constipation and diarrhea

what is chronic idiopathic constipation?

• persists for several weeks

• cause is unknown

drugs that cause constipation

• antidiarrheals

• anticholinergics

  • antihistamines

  • antispasmodics

  • phenothiazines

  • TCAs

  • incontinence drugs

• cation-containing drugs

  • antacids: aluminum or calcium

  • iron

  • sucralfate

• colesevelam

• opioids

• select antihypertensives

  • clonidine

  • non-DHP CCB

medical conditions that can cause constipation

IBS

anal disorders (fissures, fistulae, rectal prolapse)

MS

cerebrovascular events

parkinson’s

pregnancy

spinal cord tumors

diabetes

hypothyroidism

IBS-C

idiopathic constipation with chronic/recurrent abdominal discomfort relieved by defecation

non-drug tx for constipation

• increasing fluid intake

• limit caffeine and alcohol intake

• increase physical activity

• replace refined foods with foods high in fiber

• use bathroom as soon as urge arises

when should a healthcare provider be consulted for constipation?

not improved after 7 days OTC tx

first line tx for constipation

bulk-forming drugs

dietary fiber

tx of choice for constipation in pregnancy

bulk-forming

dietary fiber

bulk-forming drugs MOA

absorb water in intestine — adds bulk to stool

osmotic drugs MOA

draw fluid into bowel lumen through osmosis

which OTC tx is recommended for constipation in most adults?

fiber

which OTC tx is recommended for iron-induced or hard stool constipation?

stool softener or bulk forming

which OTC tx is recommended for opioid-induced constipation?

stimulant or osmotic

which OTC tx is recommended for fast relief of constipation in adults?

bisacodyl or glycerin suppository

which OTC tx is recommended for fast relief of constipation in children?

glycerin suppository

bulk-forming drugs

• psyllium (Metamucil)

• calcium polycarbophil (FiberCon)

• methylcellulose (Citrucel)

• wheat dextrin (Benefiber)

psyllium

Metamucil

calcium polycarbophil

FiberCon

methylcellulose

Citrucel

wheat dextrin

Benefiber

ADRs of bulk-forming drugs

• flatulence

• abdominal cramping

• bloating

what else is required if bulk-forming drugs are used for constipation?

adequate fluids

osmotics

• magnesium hydroxide (Milk of Magnesia)

• magnesium citrate

• magnesium sulfate

• polyethylene glycol 3350 (MiraLax)

• glycerin (Fleet)

• lactulose (Constulose, Enulose)

• sodium phosphates (Fleet Enema)

• sorbitol

magnesium hydroxide

Milk of Magnesia

sodium phosphates

Fleet Enema

ADRs of osmotics

electrolyte imbalance

abdominal cramping

what else is lactulose used for?

hepatic encephalopathy

what osmotic do we need to use caution with renal impairment?

magnesium-containing

stimulants

• senna (Ex-Lax, Senokot)

• bisacodyl (Dulcolax)

bisacodyl

Dulcolax

ADRs of stimulants

abdominal cramping

when should stimulants be taken?

bedtime — BM will occur following morning

senna + docusate

Senna S

Senokot S

emollients (stool softeners)

docusate sodium (Colace)

when are emollients used for constipation?

when straining should be avoided

when stool is hard or dry

T/F docusate and mineral oil should be used together for opioid-induced constipation

FALSE — do NOT take together —> incr. absorption of mineral oil

lubiprostone (Amitiza) MOA

activates chloride channels in gut to increase fluid secretion and peristalsis

guanylate cyclase C agonists

linaclotide (Linzess)

plecanatide (Trulance)

lincaclotide

Linzess

guanylate cyclase C agonists (linaclotide) MOA

increase bicarb and chloride secretion into the lumen of the intestines

increase speed of GI transit and reduce abdominal pain

peripherally-acting mu-opioid receptor antagonists (PAMORAs)

alvimopan (Entereg)

methylnaltrexone (Relistor)

naloxegol (Movantik)

naldemedine (Symproic)

alvimoptan

Entereg

methylnaltrexone

Relistor

naloxegol

(Movantik)

naldemedine

Symproic

serotonin 5-HT4 receptor agonists

prucalopride (Motegrity)

prucalopride

Motegrity

lubiprostone (Amitiza) indications

• CIC

• IBS-C in adult females

• OIC

linaclotide (Linzess) indications

• CIC

• IBS-C

alvimopan (Entereg) indications

hospitalized surgery — decr. risk of post-op ileus

PAMORAs indications (except alvimopan)

OIC

prucalopride (Motegrity) indications

CIC

ADRs of lubiprostone

nausea — take with food and water

maximum ____ doses for alvimopan (Entereg)

15

CI to alvimopan (Entereg)

therapeutic doses of opioids for > 7 days immediately prior to use

BBW for alvimopan (Entereg)

risk of MI with long-term use

warnings for prucalopride (Motegrity)

suicidal ideation

who do we need to use extra caution in with laxatives for bowel prep?

CV disease

renal insufficiency

loop diuretic or NSAID use

laxatives used for bowel prep

• polyethylene glycol-electrolyte solution (CoLyte, GoLytely)

• sodium phosphates (OsmoPrep)

• sodium sulfate, potassium sulfate, and magnesium sulfate (Suprep Bowel Prep Kit)

BBW for sodium phosphates (OsmoPrep)

nephropathy

CI for sodium phosphates (OsmoPrep)

acute phosphate nephropathy

gastric bypass or stapling surgery

what cannot be consumed during bowel prep?

• solid or semi-solid foods

• red or blue/purple food coloring

• milk

• cream

• tomato, orange, or grapefruit juice

• alcohol

• cream soups

most cases of diarrhea are _____

a. bacterial

b. viral

b. viral

what is the most common cause of bacterial diarrhea?

E. coli

drugs that can cause diarrhea

• acetylcholinesterase inhibitors — donepezil

• antacids — magnesium

• abx

• antidiabetics

• antineoplastics

• colchicine

• drugs used for constipation

• misoprostol

• mycophenolate

• prokinetic drugs

• protease inhibitors

• quinidine

• roflumilast

non-drug tx for diarrhea

fluid and electrolyte replacement

-oral rehydration solutions (ORS)

non-infectious diarrhea sx relief short-term tx options

• bismuth subsalicylate (Pepto-Bismol)

• loperamide (Imodium)

MOA of loperamide (Imodium) and diphenoxylate/atropine (Lomotil)

antimotility drugs — slow intestinal motility, prolonging time for water absorption

pain and abdominal discomfort associated with IBS-D tx

antispasmodics — dicyclomine

bismuth subsalicylate (Pepto-Bismol) CI

• salicylate allergy

• taking other salicylates

• GI ulcer

• bleeding problems

• black/bloody stool

ADRs of bismuth subsalicylate (Pepto-Bismol)

• black tongue/stool

• salicylate toxicity — tinnitus

• nausea

loperamide (Imodium) dose

4 mg after first loose stool, then 2 mg after each subsequent

max 8 mg/day (self) or 16 mg/day (healthcare supervision)

loperamide (Imodium) BBW

torsades, cardiac arrest, sudden death with doses higher than recommended

do NOT use in children < 2 years old

CI to loperamide (Imodium)

acute dysentery (bloody diarrhea, high fever)

bacterial enterocolitis

how long can you use loperamide (Imodium) if self-treating?

≤ 48 hours

what antidiarrheal requires the use of blister packs or single-dose packaging?

loperamide (Imodium)

CI to diphenoxylate/atropine (Lomotil)

do not use if < 2 years old (liquid)

do not use if < 6 years old (tablets)

dicyclomine (Bentyl) warnings/ADRs

anticholinergic — caution in age ≥ 65 yo

caution in UC — toxic megacolon, paralytic ileus

CI to eluxadoline (Viberzi)

pts without gallbladder

mixed mu-opioid receptor agonist for diarrhea tx

eluxadoline (Viberzi)

abx for diarrhea (IBS without constipation)

rifaximin (Xifaxan)

serotonin 5-HT3 receptor antagonist for IBS-D

alosetron (Lotronex)