Ex. 6 - Constipation (66-67) Flashcards
How do you define constipation
Usually involved both decreased frequency plus signs and symptoms (>25% of the time)
-Cramping
-Bloating
-Lumpy/hard dry stools
-Straining
-Sensation of incomplete evacuation or blockage
Constipation stats
Over 4M in US are frequently constipated
At least 2.5 M/yr see their MD for constipation
More common in women, non-white and elderly
Most patients treat themselves
$500m to $800m yearly spent on tx
30-50% of elderly frequently use laxatives
-Higher in LTCF
Disorder of colonic motility or anorectal function
ABCs of defectaion
Muscles of mechanical barrier
Puborectalis
EAS
IAS
-Normally, the muscles tend to relax, go normally
Dyssynergic defecation
-Neurologic system plays a role
GI transit time
Mouth to anus time: Normally 30-40 hrs
Can be up to 72 hrs
-Anything speeds up: watery stools
Anything slows down: hard, dry stools - constipation
Food move too slowly through GI tract
Movement of water in and out of stool
-Slow transit results in more time for colon to absorb water from waste
-Resulting in stool, becoming hard and difficult to push out
Acute constpation
A noticeable change in normal bowel movement pattern
-Less than 3 bowel movements/week
Other key features
-Stools dry and hard
-BMs is painful and stools difficult to pass
-Feeling that bowels have not been fully emptied
Usually brought on by change in condition or drug
Chronic constipation
Primary causes
-Normal transit “Functional” symptomatic - (most common)
Slow transit
Evacuation disorder
Secondary causes
-Medications
-Obstruction (cancer, stricture)
-Metabolize (e.g. hypothyroid, hyprecalcemia)
-Neurological (eg. parkisnonism, MS)
Systemic (eg. sclerdoerma, amyloidosis)
-Psychiatric (depression, eating disorders)
Chronic constipation criteria
-Straining
-Lumpy or hard stools
-Sensation of incomplete evacuation
-Sensation of anorectal obstruction/blockage
-Manual maneuvers to facilitate defecations
-<3 defecations per week
Chronic constipation cont.
Symptoms lasting>6 weeks
-May respond to laxative tx but returns when laxatives d/c
-Does not respond to dietary changes alone
Chronic Idiopathic Constipation
-No identified cause
Constipation: Common causes
Especially if elderly
Dietary
-poor fluid intake
-decreased calorie intake
Failure to heed defecation reflex
Impaired physical mobility
Lack of privacy (LTCF)
Increased psychological distress
Disease states that slow down GI motility
-Diabetes
-Parkinson’s
-CNS injury or disease
-MS
Common drug causes of constipation
Analgesics/Opioids
-Mu receptor agonist in GI tract
Leading cause
Analgesics/NSAIDS
-NSAIDs to a much less extent than opioids
-Inhibition of PGs
-Prostaglandin E series play a significant role in GI physiology
-intestinal motility
-intestinal fluid movement
Antacids
-Aluminum, Calcium
Agents w/strong anticholinergic properties
-Antihistamines, antimuscarinics, amitriptyline
-Verapamil, Clonidine, Ca channel blockers
-Iron preparations
-Diuretics
-Chronic use of stimulant laxatives ???
-unlikely if normal doses are utilized
When to refer
Refer pt to PCP if:
-Symptoms have persisted (with appropriate interventions) for greater than two weeks w/o significant relief
-Who has black or tarry stools
-who has marked abd pain or discomfort
-who has a fever
-Also has severe nausea/vomiting
-Has a family history of IBD or colon cancer
-has drastic change in severity or nature of symptoms
Questions to ask patients complaining of constipation
How long have you been constipated? Why?
How often do you normally have a bowel movement?
-Why?
What is the size and color of your stools
-Why?
-Black stools indicate blood!!
Have you noticed periods of constipation mixed w/diarrhea?
-why?
Have you noticed a change in the caliber of the stool?
-Why?
Do you have much gas?
Why?
-gas shows GI tract is working
Has your appetite or weight changed?
-Why
What have you tried so far?
-Why
Bristol stool scale
Slow Transit
Type 1:
-Separate, hard lumps like nuts
Type 2:
-Sausage-like but lumpy
Type 3:
Like a sausage but with cracks in the surface
Type 4:
Like a sausage or snake, smooth and soft
Type 5:
Soft blobs with clear cut edges
Type 6:
Fluffy pieces with ragged edges, a mushy stool
Type 7: Watery no solid pieces
Fast transit
Measures to help promote regular bowel habits: water
Include ample fluids and fiber in diet
-6-8 glasses of water per day
Measures to help promote regular bowel habits: High fiber
Add high fiber foods to diet slowly
-20-30 g of fiber per day
-increase fiber over 7-10 days
-Minimize gas
-Natural fiber is degraded by bacteria
-Vegetables, fruits, beans, whole grains
Measures to help promote regular bowel habits: Prunes
Dried plums
-High concentration of simple sugars
-sorbitol
1 cup = 12 g of fiber
Dihydrophensylatin (natural laxative)
Alternative to prunes:
kiwis - 2 per day
Dried pitted prunes - 12 per day
Powder psyllium - 12 g per day
gas
19% with psyllium
18% with prunes
0% with kiwifruit
Measures to help promote regular bowel habits: lifestyle habits
-Do not ignore the urge to defecate
-Establish a regular, unhurried time for bowel movements
-encourage patients to defecate when colonic activity is greatest
-First thing inv AM
-30 mins after meals
Bulk laxatives
Examples:
-Psylium - Metamucil
Methylcellulose - Citrucel
-Calcium polycarbophil - Fibercon
MOA
-Forms emollient gels which retain water, swells, and stimulates BM
Bulk Laxatives: advantages and disadvantages
Advantages
-Soften stools better than docusate
-Well tolerated; few SE
Disadvantages
-Taste
-must have adequate fluid intake
-Gas formation
-Impact on drug absorption
-not ideal for bedridden patients
Bulk Laxatives: Special
Mix Citrucel with at least 8 oz Cold water - juice
Drink immediately
Produce less gas
Surfactnat/Emollient
Docusate (DOSS)
-100mg once or twice daily
MOA
-Decreases fecal surface tension
Stool softener
Advantages
-Safe
-Helps prevent hard stools (hemorrhoids)
Disadvantages
??? Efficacy
NOT effective for active constipation
Lubricant
Mineral oil
-30-60ml once daily
MOA
-Lubricates lumen of colon
Advantages
-Lubricates, softens
Disadvantages
-Poor patient acceptance; oily
-Only effective in prevention of constipation
-May decrease absorption of fat-soluble vitamins
Saline laxatives
Examples
-MOM; Mg citrate
MOA
-Draws fluid into colon which stimulates motility
Advantages
-Used for acute management of constipation; quick onset
-Most economical
Disadvantages
-Taste +/-
Avoid in renal pts (na, mg)
Fleet’s saline enema
-Rapid onset
Hyperosmotic agents
Examples
-Sorbitol: 30-60ml daily
-Lactulose: 30-60ml daily
-PEG: 17g in H2O daily
MOA
-Draws fluid into colon due to high concentration of sugar, PEG or glycerin
Hyperosmotic agents: Advantages and disadvantages
Adv:
-Well tolerated
-Softens while stimulating BM
-Excellent for chronic constipation
Disadv:
-1-3 day onset at usual doses
-Sweet taste of some agents
-Minor nausea, cramping
Hyperosmotic Agents examples
Glycerin suppositories
-Adult
-Children
Quick onset
PEG 3350: Miralax
-17g PO once daily
-Mix with 4-8oz liquid
-Onset in 1-3
-Well tolerated
Does not start working until in small intestine - do not take with antacids
Stimulant Laxatives
Senna 2 tabs 1-2* daily
Bisacodyl 1-2 tabs daily
-enteric coated
MOA
-Locally stimulates enteric nerves which stimulates contractions and mobility; also increases fluid and Na secretion into the lumen
Stimulant lax Advantages and Disadvantages
Advantages
-6-12 hours onset
-Works in pts with motility disorders
-DOC for OIC
Disadvantages
-Risk of nausea and cramping
-Avoid long term continuous use in patients with normal GI motility
Stimulant laxatives ex
Bisacodyl Suppositories
-10mg PR
-Quick onset
Newer Laxatives
Lubiprostone (Amitza
-MOA: activates Cl- channels
Notes: 24mcg BID with food + water Nausea; diarrhea; HA
$$$
Linaclotide (Linzess):
MOA: Increases Cl- and bicarbonate secretions
Notes: 145 mcg once daily 30min before first meal
$$$
Diarrhea is common
Plecanatide (Motegrity)
-MOA: Increases Cl- and bicarbonate secretions
Notes: 3mg once daily
Administer any time
$$$
Diarrhea is common
Lactitol (Pizensy)
MOA - Osmotic
Notes: 20g once daily
-Do not administer w/other meds
Acute Constipation
Relief:
ASAP - within 1 hour:
Enema*
Bisacodyl or Glycerin Suppository
-Rapid relief - Fleets
Relief 3-6hrs
Citrate of Magnesia
Larger doses of PEG
-Also used for GI preps
Relief within 24hrs:
Bisacodyl or Senna Tablets
Within 48hrs
Milk of Magnesia
PEG (Miralax)
Chronic Constipation
Step Therapy
One
-Relieve acute constipation
-Dietary modifications
Two
-Bulk forming laxatives + fluids
-Titrate dose
Three
-PEG (Miralax)
-Lactulose
-Sorbitol
Four
Short term use of stimulant, then maintenance agent
Five
-Lubiprostone
-Linalclotide
-Prucalopride
-Plecanatide
-$$$
-Usually reserved for chronic idiopathic constipation
Follow-up and assessment
1-2 days for acute constipation
1-2 weeks for chronic
-Stool frequency
-Episodes of diarrhea
-Dietary changes
-Any SE from meds
IESA
Is the drug Indicated?
Is the drug Effective?
Is the drug Safe?
Is the drug Convenient/Adherence?
Pharmacologic tx for special populations: Spinal cord injury pts and pregnancy, Diabetes
Spinal cord injury:
-Routine use of bowel stimulants
-Usually suppositories
Pregnancy:
-Diet, fiber, docusate
-Senna in more severe cases
Diabetics (neuropathy)
-Prokinetic agents
Metoclopramide
Prucalopride
-Stimulants
Pharmacologic tx for special populations: Opioids
Patients on opioids (OIC):
-Stimulants
-Then add docusate, lactulose, or PEG prn
Avoid bulk laxatives
Opioid receptor antagonists:
-When other tx does not work
Methylnaltrexone (Relistor)
-Mu opioid receptor antagonist
-Dosed based on wright
-8-12 mg SC every other day
-Except BM within 30 minutes
$$$
Naloxegol Movantik
-Mu opioid receptor antagonist
-25mg PO once daily; 12.5mg if CrCl <60ml/min
1 hr prior to 1st meal or 2hrs after meal
-Empty stomach
-High-fat meal increased extent and rate of absorption
-Tablet can be crushed
-$$$
GI procedure prep
Hyperosmotics or saline laxatives
Clear liquid diet starts day prior to procedure
-Jello; broth; popsicles; Gatorade; clear juices; coffee
-prep starts in afternoon/evening prior to procedure
Drinking large quantities of fluids is key
Oral prep agents
PEG
-Nulytely, Golytely, Halflytely, Colyte
-Frequently used as bowel
2-4L
8oz q10min
Refrigerate
SAS Prep:
Prior day to procedure
-Enjoy clear liquids all day
Oral prep agents cont.
Other commercial preps are used infrequently d/t risk of complications
use great caution in pts with
-Heart failure; renal disease; electrolyte abnormalities
-OsmoPrep, Viscol
-Suprep
-Suclear
-Prepopik
