laxatives Flashcards
METHYLCELLULOSE
- Bulk forming laxatives (fiber)
- Mech of action = ingest fiber that you can’t digest and absorb to add bulk and retain water
–> NEED TO DRINK LOTS OF WATER
- TX of: constipation, minimize straining
- Adverse effects: GAS/BLOATING
GLYCERIN
- Surfactant (stool softener)
- Mech of action: coates and penetrates fecal material allowing it to slide out easier.
- TX for: consipation, minimize straining
- ADVERSE EFFECTS = nutrient malabsorption
LACTULOSE
- Osmotic agent
- Mech of action: induce changes in osmotic pressure with non-absorbable sugars and salts (oral or rectal admin)
- TX for: constipation, minimize straining, prior to surgical and endoscopic procedures
- Adverse effects: Gas, electrolyte flux
SENNA
- Stimulant
- Mech of action: stimulation of ENS inducing peristaltic contractions (oral or rectal admin)
- TX for: constipation, minimize straining, prior to surgical and endocsopic procedures
- ADVERSE EFFECTS = GI irritation
Tegaserod
- 5-HT4 receptor PARTIAL AGONIST
–> PROMOTES NT release in ENS resulting in motility
–> DECREASES firing of extrensic sensory neuron to the CNS (BLOCKS PAIN)
- TX for: chronic idiopathic constipation
- ADVERSE EFFECTS = GI and CV –> not availabe for general use
LUBIPROSTONE
- Chloride channel activator (CIC-2) (PROSTAGLANDIN DERIVATIVE)
–> increase luminal conc of chloride in the gut RESULTING in accumulation of sodium and water –> stool will soften and motility will be stimulated
- TX for: chonic constipation
- ADVERSE EFFECTS: nausea/vomiting and diarrhea
Methylnaltrexone
-Mu-opiod receptor antagonist (doesn’t penetrate CNS)
–> mu-opioid receptor delays intestinal motility (Constipation)
–> blocking the receptor will prevent constipation post op
- TX for: opioid-induced constipation during palliative care
- ADVERSE EFFECTS: abdominal pain, flatulence, nausea, diarrhea
Alvimopan
- Mu-opioid receptor antagonist
–> mu-opioid receptor delays intestinal motility (constipation)
–> blocking the receptor will prevent constipation post op
- TX for: postoperative ileus in hospitalized patients with bowel resection
- ADVERSE EFFECTS: abdominal pain, flatulence,nausea, diarrhea
–>MI effects (ONLY SHORT TERM USE)
Lpoeramide
- Opioid agonists
–> decrease peristaltic contractions
–> increase segmental (mixing) contractions
–> increased internal anal sphincter tone
–> decrease perception of GI distension
- TX for: Diarrhea (IBS)
- Adverse effects = constipation (VERY SAFE)
Diphenoxylate
- Opioid agonists
–> decrease peristaltic contractions
–> increase segmental (mixing) contractions
–> increased internal anal sphincter tone
–> decrease perception of GI distension
- TX for: diarrhea
- ADVERSE EFFECTS: CNS effects, atropine effects
Bismuth subsalicylate
- antidiarrheal agent
–> salicylate inhibits prostaglandin synthesis (in contrast to what may be occuring in the stomach)
–> bismuth compounds absorb bacterial toxins
- USE: non-specific diarrhea and travelers diarrhea
ADVERSE EFFECT = salicylate toxicity
Cholestryamine
- bile salt binding resins
–> reduce the increased osmotic pressure in the lumen of the large intestine caused by unabsorbed bile salts
- TX FOR: impaired bile-salt absorption mediated diarrhea (crohns diseases)
- adverse effects = bloating, flatus, consipation, fecal impaction, impaired fat absorption
Octreotide
- Somatostatin receptor agonist
–> activation of somatostatin receptor i GI tract INCREASES FLUID ABSORPTION and DECREASES MOTILITY
- TX for: secretory diarrhea
- SIDE EFFECTS –> decreased GI motility (nausea and pain)
–> not used regularly
