constipation drugs Flashcards
magnesium onset of action
30 min-6hr
PEG, lactulose, sorbitol onset of action
24-48 hr
osmotic moa
draws water into intestinal lumen to soften stool in order to induce peristalsis
PEG AE
not absorbed and not metabolized by colonic bacteria so won’t have systemic AE,, maybe some cramping/gas
lactulose and sorbitol exposure systemic?
not absorbed but are metabolized by colonic bacteria
lactulose AE
bloating, cramping, nausea, diarrhea
when to caution lactulose
lactose intolerance
sorbitol AE
bloating, cramping, nause
avoid use of what with sorbitol
lamivudine (decreases conc of HIV med) and sodium or calcium polystyrene sulfonate (inc toxicity)
magnesium AE
DIARRHEA, hypermagnesemia (lethargy, hypotension, respiratory depression) leading to ileus & worsen constipation
avoid magnesium in ___
renal failure
magnesium drug interactions
HIV integrase inhibitors, tetracyclines, quinolones, levothyroxine, sodium/calcium polystyrene
bulking agents moa
water absorption into the intestines to soften stool which increases bulk to aid in peristalsis
rule with bulking agents
start low and go slow to prevent bloating and GI distress. eventual goal is 25-30 g fiber/day
bulking agent drug interactions
HIV integrase inhibitors, tetracyclines, quinolones, levothyroxine (take bulking agents 2 hours after or 6 hours before other agents)
bulking agents onset
12-72h
downside of soluble fiber
more AE: gas/bloating, abdominal distention. severe: esophageal or intestinal obstruction
bulking agents are _____ to manage acute constipation alone
not recommended (due to time of onset)
bulking agents contraindication
fecal impaction, GI obstruction
bulking agents administration warning
take with an adequate/large amount of water (8 oz). if not taken with enough water, can cause esophageal and intestinal tears
stool softeners
reduce surface tension of oil-water interface in the stool resulting in enhanced incorporation of water & fat leading to softened stools and easier defecation
stool softeners onset
24-72 hr
stool softeners AE
none
stool softeners drug interactions
inc. intestinal absorption of other agents when given concurrently, therefore dec. concentration
stimulant laxative moa
stimulate peristaltic activity via DIRECT ACTION on intestinal mucosa thereby promoting intestinal motility and increasing fluid secretion into the bowel. kinda like punching the gut
stimulant laxative warnings/usage
avoid long term use in older patients. not first line–must have adequate trial of fiber and osmotic laxatives first. often reserved for intermittent use
stimulant laxative onset
6-12 hr
senna ae
melanosis coli, abdominal pain, electrolyte abnormalities
bisacodyl ae
diarrhea & abdominal pain (decreases over time)
linaclotide moa
guanylate cyclase c agonist
linaclotide indication
chronic idiopathic constipation, IBS-C
linaclotide onset
5-7 days
linaclotide counseling
take on empty stomach 30 min before first meal
linaclotide AE
diarrhea, abdominal pain, flatulence
linaclotide contraindications
patients <18, mechanical GI obstruction
plecanatide moa
guanylate cyclase c agonist
plecanatide counseling
take po tablet without regards to food
plecanatide onset
24h
plecanatide ae
abdominal distension/tenderness, diarrhea, flatulence, nausea
plecanatide contraindications
patients <18, GI obstruction
plecanatide box warning
severe dehydration in pediatric patients
lubiprostone moa
type 2 chloride channel activator: moves water into intestinal lumen to improve intestinal transit and stool passage
lubiprostone indications
chronic idiopathic constipation, IBS-C (females), OIC (non cancer)
lubiprostone shows safety up to __
48 weeks
lubiprostone drug interaction
decreases effectiveness of methadone
lubiprostone onset
24 hours
lubiprostone counseling
take with food
lubiprostone ae
nausea, diarrhea, headache
lubiprostone contraindication
patients <18, GI obstruction
prucalopride moa
5HT-4 receptor agonist, promotes cholinergic and non-adrenergic neurotransmission to stimulate peristalsis
prucalopride indications
chronic idiopathic constipation
prucalopride counseling
take po tablet without regards to food
prucalopride dosing
adjustments CrCL<30 half dose, avoid in ESRD
prucalopride onset
24h
prucalopride AE
abdominal pain, nausea, diarrhea, headache
prucalopride contraindications
patients <18, GI obstruction, pregnancy/lactation
pamoras contraindication
intestinal instruction/malignancy
warning for pamoras
must stop all maintenance laxatives prior to initiation
methylnaltrexone indications
OIC with cancer (SQ), OIC non cancer (SQ or PO)
methylnaltrexone pearl
must be renally dose adjusted if CrCL<60
methylnaltrexone onset
30-60 min
methylnaltrexone ae
diarrhea, abdominal pain
alvimopan indication
short term treatment of post-operative ileus
alvimopan counseling
take po tablet without regards to food, avoid high fat meals
alvimopan rems
short term use only 15 doses due to increased risk for MI
alvimopan ae
hypokalemia
alvimopan contraindications
history of MI, use of opioids at therapeutic doses for >7 consecutive days
naloxegol indication
non cancer OIC
naloxegol dosing pearl
must be renally dosed if CrCL<60 or ESRD (half dose)
naloxegol counseling
swallow po tablet whole on empty stomach 1 hour before or 2 hours after first meal of the day
naloxegol ae
diarrhea, abdominal pain
naloxegol contraindiations
GI obstruction, use with strong CYP3A4 inhibitors like ketoconazole
naloxegol is a major substrate of __
CYP3A4 and p-gp
naldemedine indication
non cancer OIC
naldemedine counseling
take po tab w/o regards to food
naldemedine contraindications
GI obstruction
naldemedine is a major substrate of __
CYP3A4 and p-gpp\
