GI Agents: Diarrhea, Constipation, N/V, GERD Flashcards
Causes of constipation?
Low fiber diet, Low fluid intake, Inactivity, Aging, Diseases (IBS, DM, Hypothyroidism, MS, Parkinson’s, Anxiety, Depression, Cancer), Meds
Meds that can cause constipation?
Opioids, CCBs, Anticholinergics (TCAs, diphenhydramine, atypical antipsychotics), Paroxetine, Calcium supplements, Antacids w/ aluminum or calcium, Thiazides, NSAIDs
Goals of therapy for constipation?
-Increase frequency of BMs
-Titrate dose to soften stool
-Prevent recurrence
Non-pharmalogical tx for constipation?
-Hydration (8-12 glasses/day)
-Balanced diet (soluble fiber in food): apples, oranges, peas
-Exercise (walking, swimming)
-D/C meds that cause constipation
1st line treatment for constipation?
OTC laxatives
Targeted constipation therapy can be specific to which diagnoses?
Chronic idiopathic constipation, IBS-C, Opioid induced
Laxatives for constipation?
Stool softeners, Lubricants, Fiber/Bulk agents, Osmotics, Stimulants
Stool softeners for constipation?
Docusate sodium (Colace)
Libricants for constipation?
Mineral oil
Fiber/Bulk agents for constipation?
Psyllium (Metamucil), Methylcellulose (Citrucel)
Osmotics for constipation?
Glycerin, Lactulose, Sorbitol, Polyethylene glycol (PEG) (Miralax), Saline laxatives
Stimulants for constipation?
Bisacodyl (Dulcolax), Senna (Senokot)
MOA of Docusate?
Surfactant that lowers surface tension of stool (water penetrates, hydrates, and softens stool)
ROA of Docusate?
PO
Onset of Docusate?
1-3 days
Use for Docusate?
Avoid strain, preventative
Post-MI, surgery, hemorrhoids flare, combo w/ other meds for opioid induced
*doesn’t get bowels moving if already constipated
Precautions w/ using Docusate?
Efficacy is questionable (evidence low)
Special populations for Docusate use?
Popular w/ older adults, pregnancy, kids
Contraindications of Docusate?
Mineral oil (docusate inc. mineral oil absorption)
Mineral oil MOA?
Softens stool/lubricates lining of gut to facilitate defecation
ROA of Mineral oil?
PO
Onset of Mineral oil?
6-8 hrs
Use for Mineral oil?
Occasional constipation
Precautions with Mineral oil?
Avoid long-term use, bedridden pts (aspiration pneumonia), decreases absorption of fat-soluble vitamins
AVOID IN: kids, elderly, pregnacy
Contraindications of Mineral oil?
Docusate (increases absorption of mineral oil)
MOA of fiber/bulk agents for constipation?
Holds water in stool, adds bulk, promotes peristalsis
ROA for fiber/bulk agents?
PO
Onset of fiber/bulk agents?
1-3 days
Use of fiber/bulk agents?
Daily, dietary
Precautions w/ fiber/bulk agents?
Need a lot of fluids & movement (Do not use if bedridden/fluid limitations)
Side effects of fiber/bulk agents?
Bloating/cramps
Drug interactions w/ fiber/bulk agents?
Separate other meds by 1-2hrs
Special populations use of fiber/bulk agents?
Older adults must continue to drink & move around, pregnancy needs plenty of water, limited role for opioid induced
MOA of glycerin?
Local rectal stimulation: induces evacuation
ROA of glycerin?
Rectal suppository
Onset of glycerin?
quick action
Special populations use of glycerin?
Suppository sizes for kids/infants/adults, common use in children, can be used in pregnancy
MOA of lactulose, sorbitol (osmotic laxatives)?
Non-absorbable sugars that pull water into colon lumen & promote peristalsis
ROA of lactulose, sorbitol (osmotic laxatives)?
Oral, rectal
Onset of lactulose, sorbitol (osmotic laxatives)?
12hrs to 3 days
Use of lactulose, sorbitol (osmotic laxatives)?
Prevent & treat chronic constipation, daily use not recommended
Precautions with lactulose, sorbitol (osmotic laxatives)?
Electrolyte imbalance, DM (high amnt of lactose)
Frequency of osmotic laxatives?
Daily
MOA of Polyethylene glycol (Miralax) and PEG 3350 (GoLYTELY) (osmotic laxatives)?
Non-absorbable osmotic sugar that draws water into colon lumen but also contains electrolytes (prevents electrolyte shifts into colon)
ROA of Polyethylene glycol (Miralax) and PEG 3350 (GoLYTELY) (osmotic laxatives)?
PO
Use for Polyethylene glycol (Miralax) and PEG 3350 (GoLYTELY) (osmotic laxatives)?
Prevention/tx post MI, surgery, opioid induced (mix w water)
onset 1-3 days
Which laxative is used for colonic cleansing prior to diagnostics?
GoLYTELY (1 gallon jug) w/ watery evacuation in 1-6 hrs
Precautions w/ Polyethylene glycol (Miralax) and PEG 3350 (GoLYTELY) (osmotic laxatives)?
Cramping, diarrhea (but less than other laxatives)
Special populations use of Polyethylene glycol (Miralax) and PEG 3350 (GoLYTELY) (osmotic laxatives)?
Use in all ages, 1st line in hospitals for pregnancy
Saline laxatives?
Magnesium hydroxide (milk of mag), Magnesium citrate, Sodium phosphate
MOA of saline laxatives?
Non-absorbable salts that pull fluid into colon to promote peristalsis
ROA for saline laxatives?
PO
(sodium phosphate is also an enema)
Onset of MOM?
30 min - 8 hr
Onset of Mag. citrate?
30 min - 6 hr
Onset of PO Sodium phos.?
1-3 hr
Onset of Sodium phos. enema (Fleets enema)?
1-5 min
Use of saline laxatives?
Occasional use (every few weeks), avoid use on regular basis
Precautions w/ saline laxatives?
Cramps, dehydration, diarrhea, electrolyte imbalance
Special populations use of saline laxatives?
Caution dehydration, renal, cardiac
Stimulant laxatives?
Bisacodyl (Dulcolax) and Senna (Senokot)
MOA of stimulant laxatives?
Local mucosal irritation directly stimulates GI tract
Onset of stimulant laxatives?
PO: 6-12 hrs
Rectal: 15-60 min
Use of stimulant laxatives?
Tx and prevention: quick action
-can be used for opioid induced
Precautions w/ stimulant laxatives?
Cramping
Special populations use w/ stimulant laxatives?
Pts on chronic constipation meds, safe for older adults, no evidence that long-term use is harmful
Opioid induced constipation prevalence (cancer pts and non cancer pts w/ pain)?
Cancer pain 95%
Nonmalignant pain 80%
Which opioids can be constipating?
All
Does tolerance to opioid constipation develop?
Rarely
Laxatives for opioid induced constipation?
Senna, PEG
Pathophysiology of opioid induced constipation (OIC)?
Decrease Gi motility, increase absorption of fluid in gut, decrease intestinal excretions, decrease defecation reflex
(Result of u-opioid R’s in GI tract)
Target therapy recommendations by the AGA for OIC?
Recommended: Peripherally acting mu-opioid R antagonists (PAMORAs)
No recommendations: Intestinal secretagogues, Selective 5-HT agonists
Recommendations for PAMORAs?
Naldemedine (Symporic) PO: Strong rec.
Naloxegol (Movantik) PO: Strong rec.
Methylnatrexone (Relistor) PO or SubQ: conditional rec.
MOA for PAMORAs?
Block opioid from binding at mu R’s in GI tract –> inhibits delay in GI transit time, decreasing constipation effects of opioids
2nd line for OIC after laxatives fail?
PAMORAs
Administration of Naloxegol (Movantik)?
Empty stomach (1-2 hrs after first meal)
D/c all other laxatives (may re-initiate if suboptimal response after 3 days)
Onset of Naloxegol (Movantik)?
6-12 hrs up to 3 days
Avoid what food with Naloxegol (Movantik)?
Grapefruit (and juice)
Use of Naloxegol (Movantik)?
OIC in adults w/ noncancer pain
(off label for cancer pain OIC)
Caution w/ use of Naloxegol (Movantik)?
Severe abdominal pain, diarrhea (may result in hosp)
Dose adjustments for Naloxegol (Movantik)?
Renal dose adjustment
Avoid use in hepatic impairment
Metabolism of Naloxegol (Movantik)?
CYP3A4 (many d/d interactions)
Administration of Naldemedine (Symproic)?
w/ or w/o food
Onset of Naloxegol (Movantik)?
w/in 24 hrs