors)
* Due to calcium needs an acidic environment for optimal absorption
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may cause hypomagnesium (esp long‐term use >1 yr)
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may predispose to c diff (long‐term use)
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May also interfere with absorption of iron & vitamin B12 (due to acidic environment needed for optimal absorption)
sucralfate (Carafate)
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MOA:
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An aluminum sucrose complex which binds to damaged tissue forming aprotective barrier that promotes healing
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Does NOT alter acidity; mechanical barrier only!
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Give on empty stomach 1 hour before meals & HS (admin multiple times/day)
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Can decrease absorption of other meds; should be taken alone
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Can cause constipation
Prostaglandin E1 Analog
Prostaglandins E produced in mucosal cells of the stomach & duodenum, inhibitis gastric acidsecretion, increases mucous & bicarb and increases mucosal blood flow
misoprostal (Cytotec)
- MOA:
Enhances mucosal barrier by stimulating mucus and bicarbonate secretion. Used for NSAID induced injury to stomach.
Replaces protective prostaglandins which are used with NSAID therapy
Used with high risk pts: using high doses NSAIDs, >65 yo, hx GI bleed
*AE:
Diarrhea
Contraindicated in pregnancy (category X) –stimulate uterine contractions
H pylori Rx
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Combination therapy of at least:
2 antibiotics PLUS
1 acid suppressor (PPI or H2 blocker)
Usually 14 days
Ex:
PPI BID +
Clarithromycin BID +
Amoxicillin BID
GERD
- Antacids
- H2 blockers
- PPIs
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Treatment of choice
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Take in am before breakfast
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If insufficient response, add second dose prior to dinner
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Prokinetic agents
Explain reverse transcriptinase
Cimetidine side effects
-impotence and swelling of the breasts
-increased prolactin release
- inhibition of CYP450 enzymes which slow the metabolism of many drugs (warfarin & propranolol)
