constipation Flashcards
constipation definition
decreased frequency plus:
cramping, bloating, lumpy/hard/dry stools, straining, sensation of incomplete evacuation
constipation etiology
over 4 million in US are frequently constipated
more common is: women, non-white, elderly
*most patients treat themselves
$500-800 mil./year
30-50% of elderly frequently use laxative (higher in LTCF)
disorder of colonic motility or anorectal function
acute constipation
less than 3 bowel movements/week
usually brought on by change in condition or drug
chronic constipation
symptoms lasting more than 6 weeks
may respond to laxative, but sxs return when d/c
does not respond to dietary changes alone
chronic idiopathic
common causes of constipation
elderly dietary - poor fluid intake, decreased caloric intake failure to heed defecation reflex impaired physical mobility lack of privacy (LTCF) increased psychological distress disease states that slow down GI motility* - DM, parkinsons, CNS and spinal cord injury or disease drugs
drugs that cause constipation
analgesics* - opioids (PO more than IV, can occur w/in 3 hours, mu receptor in GI tract) NSAIDs to a lesser extent (inhibition of PGs)
antacids (Al, Ca)
strong ACh properties (AHs, antimuscarinics, amitriptyline)
verapamil, clonidine, CCBs
iron
diuretics (remove fluid from system)
when to refer
sxs have persisted for greater than 2 weeks* w/o significant relief
black or tarry stools
marked abdominal pain or discomfort
fever
severe NV (obstruction)
FH of IBD or colon cancer
drastic change in severity or nature of symptoms
nonpharm treatment
include ample fluids and fiber in diet (6-8 glasses of water/day)
add high-fiber foods to diet slowly - 20-30 g/day, increase over 7-10 days (minimizes gas b/c natural fiber is degraded by bacteria), vegetables, fruits, beans, whole grains
prunes (dried plums) - high conc of simple sugars (sorbitol), 1 cup = 12 g fiber, dihydrophenylsatin (natural laxative)
power pudding - 1/2 C prune juice, 1/2 C applesauce, 1/2 C wheat bran flakes, 1/2 C whipped topping, 1/2 C prunes - blend, cover, refrigerate, take 1/4 C daily w breakfast
do not ignore urge to go
establish a regular, unhurried time for BMs (first thing in AM, 30 min after meals)
morning coffee?? craft beer???
SF gummy bears - sorbitol
routine physical activity
lexatives are generally for occasional* use only
bulk laxatives
psyllium (metamucil), methylcellulose (citrucel), calcium polycarophil (fibercon)
MOA: forms emollient gels which retain water, smells and stimulates BM, tension on GI wall creates peristalsis
advantages: softens stool beter than docusate, well tolerated, few SE
disadvantages: taste, must have adequate fluid intake, gas formation, impact on drug absorption*, not ideal for bed ridden patients
methylcellulose considerations: must mix with cold water, produces less gas
surfactant/emollient
docusate 100 mg QD or BID
MOA: decreases fecal surface tension, stool softener
advantages: safe, helps prevent hard stools
disadvantages: efficacy??, not effective for active constipation**
lubricant
mineral oil 30-60 ml QD
MOA: lubricates lumen of colon, “slide on through”
advantages: lubricates, softens
disadvantages: poor patient acceptance, oily, may decrease absorption of fat soluble vitamins
“magic mousse”
saline laxatives
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 patients (Na, Mg)***
fleets saline enema - rapid onset
hyperosmotic agents
sorbitol 30-60 ml QD, lactulose 30-60 ml QD, PEG 17 g in 4-8 oz H2O QD
MOA: draws fluid into colon due to high conc of sugar, PEG, or glycerin
advantages: well tolerates, softens while stimulating BM, excellent for chronic constipation
disadvantages: 1-3 day onset, sweet taste (lactulose), minor nausea, cramping
glycerin suppositories - child or adult, quick onset
karo corn syrup - used in children, 1 tsp in 6-8 oz formula
stimulant laxatives
senna 2 tabs 1-2x/day, bisacodyl 1-2 tabs QD, castor oil 30-60 ml
MOA: locally irritates nerves which stimulate mobility
advantages: 6-12 hours to onset, works in patients w motility disorders, DOC for patients on opioids**
disadvantages: cramping, avoid long-term use in patients with normal GI motility
bisacodyl suppository 10 mg PR, quick onset
chloride channel activator
lubiprostone (Amitiza)
activates chloride channels in small intestive resulting in increased intestinal fluid
chronic idiopathic constipation in adults
24 mcg BID with food*
diarrhea/nausea/HA
expensive
avoid in pregnancy*
reserved for patients who don’t tolerate other laxatives
guanylate cyclase-C receptor activator
linaclotide (Linzess)
increases chloride and bicarbonate secretions into the intestinal lumen; also inhibits sodium absorption
chronic idiopathic constipation in adults
145 mg QD 30 min before 1st meal of the day
expensive
treating acute constipation for patients seeking rapid symptomatic relief
0.5-3 hours: magnesium citrate, larger doses of PEG
0.5-1 hours: enemas (fleets, tap water, soap), suppositories (bisacodyl, glycerin)
6-24 hours: MOM, standard doses of PEG, bisacodyl, senna
follow up and assessment
1-2 days for acute constipation
1-2 weeks for chronic constipation
stool frequency, episodes of diarrhea, dietary changes, any SEs
step wise treatment of chronic constipation
1: be sure dietary interventions have been attempted (“power pudding”)
2: bulk forming laxative + adequate fluid intake
3: sorbitol/lactulose/PEG
4: short term stimulant laxative
5: lubiprostone, linaclotide
treatment of special populations w constipation
spinal cord injury: routine use of bowel stimulants (usually suppositories)
pregnant: diet, fiber, docusate, senna in severe cases
children: glycerin supp, karo syrup
diabetics: metoclopramide, stimulants
opioids: stimulants, then + docusate, lactulose, sorbitol or PEG PRN, avoid bulk laxatives*, “push not gush”
post op: start with MOM or PEG, then stimulants, push fluids
methylnaltrexone
useful for patients on opioids use when other treatment doesn't work dosed based on weight 8-12 mg SQ QOD expect BM within 30 min \$\$$
naloxegol
useful for patients on opioids mu opioid receptor antagonist 25 mg PO QD \$\$$ can be crushed take 1 hours before 1st meal or 2 hours after (empty stomach**)
alvimopan
indicated for tx of post-op ileus 12 mg PO 30 min before surgery 12 mg PO BID starting day after surgery max of 15 doses restricted access program \$\$$
preps for GI procedures
hyperosmotics or saline laxatives, clear liquid diet starts day prior to procedure, prep starts in afternoon prior to procedure
PEG - 2-4 L, 8 oz q 10 min, refrigerate, taste??? cyrstal light
osmoprep, visicol - Na phosphate, $$$
suprep - NaSO4, KSO4, MgSO4
suclear - NA sulfate, K sulfate, Mg sulfate, PEG 3350
prepopik - Na picosulfate, Mg hydroxide, anhyrous citric acid, lowest volume prep - 10 oz
avoid previous 4 with HF, renal disease, electrolyte abnormalities
