NVDC Tx II Flashcards
what are time frames for acute, persistant and chronic diarrhea
acute 14 days
chronic >30 days
what viruses and bacteria cause acute diarrhea
norwalk, rotavirus
shigella, salmonella, campylobacter, staph, e coli
don’t forget protozoa
what drugs induce diarrhea
reserpine, sulfonamides, tetracylcines, broad spec antibiotics, cholinergic agonists, osmoitc and stimulant laxatives, prokinetic agents, PGs and quinidine
MOA loperamide
inhibit presynaptic cholinergic nerves in submucosal and myenteric plexuses, increase transit time, increase fecal water absorption, decrease mass colonic movements
why is loperamoid non prescription even though opiod
does not cross bbb
no analgesic properties
no potential for addiction
therapeutic use loperamide
mainstay nonspecific Tx diarrhea
adverse effects loperamide
toxic megacolon in those with active IBD
not used in patieints with ulcerative colitis or acute bacillary or amoebic dysentery
what is ocreotide and MOA
somatostatin analog
inhibits secretion of hormones and transmitters because it acts like somatostatin
therapeutic use ocreotide
those with advanced symotomatic tumors
diarrhea due to vagotomy or dumpign syndrome as well as diarrhea for short bowel syndrome or AIDS
used in small doses to stimulate motility
adverse effects ocreotide
inhibits pancreatic secretion
nausea, abdominal pain, flatulence, diarrhea
can cause gallstones
hyperglycemia, hypothyroidism, bradycardia
when do you not use anti diarrheals
bloody diarrhea, high fever, systemic toxicity
if diarrhea worsens with Tx
what is criteria for constipation
<3 bowel movement per week
what drugs can induce constipation
opiog analgesics, antichoinergics, antacids with Al or CaCo, Fe and NSAIDs
most important feature of Tx for constipation
dietary modification (increase fiber)
first line for constipation prevention
bulk forming laxatives and docusates
types of bulk forming laxatives
metamucil, citrucel, fiber con etc…
MOA bulk forming laxatives
indigestible, hydrophilic colloids which absorb water that forms a gel that distends colon and promotes peristalsis
adverse effects bulk formint laxatives
bloating and flatus
need to take in suffiecient fluid to avoid obstruction
what are the stool softeners
docusate oral or enema and glycerin suppository
MOA stool softener
allows water and lipids to prenetrate stool which softens it
therapeutic use stool softeners
to prevent constipatino and minimize straining (post operative patients)
what is used to prevent and treat fecal impaction
mineral oil
MOA osmotic liaxatives
soluble non absorbable, increase stool liquidity
therapeutic use of non-absorbable sugars or salts
Tx acute constipation
prevent chronic constipation
why is MgOH not used prolonged in patients with renal insufficiency
hyper Mg
adverse effects of sorbitol and lactulose
severe flatus and cramps
types of osmotic laxatives
Mgcitrate, MgOH, NaPO4,
polyethylene glycol
adverse effects NaPO4
cardiac arrhythmias from hpokalemia, hypernatremia, hypocalcemia, hyperphosphatemia
can lead to acute renal fialure from CaPO4 deposition
What is used for colon cleansing before procedure
polyethylene glycol
MOA polyethylene glycol
isotonic fluid, contains inert osmotically active sugar with Nasulfate, NaCl, NaHCO3, KCl
ingest 2-4 L over 2-4 hours
MOA stimulant laxatives
direct stimulation Enteric nervous system and colonic electrolyte and fluid secretion
therapeutic use stimulant laxatives
not 1st line
intermittend use from patients who do not respond to bulking and osmoitc agents
risks of long term use stimulant laxatives
dependence and destruction of mesenteric plexus resulting in colonic atony and dilation
what are the anthraquinone derivavties
aloe, senna, cascara
what are the diphenylmethane derivatives?
used for?
bisacodyl tab or suppository
used with PEG for colonic cleansing prior to colonscopy
What is used in patients with chronic constipation who fail to conventional 1st line therapy
chloride channel activator that stimulates Cl in small intestine increasing motility
MOA opiod R antagonists
inhibit opoid R
do not cross bbb
inhibits peripheral without analgesic effects
therapeutic use methylnaltrexone
opoid antagonist
approved for opiod induced constipation
subcut
contraindication methynaltrexone
GI obstruction
what is used short term to shorten period of post operative ileus
alvimopan
what is use of serotonin R agonist
increase GI motility and cardiac rate
enhance LES pressure and peristalsis, accelerates gastric emptying
What is linaclotide and MOA
guanylate cyclase C agonist
binds g cyclase on luminal surface intestine and increases cGMP which increase Cl and HCO3 secretion increasing intestinal fluid and dec GI transit time
what is used for chronic idiopathic constipation and IBS with constipation >18 y.o
linaclotide
diabetic gastroparesis is common finding in which DM
II
what prokinetic agents are available for GI
metoclopramide and serotoni agonists and erythromycin/macrolides
MOA metoclopramide
central and peripheral dopamine R antagonist, serotonin agonist, serotonin antagonists, cholinesterase inhibitor
metoclopramide does what
enhances motility of upper GI tract, accelerates gastric emptying, increases esophageal peristalsis, increases LES pressure
therapeutic use metoclopramide
prior to meals and at bedtime to control nausea and vomiting
adverse effects metoclopramide
cross bbb so extrapyramidal Sx: tardive dyskinesia
restlessness, drowsiness, insomnia, anxiety, agitation, depression
hyperprolactinemia can cause galactorrhea, breast tenderness and menstrual irregularities
What is adverse effect of serotonin agonists for prokinetic GI
fatal cardiac arryhthmias
MOA erythromcyin and macrolids for prokinetic GI
agonist at motilin T increased frequency and amplitude of antral contractions and initiats gastric phase III contractions
therapeutic use erythromycin
short term improvement gastric emptying in diabetic gastroparesis
long term limited by concerns about toxicity, pseudomembranous colitis and induction of resistant bacterial strains, development of tolerance
adverse effects of erythromycin
abdominal pain, cramping, nausea, diarrhea, vomiting
malabsorption
tolerance develops rapidly (motilin downregulation)
