Exam 4 - GI Constipation Flashcards
Definition of constipation?
Less than 3 BMs per week
Diet and exercise that helps with BMs? Colonic motility?
Fiber, fluid, exercise. Colonic motility increases 2-3x after exercise and meal.
4 broad disorder categories which can cause constipation?
- GI disorders (IBS)
- Metabolic disorders (DM)
- Endocrine disorders (hypothyroidism)
- Neurological disorders (MS, Parkinsons, anxiety, depression
Hydration goal for constipation tx?
8-12 glasses of water per day
Diet and lifestyle issues that can cause constipation? (Hint: 4)
Low fiber Low fluid Inactive lifestyle Preggers Drug induced (opiated)
TCAs, Diphenhydramine, and Antipsychotics are in what class? What can they cause?
Anticholinergics. Cause constipation.
Tx goals for constipation? (Hint: 3)
- Increase frequency of stool movement
- Soften stools
- Prevent recurrence
General rule about constipation meds?
Take a bedtime
When are constipation meds taken?
At night
What class if first-line treatment and prevention of constipation?
Polyethene Glycol PEG
MOA of Stool Softeners? When/who to use in?
Anion surfactant- detergents mixing aqueous and fatty substances to soften fecal mass.
Used to avoid straining s/p MI, surgery, hemorrhoid flare.
“All mush, no push.”
Stool Softener onset? Preventative or treatment or constipation? Example?
1-3 days onset. Prevention of constipation.
Ex: Docusate/Colace
MOA of Lubricants? Onset? Examples? Treatment or prevention of constipation?
Coats stool and prevents absorption of water allowing easier passage. 24h onset. Treatment.
Glycerin, Mineral Oil
Glycerin class? How given? Who to give to? Onset?
Lubricant. Suppository to children. 30 minute onset.
Mineral Oil class? DDI? Don’t give to who?
Lubricant. Can affect fat-soluable vitamins and Warfarin. Don’t give to bed-ridden patient due to aspiration pneumonia.
Bulk Forming MOA? Need to take with what? Time separation when taking other meds? Onset? Who not to use in? SE?
Promote Peristalsis. Must drink water. 1-3 day onset. 1-2 hour separation with other meds. Not in bed-ridden patients. Bloating and gas side-effects.
Are Bulk Forming meds preventative or treatment? Examples? What happens if not eat, drink, and move while on?
Preventative. Psyllium (Fibercon, Metamucil). If no move/eat/drink then turds turn into brick.
MOA of Osmotics? Side-effects? Treatment or prevention of constipation?
Nonabsorbable sugars which pull water into colon, soften stool and increase volume. Increases peristalsis. Cramping, diarrhea, electrolyte imbalance. Prevention and treatment
Major side-effect of Osmotics?
Electrolye imbalance
Example of Osmotic and time to onset? Notable side-effect of one of them?
Lactulose=1-3 days
33% Sorbitol=onset quick but lower K
Saline Cathartic MOA? Onset? Routes?
Nonabsorbable cation and anions pull fluid into GI tract. 6 hour onset. PO and rectal. Use infrequenty!
Magnesium Hydroxide (Milk of Magnesia). Sodium Phosphate.
Saline Cathartic frequency of use? Treatment or prevention of constipation?
Use infrequently (single use in hospital). Treatment of constipation.
What important to do while taking Saline Cathartics? Examples of Saline Cathartics?
Must maintain hydration.
Milk of Magnesia. Sodium Phosphate.
People with Renal impairment, Heart failure, or on Diuretics shouldn’t take which med class?
Saline Cathartics (Milk of Magnesia, Sodium Phosphate)
Saline Cathartics not safe in what three conditions or meds?
- Renal impairment
- Heart failure
- Diuretics
MOA of Electrolyte Solutions? Can prevent what common ADR?
Nonabsorbable osmotically active sugar draws water into intestinal lumen and increases intestinal motility. Contains electrolytes to prevent imbalance. PEG.
Which Electrolyte Solutions used prior to colonoscopy and which for treatment of constipation? Onsets?
Colonoscopy: GoLYTELY, NuLYTELY 1-6 hour onset
Treatment: Miralax PEG 3350, 1-3 day onset
Stimulant MOA? For who?
Directly stimulates intestinal mucosa to increase propulsive activity.
For patients on daily meds which make them chronically constipated.
Stimulant daily use? Given when patient on what other med? Examples?
OK for daily use. Given with narcotics.
Ex: Bisadocyl (Ducolax), Senna (Senokot, Ex-Lax), Cascara Sagrada
What is good for patients on chronic constipating meds?
Stimulants
Secretory MOA? Onset?
Stimulates secretion of fluid into gut. Strong purgative action. Onset 1-3h.
Secretory side-effect? Duration of use? Example?
Electrolyte imbalance. Not for regular use. Castor Oil.
Motility Stimulant MOA? Onset? Rx needed? Example?
Increases colonic motility and shorten transit time. Dopamine antagonist. 6-48h onset.
Ex: Metoclopramide
Motility Stimulant MOA? Indications?
Increase motility time and shorten transit time. Indicated in gastroperesis and DM.
Which class of constipation med to give to Gasteroperesis and DM?
Motility Stimulant
Motility Stimulant onset? Rx? Example?
Onset=6-48h
Rx needed.
Ex: Metoclopramide (dopamine antagonist)
What causes Opioid-Induced Constipation? What are the effects?
Opoids binding to Mu-receptors in GI tract. Decreases GI motility, decreases fluid absorption from gut, decreases intestinal secretion, and decreases defecation reflex.
What causes decreased GI motility, fluid absorption from gut, intestinal secretion, and defecation reflex.
Opoids binding to Mu-receptors in GI tract
What are first-line classes for Opioid-Induced Constipation? (Hint: 2)
Osmotic Laxatives, Stimulants
What class is second-line therapy for Opioid-Induced Constipation?
Mu-Opioid Receptor Antagonists
What are the two Mu opioid antagonists?
- Methylnaltrexone (Relistor)
2. Naloxegol (Movantik)
Naloxegol/Movantik MOA? Route? Caution with which fruit juice?
Mu-Opioid Receptor Antagonist in intestines. Oral! CYP 3A4- grapefruit juice.
MOA of Mu-Opioid Receptor Antagonists?
Inhibit peripheral Mu-Opioid Receptors without affecting analgesic Mu-Opioid actions. Does not cross BBB.
Methylnaltrexone (Relistor™) MOA, indication?
Mu-opioid receptor antagonist. Second-line when stimulants and osmotic laxatives fail.
Methylnaltrexone (Relistor™) route and onset?
SC. 4 hour onset.
Naloxegol (Movantik™) MOA, indication?
Mu-opioid receptor antagonist. Second-line(?) for OIC.
Naloxegol (Movantik™) route? Renal and liver concerns?
PO.
Renal dosing.
Grapefruit juice CYP3A4 interaction.
What second-line meds to use for someone on opiates and laxitives don’t work.
Mu opioid antagonists. Methylnaltrexone or Naloxegol
Chloride-Channel Activator MOA?
Stimulates Type 2 Chloride Channels in Small Intestine increasing Cl- rich secretions which stimulates intestinal motility.
“Waking up the bowel.”
Lubiprostone (Amitiza™) MOA? Onset?
Chloride-channel activator to stimulate intestinal motility.
24h onset.
Lubiprostone (Amitiza™) indications (hint:3)? Which is gender-specific?
- Women with IBS constipation.
- Chronic idiopathic constipation.
- Opioid-induced constipation.
Lubiprostone (Amitiza™) adverse-effect and due to what?
Nausea due to delayed emptying.
What does Ca++ supplementation, Oxycodone, and Seroquel to do pooping?
Causes constipation
If a PT has difficulty swallowing or is unable to drink fluids what two things to avoid?
- Metamucil
- Fiber
Causes a brick to form.
What to avoid with intestinal obstruction? What to use instead?
Avoid oral/PO. Use suppository or enema.
Two classes and specific meds to use when PT on opioids?
- Electrolyte Solution=PEG
2. Stool Softener=Docusate
Which category/med to avoid with electrolyte abnormalities? Which 3 to use instead?
Lyte abnormalities avoid Saline Cathartic (ex milk of mag). Use: 1. PEG/Miralax- Lyte Solution 2. Senna- stimulant 3. Colace- stool softener
What med/class used to prevent straining after surgery or MI?
Docusate (Colace™), a Stool Softener
PT w/cancer on methadone taking Docusate and Senna but still infrequent and hard stools. What are two possible meds to option switch her to?
Change to Methylnaltrexone or Naloxegol. (Mu-receptor antagonists.)
Saline Cathartic cause Lyte abnormalities (ex milk of mag). What three to use instead?
- PEG/Miralax- Lyte Solution
- Senna- stimulant
- Colace- stool softener