66: Constipation Flashcards
Constipation
-dec freq
-disorder of motility and rectal function
-cramping, bloating
-hard dry stools
-straining, blockage
Gi transit time
-mouth to anus
-30-40 hours
-upto 72 hours can still be normal tho
movement of water in and out of stool
-more time for colon to absorb water from waste
-results in stool becoming hard and difficult to push out
Acute constipation
-noticeable change in normal bowel movement pattern
-less than 3/week
-dry, hard stools
-painful movements
-hard to pass stool
-brought on by change in condition or drug
Chronic constipation
-more than 6 weeks
-may respond to lax but it comes back
-does not respond to diet
Common causes of chronic constipation
-dietary (poor fluid/calorie intake)
-failure to heed defecation reflex
-impaired physical mobility
-lack of privacy
-inc distress
Disease states that slow GI motility
-diabetes
-parkinsons
-CNS probs
-MS
-constipation
Common drug causes of constipation
-opioids
-NSAIDs
-Antacids
-strong anticholinergics
-iron
-vearpamil, clonidine, Ca channel blockers
-diuretics
-chronic use of stimulant lax
Refer constipated pt if
-symptoms >2weeks
-black/tarry stool
-ab bain or discomfort
-fever
-severe N/V
-family history of IBD or colon cancer
-drastic change in symptoms
Measures to promote bowel movements
-ample fluids and fiber (add slowly)
-6-8 glasses of water per day
-prunes, kiwi, psyllium
-do not ignore urge to defecate
-poop first thing in the AM and within 30 min after meals
Dietary fiber
-add slowly over 7-10days to minimize gas
-20-30g/day
-veggies, fruits, beans, whole grains
Prunes
-sorbitol
-12g fiber
-dihydrophenylsatin (natural lax)
Bulk lax products
-psyllium (Metamucil)
-Methylcellulose (citrucel)
-Calcium polycarbophil (Fibercon)
Bulk lax moa
-forms emmolient gels that retain water
-swells and stimulates BM
Bulk lax pros
-soften stool better than DOCUSATE
-few side effects
bulk lax disadvantages
-taste
-must drink enough fluids
-gas
-impact on drug absorption
-not ideal if beddridden
Bulk lax admin
-mix citrucel w at least 8 oz cold water
-drink immediately
-produce less gas
Surfactant / Emoillient product
-Docusate (DOSS) 100mg qd or bid
Docusate
-surfactant/emmolient lax
-100mg qd or bid
-helps prevent hard stools (hemorrhoids)
-NOT effective for active constipation
Lubricant product for constipation
-Mineral Oil
Mineral oil
-lubricant for constipation
-30-60mL qd
-lubricates lumen and softens stool
mineral oil disadvantages
-oily
-only effective in PREVENTION of constipation
-may dec absorption of fat-soluble vitamins
Saline laxative products
-MOM
-Mg Citrate
-Saline Enema (rapid onset)
Saline laxatives moa
-draws fluid into colon which inc motility
-quick onset (good for acute)
-most economical
avoid saline laxatives in
renal patients (Na Mg)
Hyperosmotic agents for constipation
-Sorbitol 30-60mL/qd
-Lactulose 30-60mL/gd
-PEG 17g in H2O qd
-Glycerin suppositories (quick onset)
Hyperosmotic agents MOA
-draws fluid into colon due to high concentration of sugar, PEG, or glycerin
-softens stool while stimulating BM
-great for chronic
Hyperosmotic agents cons
-1-3 day onset
-sweet taste
-minor nausea, cramping
PEG (miralax)
-hyperosmotic for constipation
-17g PO qd
-mix w 4-8oz liquid
-onset in 1-3 days
-well tolerates
Stimulant lax products
-Senna 2 tabs qd or bid
-bisacodyl (enteric coated) 1-2 tab qd
Stimulant lax MOA
-locally stimulates enteric nerves
=contraction and mobility
=inc fluid and Na secretion into lumen
Stimulant lax pros
-6-12 h onset
-works in pt w motility disorders
-DOC for OIC
stimulant lax cons
-risk of nausea and cramping
-avoid long-term use in pts w normal GI motility
Bisacodyl suppositories
-stimulant lax
-10mg PR
-quick onset
Newer lax
-Lubiprostone
-Linaclotide
-Plecanatide
-Lactitol
Lubiprostone
-24mcg BID wf + water
-activates chloride channels
-N/D, HA
-$$$
Linaclotide
-145mcg qd 30 min before first meal
-inc chloride and bicarbonate secretions
-diarrhea
-$$$
Plecanatide
-3mg qd
-inc chloride and bicarbonate secretions
-diarrhea
-$$$
Lactitol
-20g qd
-osmotic
-do NOT admin w other meds
Chloride channels
-allow water to pass into lumen
Options to relieve acute constipation within 1 hour
-Enema
-Bisacodyl or Glycerin suppository
-fleets is RAPID
Options to relieve acute constipation within 3-6 hours
-citrate of magnesia
-larger doses of PEG
-also used for GI prep
Options to relieve acute constipation within 24 hours
-bisacodyl or Senna tablets (stimulant)
Options to relieve acute constipation within 48 hours
-Milk of Magnesia
-PEG
-hyperosmotic
Chronic constipation step therapy
- relieve acute (dietary mods)
- Bulk lax and fluids
- PEG, lactulose or sorbitol
- Short-term stimulant then maintence agent
- Lubiprostone, linaclotide, prucalopride, plecanatide (CIO)
Follow up constipation
-1-2 days for acute
-1-2 weeks chronic
-stool freq
-episodes of diarrhea
-deitary changes
-any SE from meds
Tx of constipation in spinal cord injury
-routine use of bowel stimulants
-usually suppositories
Tx of constipation in pregnancy
-diet, fiber, docusate
-senna in more severe cases
Tx of constipation in diabetics
-prokinetic agents (metoclopramide, prucalopride)
-stimulants
Tx of constipation in pts on opioids
-stimulants
-then add docusate, lactulose, or PEG prn
-AVOID bulk lax
-opioid antagonists if those dont work
Opioid antagonists for constipation in pt on opioids
-Methylnaltrexone
-Naloxegol
Methylnaltrexone (Relistor)
-mu opioid antagonist
-dose based on weight
-8-12mg SC every other day
-BM within 30 min
-$$$
Naloxegol (Movantik)
-opioid receptor antagonist
-25mg PO qd, half if CrCl <60ml/min
-1 hr prior to 1st meal or 2 hrs after meal (empty tummy, high-fat meal increases rate and extent of aabsorption)
-tablet can be crushed
-$$$
Preps for GI procedures
-hyperosmotics
-saline lax
-clear liquid diet
-drink lots of fluids
-day before
Oral prep agents
-PEG
-SAS prep
-OsmoPrep, Visicol
-Suprep
-Suclear
-Prepopik
PEG for GI procedure prep
-Nulytely, Golytely, HalfLytely, Colyte
-2-4L
-8 oz q10min
-fridge
-add crystal lite for flava
SAS Prep
-day before procedure
-clear liquids all day
-1 bottle miralax into 2 bottles gatorade
-fridge
0drink extra 8 oz clear fluid every hour
-4 5mg bisacodyl at noon
-at 2pm drink miralax 8oz every 10-20min over 1 hour
-wait 30 min then drink second bottle at same rate
Other commercial prep agents
-not used bc risk of CVD, renal and electrolyte abnormalities
-osmoprep, suprep, suclear, prepopik
