ILE I U5 D2 Flashcards
Laxatives work by generally
increasing stool amount and/or changing consistency
How do saline, hyper osmotic, and chlorine channel laxatives work?
Creating osmotic gradient resulting in water being drawn into the lumen creating pressure and stimulating peristalsis
How do lubricant (mineral oil), and emollient agent laxatives work?
Soften fecal material and prevent colonic resorption of fecal water
How do stimulant laxatives work?
Stimulate motility of small and large intestine, and rectum
Bulk forming laxatives MoA
Increased fiber intake, increases stool volume and may make stools softer
Bulk forming laxatives (products)
Methylcellulose (caplets, powder to mix in water) Calcium Polycarbophil(caplets) Pysillium husk (capsules, powdered formulations to mix in water)
Bulk forming laxatives onset? Suitable for chronic use?
12-72 hours, suitable - just adding fiber. SYSTEMIC
Bulk forming laxatives ADRs
abdominal cramping, flatulence, some have high sugar content
Hyperosmotic agents MoA
Creates an osmotic gradient resulting in water being drawn into the lumen of the intestines and rectume, creating increased intraluminal pressure and stimulating peristalsis
Hyperosmotic laxative products
PEG (polyethylene glycol), glycerin suppositories
Hyperosmotic laxative duration?
12-72 hours (PEG) NON-SYSTEMIC, 15-30 min (suppositories)
Hyperosmotic laxative ADR
bloating, cramping, discomfort, diarrhea, dehydration,
Saline laxatives MoA
Create an osmotic gradient resulting in water being drawn into the lumen of the intestines and rectum, creating increased intraluminal pressure and stimulating peristalsis
Saline laxatives products
Magnesium Hydroxide (Milk of Magnesia)
Magnesium Sulfate (Epsom salts)
Magnesium Citrate
Sodium Phosphate salts –Enemas (Fleet® Enema)
Saline laxatives onset
oral; 30 min - 6 hours
enema; 2-15 min
Saline laxative ADR
Bloating, cramping, abdominal discomfort, and flatulence.•Diarrhea, dehydration, and related complications may occur, particularly with excessive use.•Elevated magnesium levels, particularly in patients with kidney failure, infants and children, and elderly
Emollient agent MoA
Anionic surfactants that increase wetting efficiency (promote mixing of aqueous and fatty substances) so that intestinal fluid mixes with fecal material to create a softer fecal mass. These are not true laxatives, but are recommended to prevent stool straining and prevent painful defecation.
Emollient agent products
Docusate Sodium (Colace® and others) –capsules and liquid•Docusate Calcium –capsules
Emollient agents onset
12-72 hours, up to 5 days
Emollient agents ADRs
diarrhea and mild cramping
Emollient agent interactions
Don’t use with mineral oil
Lubricant product MoA
Coats the stool and prevents reabsorption of fecal water. This results in a softer stool, that is more easily eliminated.
Lubricant products available
Mineral Oil oral liquid•Mineral Oil oral liquid emulsion•Mineral Oil liquid enema
Lubricant products onset
6-8 hours oral, 5-15 min enema
Lubricant product ADRs
Lipid Pneumonia –if aspirated•Leakage of Oil through anal sphincter•Absorption into intestinal mucosa, liver and spleen –foreign body reactions
Lubricant product interactions
Reduced absorption of drugs and fat soluble vitamins (A, D, E, and K)