Week 3: GI Prokinetic, Anti-Emetics, Laxatives, Stool Softeners, Anti-Diarrheals

prokinetic drugs are a group that stimulates

motor function of gut

prokinetics for treating GERD

increase lower esophageal sphincter pressure

prokinetics for treating gastroparesis

improve gastric emptying

prokinetics for treating post-operative ileus

stimulate small intestine

prokinetics for treating constipation

accelerate colonic transit

neostigmine

acetylcholinesterase inhibitor

-enhances gastric, small intestine, colonic emptying

metoclopramide (reglan)

d2 receptor antagonist

-enhances gastric emptying, manages GERD and diabtetic gastroparesis

adverse effects of metoclopramide (Reglan)

CNS effects, drowsiness, restlessness, extrapyramidal effects

Diarrhea

frequent, loos, liquid bowel movements

-leads to poor food and nutrient absorption

diarrhea can cause

dehydration (too much water excreted, not enough absorbed)

diarrhea often results from

minor gi disorders or more serious conditions like inflammatory bowel disease (UC, chrons)

opioids cause

constipation, using their adverse effects to treat diarrhea, more sodium/water absorption

opioid derivatives can slow down

gi motility (binds to neuronal receptors on enteric nerve plexus)

side effects of opioid derivatives

nausea, constipation, abdominal discomfort

use of laxatives

infrequent/painful BM, after prolonged bed rest, SCI pts, as constipation treatment while using opioids, people who need to avoid straining, bowel prep before surgery

bulk forming laxatives

natural and semisynthetic dietary fiber that absorb water and swell, stretch bowel, and stimulate poop (peristalsis)

stimulant laxatives

unknown mechanism, may stimulate peristalsis by irritating intestinal wall and stimulate nerve plexus within gut wall

2 main examples of stimulant laxatives

bisacodyl (dulcolax) and senna (sennokot)

hyperosmotic laxatives

produces gradient that draws water into bowel/small intestine, increases fluid content and stimulates peristalsis

main hyperosmotic laxative

polyethylene glycol (MiraLax)

lubricants and stool softeners

facilitate entry of water into fecal mass, softens stool, easier to defecate

-may also exert laxative effect because stool increases in size which stimulates gi wall pressure

example of stool softener

docusate (colace)

adverse effects of all laxatives

nausea/vomiting, abdominal cramps, fluid/electrolyte abnormalities, laxative dependence

nausea and vomitting may be caused by

vestibular disorder, CNS dysfunction, pregnancy, sickness, med treatments (chemo, opioids, radiation)

seratonin receptor antagonists (5-HT3) as an anti-emetic

Ondansetron (Zofran), used to manage chemo induced nausea and vomitting

glucocorticoids as an anti-emetic

dexamethasone and methylpredinsolone, both have anti-emetic properties but unknown how

cannabinoids as an anti-emetic

dronabinol (marinol), antiemetic and appetite stimulant effect

h1 receptor antagonist as an anti-emetic

meclizine, used to prevent motion sickness and treat vertigo

anticholinergics as an anti-emetic

scopolamine, transdermal patch behind ear to treat motion sickness and decrease drooling

common CAMS for nausea/vomitting

ginger root, pre/probiotics

ginger root

used for nausea, vomitting, menstrual cramps, OA

-may be helpful with pregnancy (uncertain if benefits motion sickness,chemo, post anesthesia)

probiotics

live microorganizms that have health benefits (yogurt and fermented foods)

prebiotics

plant baed fibers that feed healthy bacteria in gut and probiotics (oats, bananas, leeks, garlic, spinach)

pre and probiotics used as an anti-ematic

prevent antibiotic associated diarrhea, treatment of infant colic, maintenance of remission of ulcerative colitis

kefir

probiotic, fermented milk drink with sour taste, made using culture of yeast/bacteria

stress ulceration is highly prevalent in patients with

burns, multitrauma, renal failure, cns trauma

rehab concerns for gi

many are inactive and suffer from adverse effects of bedrest (constipation and fecal impaction), those on chemo have nausea/vomittiing, most GI are safe adn do not produce bad adverse effects