Constipation Flashcards
Causes of Constipation
- frequently caused by inadequate intake of dietary fiber
- also influenced by misconceptions about adequate frequency of stooling
- GI, metabolic/endocrine, pregnancy, neurogenic, psychogenic, drug-induced
Examples of GI Constipation
- IBS
- diverticulitis
- hernias
- volvulus
- stricture
- Hirshsprung’s dz
Examples of Metabolic/Endocrine Constipation
- hypothyroidism
- pheochromocytoma
- hypercalcemia
Pregnancy Induced Constipation
-secondary to depressed gut motility, inadequate diet and water intake
Examples of Neurogenic Constipation
- CVAs
- CNA or spinal injury
- Parkinson’s
Examples of Psychogenic Constipation
- improper toilet training
- occupational (eg truck drivers)
Examples of Drug-Induced Constipation
- analgesics (opiates)
- anticholinergics
- iron supplements
- aluminum and calcium containing antacids
- also CCBs, diuretics, clonidine, phenothiazines, TCAs
3 Options for Therapeutic Management of Constipation
- dietary modification
- increase exercise and fluid intake
- drug therapy
Dietary Modification for Constipation
- fiber: undigestable vegetable material –> increases stool bulk, increases retention of stool water, increases rate of transit through the GI tract
- results in increasing frequency of stooling
Dietary Sources of Fiber
-beans, whole grains, fruits, veggies, bran cereals
Fiber Products for Constipation
psyllium (Metamucil, Perdiem)
methylcellulose (Citrucel)
polycarbophil (Mitrolan)
Bulk-Forming Drugs MOA
- nondigested plant cell wall absorbs water into feces
- softens stool
Bulk-Forming Drugs Generics
- psyllium
- methylcellulose
- polycarbophil
Bulk-Forming Drugs Trade Names of:
- psyllium
- methylcellulose
- polycarbophil
- psyllium: (Metamucil, Perdiem)
- methylcellulose: (Citrucel)
- polycarbophil: (Mitrolan)
Bulk-Forming Drugs Efficacy
-best option for prevention of chronic constipation
Bulk-Forming Drugs Safety/AEs
- well tolerated
- flatulence, impaction possible
Emollients MOA
- stool softeners
- facilitate mixing of aqueous and fatty materials
Emollients Generics
- docusate sodium
- docusate potassium
Emollients Trade Names of:
- docusate sodium
- docusate potassium
- docusate sodium: Colace
- docusate potassium: Kaopectate
Emollients Efficacy
more effective for prevention of constipation
Emollients Safety/AEs
- very safe
- diarrhea or abdominal cramps possible
Disaccharides MOA
- metabolized to low molecular weight acids
- increase peristalsis
- osmotic agent
Disaccharides Generics
- sorbitol
- lactulose
Lactulose Trade Name
-cephulac
Disaccharides Efficacy
- very effective for chronic constipation
- may also be used to decrease serum ammonia
Disaccharides Safety/AEs
- expensive
- flatulence, belching
- cramps
- N/V/D
Glycerin MOA
lubricant and osmotic effect
Glycerin Trade Name
- Fleet
- Babylax
Glycerin Efficacy
- mild action
- ideal for children and infants
Glycerin Safety
very safe
Lubricants MOA
- coats stool and allows easier passage
- decreases absorption of water
- lubricant
Lubricant Generics
-mineral oil
Lubricant Trade Names
- agoral
- kondremul
Lubricant Efficacy
-effective for impaction and temporary relief
Lubricant Safety
- may decrease absorption of fat soluble vitamins with prolonged use
- risk of aspiration if given at bedtime
What is the purpose of treating a hepatic encephalopathy patient with lactulose?
-purposely inducing diarrhea to decrease serum ammonia levels and reverse the encephalopathy sxs
Diphenylmethane Derivatives MOA
-stimulation of gut motility
Diphenylmethane Derivatives Generic
Bisdacodyl PO
Bisacodyl Trade Name
Dulcolax
Bisacodyl Dose
10 mg PO x1 (also PR)
Diphenylmethane Derivatives Efficacy
-very effective for tx of acute constipation, prevention of opioid-induced constipation
Diphenylmethane Derivatives AEs
abd cramping possible
Anthraquinone Derivatives MOA
stimulant
Anthraquinone Derivatives Generics
- senna
- casantranol
Anthraquinone Derivatives Efficacy
- senna moderately effective
- casanthranol also in combo with docusate
Anthraquinone Derivatives AEs
abd cramping possible
Polyethylene Glycol MOA
osmotic
Polyethylene Glycol Trade Name
Miralax
Polyethylene Glycol AEs/Safetu
- appears better tolerated than other laxatives
- more costly
PEG Solution Trade Name
- Go-Lytely
- CoLyte
PEG Solution Efficacy
effective for whole bowel irrigation and prep for surgery
PEG Solution Safety
- reserve for refractory constipation
- requires 4L oral administration over 3 hours
Saline Cathartics MOA
- osmotic retention of fluid in intestine
- also increases peristalsis
Saline Cathartics Generics
- magnesium hydroxide
- magnesium citrate
Saline Cathartics Trade Name (for magnesium hydroxide)
Milk of Magnesia
Saline Cathartics Efficacy
reserve for bowel evacuation
Saline Cathartics Safety
- may result in electrolyte disturbances
- abdominal cramping and HTN possible
How long for bulk-forming drugs to take effect?
1-3 days
How long for emollient drugs to take effect?
1-3 days
How long for diphenylmethane derivative drugs to take effect?
6-12 hours
How long for disaccharide drugs to take effect?
1-3 days
How long for polyethylene glycol to take effect?
1-6 hours
How long for glycerin drugs to take effect?
1-3 days
How long for anthraquinone derivative drugs to take effect?
6-12 hours
How long for saline cathartic drugs to take effect?
1-6 hours
How long for lubricant drugs to take effect?
1-3 days
