73. Constipation + Diarrhea Flashcards
Medical conditions that can cause constipation
IBS (constipation-predominant)
Anal disorders (fissures, fistulae, rectal prolapse)
Multiple sclerosis
CV events
Parkinson disease
Spinal cord tumors
DM
Hypothyroidism
When constipation persists for several weeks or longer, and cause is unknown, it is termed ____
chronic idiopathic constipation (CIC)
Idiopathic constipation a/w chronic or recurrent abdominal discomfort that is relieved by defecation is termed ____
IBS with constipation (IBS-C)
T/F: Non-drug treatments are preferred for constipation
True
What are non-drug treatments for constipation?
Increasing fluid intake (64oz daily recommended)
Limiting caffeine and alcohol intake (to avoid dehydration)
Increasing physical activity
Eating foods high in fiber is useful
Common side effects of drugs used for constipation
Diarrhea and abdominal cramping
What type of drug is first-line for constipation?
Bulk forming drugs (e.g. fiber like psyllium)
What type of drug is treatment of choice for constipation in pregnant pts?
Bulk forming drugs (e.g. fiber like psyllium)
How do osmotics work for constipation?
contain large ions or molecules that are poorly absorbed, draw fluid into bowel which distends the colon and increases peristalsis
Why are stimulants and stool softeners often given together in pts using opioids?
Opioids cause constipation
Stimulants = push
Stool softener like docusate = makes easier to push
Why are pts on iron supplements also on docusate?
Iron supplements make stool hard, docusate softens stool
How do lubricants like mineral oil work for constipation?
Coat bowel and stool with waterproof film, keeps moisture in the stool and makes pooping easier
Key drugs that are constipating
Antacids (aluminum, calcium containing)
Antidiarrheals
Clonidine
Colesevelam
Anticholinergic drugs: antihistamines (e.g. diphenhydramine), antispasmodics (e.g. baclofen), phenothiazines (e.g. prochlorperazine), TCAs (e.g. amitriptyline), incontinence drugs (e.g. oxybutynin)
Iron
Non-DHP CCBs (esp verapamil)
Opioids
Sucralfate (contains aluminum complex)
Which OTCs do you recommend for constipation in most adults?
Fiber
Which OTCs do you recommend for iron-induced/hard-stool constipation?
Stool softener (e.g. docusate) or bulk-forming drug
Which OTCs do you recommend for opioid-induced constipation?
Stimulant (e.g. senna, bisacodyl) or osmotic (e.g. PEG) laxative
Which OTCs do you recommend for constipation in pregnant pts?
Fiber
Which OTCs do you recommend for constipation in pts that need fast relief?
Adults: bisacodyl or glycerin (more gentle) suppository)
Children: glycerin suppository
Examples of bulk forming drugs used for constipation
Psyllium (Metamucil)
Calcium polycarbophil (FiberCon)
Methylcellulose (Citrucel)
Wheat dextrin (Benefiber)
Side effects of bulk forming drugs used for constipation
Flatulence, abd cramping, bloating
what is a counseling point for bulk forming drugs used for constipation?
adequate fluids are required
FiberCon has calcium, caution with binding drug interactions
Examples of osmotic drugs used for constipation
Magnesium hydroxide (Milk of Magnesia)
Polyethylene glycol 3350 (MiraLax)
Glycerin
Lactulose (Constulose, Enulose)
Sodium phosphates (Fleet Enema)
Side effects of osmotic drugs used for constipation
Electrolyte imbalance, abd cramping
What is a concern with use of magnesium hydroxide (Milk of Magnesia)?
Caution with renal impairment and do not use if severe renal impairment
Lactulose is commonly used for ____
hepatic encephalopathy
Examples of stimulant drugs used for constipation
Senna (Senokot, Ex-Lax)
Bisacodyl (Dulcolax)
When should oral stimulants used for constipation be taken?
Bedtime to induce bwoel movement int he morning
Emmolients (stool softeners) like docusate (Colace) is often preferred when straining should be avoided (e.g. ____)
postpartum, post-MI, anal fissures, hemorrhoids
How does lubiprostone (Amitiza) work for constipation?
Chloride channel activator, acts on chloride channels in gut, leading to increased fluid and peristalsis
How does linaclotide (Linzess) work for constipation?
Guanylate cyclase C agonist, increase chloride and bicarbonate secretion into the lumen of the intestines, increasing speed of GI transit and reducing abdominal pain
How does alvimopan (Entereg) work for constipation?
Peripherally-acting mu-opioid receptor antagonist (PAMORAs) act on mu-opioid receptors in the GI tract, decreasing constipation
Luubiprostone (Amitiza) indications
CIC, IBS-C, OIC
Linaclotide (Linzess), plecanatide (Trulance) indications
CIC, IBS-C
Alvimopan (Entereg) indications
Surgery - for hospitalized surgery pts to decrease risk of post-op ileus
Prucalopride indications
CIC
Methylnaltrexone (Relistor), Naloxegol (Movantik)
OIC
Side effects of lubiprostone (Amitiza)
Nausea
Others: diarrhea, abd pain, abd distension, HA
Side effects of linaclotide (Linzess)
Diarrhea, abd pain, flatulence
Contraindications of Alvimopan (Entereg)
Therapeutic dose of opioids for > 7 consecutive days immediately prior to use
Prucalopride (Motegrity) warnings
suicidal ideation
Although usually safe and well-tolerated, laxatives for colonoscopy can cause ____, especially oral sodium phosphates such as ___
fluid and electrolyte losses
OsmoPrep
Use extra caution in pts with ______ or taking _____ before starting laxatives used for whole bowel irrigation
CVD, renal insufficiency
Taking loop diuretics (d/t additional fluid loss) or NSAIDs
Boxed warning for OsmoPrep (sodium phosphates)
Nephropathy
Contraindication for OsmoPrep (sodium phosphates)
Acute phosphate nephropathy, gastric bypass, or stapling surgery
When are doses of bowel prep regimens typically given?
Evening before colonoscopy and morning of coloscopy
Before a colonoscopy, be on a clear liquid diet. Do NOT consume ___
sold or semi-solid floods, anything with red or blue/purple food coloring, milk, cream, tomato, orange or grapefruit juice, alcohol, cream soups
Brand name for polyethylene glycol-electrolyte solution (for bowel prep)
Colyte, GoLytely
Brand name for sodium phosphates (for bowel prep)
OsmoPrep
Brand name for sodium sulfate, potassium sulfate, and magnesium sulfate (for bowel prep)
Suprep Bowel Prep Kit
Drugs that can cause diarrhea
ACEi (e.g. donepezil)
Antacids containing magnesium
Abx (esp broad-spectrum), diarrhea may be infectious (e.g. C. diff)
Antidiabetics (e.g. metformin, GLP-1RA)
Antineoplastics (e.g. irinotecan, capecitabine, fluorouracil, methotrexate, TKIs)
Colchicine
Drugs used for constipation (e.g. laxatives)
Misoprostol
Mycophenolate
Prokinetic drugs (e.g. metoclopramide, cisapride)
Protease inhibitors (especially nelfinavir)
Quinidine
Roflumilast
T/F: Most cases of diarrhea are bacterial
False - viral
___ is the most common bacterial cause of diarrhea
E. coli
Recurrent idiopathic diarrhea a/w chronic or reoccurring abdominal discomfort that is relieve by defecation is termed ____
IBS with diarrhea (IBS-D)
Non-drug management of diarrhea includes ____
fluid and electrolyte replacement with oral rehydration solutions (ORS) such as Pedialyte, Enfamil Enfalyte, Gatorade
Most patients with non-infectious diarrhea who require symptomatic relief can use short-term ____ or ___ as needed
Bismuth subsalicylate (Pepto-Bismol) or Loperamide
___ and ___ are antimotility drugs that slow intestinal motility, prolonging time for water absorption
Loperamide and diphenoxylate
MOA eluxadoline (Viberzi)
Mixed mu-opioid receptor agonist (in contrast to PAMORAs which are antagonist)
Contraindications for bismuth subsalicylate (Pepto-Bismol)
Salicylate allergy, taking other salicylates (e.g. aspirin), GI ulcer, bleeding problems, black/bloody stool
Concern with use of Pepto-bismol with anticoagulants or antiplatelets or NSAIDs
increased risk of bleeding
Loperamide (Imodium A-D) Dosing
4mg PO after the first loose stool, then 2 mg after each subsequent loose stool
Max: 8mg/day (Self-care) or 16mg/day (healthcare supervision)
Contraindications for loperamide (Imodium A-D)
acute dysentery (bloody diarrhea + high fever)
Pseudomembranous colitis (C. diff), bacterial enterocolitis
Others: abd pain without diarrhea, acute ulcerative colitis
Boxed warnings for loperamide (Imodium A-D)
TdP, cardiac arrest and sudden death with higher doses than max dose (do NOT exceed)
Do not use in children < 2yo
Contraindications for Diphenoxylate/atropine (Lomotil)
Risk of respiratory and CNS depression in children
Do not use if <2 yo, or < 6yo for tablets)
Others: diarrhea caused by enterotoxin-producing bacteria or C.diff, obstructive jaundice
Liquid formulation of Diphenoxylate/atropine (Lomotil) is recommended in children ___
<13 yo
Anticholinergic effects of Lomotil come from the ___compontent
Atropine
Dicyclomine (Bentyl) warnings
Anticholinergic, caution in pts ≥ 65yo (Beer’s Criteria) and mild-moderate ulcerative colitis (can cause toxic megacolon or paralytic ileus)
Side effects of dicyclomine (Bentyl)
Dizziness, dry mouth, nausea, blurred vision, somnolence, weakness, nervousness
Contraindications of Eluxadoline (Viberzi)
Pts without a gallbladder
What are some oral medications for diarrhea that are used less commonly?
Antibiotics (Rifaximin) - for IBS without constipation; costly and relapse often occurs
Serotonin 5HT-3 receptor agonist (Alosetron) - approved for women only, but restricted use d/t risk of ischemic colitis