meds for constipation and anorectal disorders

what are some examples of medications that can induce constipation

opioids

iron

aluminum antacids

Ca

anticholinergics

5-HT3 antagonists

calcium channel blockers

chemo

antidiarrheal abuse

bulk forming laxatives ex

psyllium (Metamucil)

polycarbophil (fiber con)

methylcellulose (citrucel)

wheat dextrin (benefiber)

Indications for bulk forming laxatives

relief of occasional constipation

fiber supplement

MOA of bulk forming laxatives

natural fiber- causes water retention, inc in fecal mass and stimulates peristalsis

pts who would benefit from using bulk forming laxatives

pts on low fiber diets

older adult pts

pts with Gi disorders

patients who should not strain

pregnant and post partum women

contraindications of bulk forming laxatives

fecal impaction, recent bowel surgery

gi obstruction or strictures

patients to be cautious with using bulk forming laxatives

diabetes or limited caloric intake

fluid restrictions

difficulty swallowing

intestinal stenosis, adhesions or ulcerations

ADE of bulk forming laxatives

farting

cramping in abdomen

choking if not taken with fluids

acute bronchospasm

drug interactions with bulk forming laxatives

can cause dec absorption of oral meds

separate dose from ALL OTHER MEDS by 2 hrs

dosing bulk forming laxatives

OTC

consume with at least 8 oz of fluid

delayed response- 12-24 hrs, could be 72 hrs

osmotic laxatives ex

polyethylene glycol (miralax)

glycerin

lactulose

sorbitol

saline laxatives fit in here

mag citrate

mag hydroxide

mag sulfate

sodium phosphate

indications for osmotic laxatives

occasional constipation relief

which osmotic laxative can be used in patients with renal failure or heart failure

miralax

which osmotic laxative is ok to use in all age groups

glycerin

which osmotic laxative is used for prevention and treatment of hepatic encephalopathy and how

lactulose

reduces blood ammonia concentrations

MOA of osmotic laxatives

draws water into bowel→ softens fecal mass→ stimulate bowel movement

contraindications of miralax

do not use in pts with bowel obstructions

ADE of osmotic laxatives

farting, cramping, bloating, high doses may cause diarrhea

Ade of glycerin

osmotic laxative

chronic use may reduce potassium levels!

dosing of osmotic laxatives

oral, powders, rectal suppositories, enema

PRN typically

which osmotic laxative works the fastest

glycerin suppository, 15-30 min

saline laxatives ex

mag citrate

mag hydroxide

mag sulfate

sodium phosphate

indications for saline laxatives

NOT FOR LONG TERM USE

acute constipation- mag citrate or phosphate

opioid induced- mag citrate

occasional consitpation relief- mag hydroxide

fecal impaction- rectal phosphate

which saline laxative can treat fecal impaction?

rectal phosphate products

MOA of saline laxatives

attracts and holds water in intestinal lumen (osmotic )

difference btwn osmotic and saline laxatives

saline falls under the category of osmotic, but also has electrolytes

warnings for saline laxatives

NO RECTAL under 2 years

NO ORAL under 5 years

avoid sodium products with renal or heart failure

NOT FOR LONG TERM USE

ADE of saline laxatives

bloating, cramping diarrhea

excess magnesium can have CNS depression effect!

sodium phosphate- low Ca

can cause electrolyte imbalances, vomiting, dehydration

drug interactions with saline laxatives

magnesium interacts with iron and tetracyclines

sodium phosphate interacts with sucralfate, diuretics, and ACE1s

saline laxatives dosing

oral or rectal

oral act in 30min to 3 hrs

rectal act in 2-15 min

stimulant laxatives ex

senna

bisacodyl (dulcolax)

indications for stimulant laxatives

chronic constipation due to opioids

bowel prep for colonoscopy

relief of occasional constipation

MOA of stimulant laxatives

increase secretion of water and electrolytes into the bowel

irritates sensory nerve endings in intestinal wall→ inc motility

stimulates peristalsis

warnings with stimulant laxatives

use cautiously in kids, limit use to less than 1 week

avoid in undx rectal bleeding, appendicitis, intestinal obstruction

ADE of stimulant laxatives

severe cramping

electrolyte and fluid deficiency

Senna- prolonged use results in melanotic pigmentation of bowel! and discolors urine

interactions with stimulant laxatives

biscodyl and any acid suppressor → avoid erosion of enteric coating

dosing of stimulant laxatives

oral

bisacodyl- suppository

lubricant laxatives ex

mineral oil

indications for lubricant laxatives

maintain soft stool

fecal impaction relief

LAST RESORT

lubricant laxatives MOA

keeps water in colon and lubricates intestines

ADE of lubricant laxatives

leakage of oil→ anal itching w large doses

lipid pneumonia- aspiration of oil

diarrhea, n/v, cramps

do not use in kids under 6 or in anyone that may have swallowing prob

LAST RESORT

drug interactions w lubricant laxatives

impairs absorption of ADEK, anticoagulants, OCP, digoxin

docusate emollients

dosing of lubricant laxatives

take WITHOUT FOOD

OTC, oral, rectal

rectal- 5-15 minutes

emollients ex

docusate sodium (colace)

docusate calcium

docusate/Senna

indications for emollients

PREVENTATIVE

used to prevent straining and painful defecation

post partum, severe cardiovascular dz, colostomies, recent abdominal sx

used with Senna for opioid induced constipation

MOA of emollients

anionic surfactants, act in small and large intestines to increase wetting efficiency of intestinal fluid

facilitate mix of aqueous and fatty substances to soften fecal mass

dosing emollients

otc

oral, liquid

may take up to 3-5 days to work

contraindications for emollients

do not use under 6 years

avoid in undetermined cause of abdominal pain and hx of intestinal obstruction

ADE of emollients

cramping, diarrhea

opioid receptor antagonists (peripherally acting)

methylnaltrexone (relistor)

alvimopan

naloxegeol

naldemedine

which opioid receptor antagonists are indicated for opioid induced constipation and which for post op

methylnaltrexone (relistor) - OIC

alvimopan - PO

naloxegeol - OIC

naldemedine - OIC

which opioid receptor antagonists may induce opioid withdrawal symptoms and which ones do not

methylnaltrexone (relistor) - withdrawal

alvimopan - NO withdrawals

naloxegeol - withdrawal

naldemedine -withdrawal

which opioid receptor antagonist do u have to enroll in a REMs program for

alvimopan

which opioid receptor antagonists do you not use in known or suspect gi obstruction

all except alvimopan

contraindications with alvimopan

do not use in pts getting opioids for over 7 days in a row

drug interactions with alvimopan

opioid agonists if received for more than 7 days in a row prior to alvimopan tx

intestinal secretagogues ex

lubiprostone (amitiza)

linaclotide (linzess)

plecanatide (trulance)

tenapanor (ibsrela)

which intestinal secretagogues are used for CIC and which are not

lubiprostone (amitiza)- CIC, IBS-C

linaclotide (linzess)- CIC, IBS-C

plecanatide (trulance)- CIC, IBS-C

tenapanor (ibsrela) -IBS-C only

which intestinal secretagogues are used for opioid induced constipation?

lubiprostone (amitiza)- OIC

linaclotide (linzess)- OIC

plecanatide (trulance)- OIC

tenapanor (ibsrela)- no

which medications can be used for hemorrhoid therapy

astringents - witch hazel, zinc oxide

local anesthetics -benzocaine, lidocaine, tetracaine

vasoconstrictors- epi, phenylephrine

corticosteroids - hydrocortisone ointment

astringents for hemorrhoid tx MOA

decrease irritation, itching and burning

DO NOT DEC PAIN

external use

local anesthetics for hemorrhoid tx MOA

blocks nerve conduction→ relieves burning and itching

comes in creams, sprays, pads, suppositories

vasoconstrictors for hemorrhoid tx MOA

constrict blood vessels by stimulating alpha receptors

can reduce swelling, itching, pain

creams, suppositories

corticosteroids for hemorrhoid tx MOA

anti inflammatory and vasoconstrictive to reduce itching and swelling

prolonged use can weaken tissue!

long term use at high concentrations can lead to systemic effects wh

what meds can be used to tx OIC

polyethylene glycol

senna

methylnaltrexone

nalxegol

lubiprostone