Question | Answer |
What are properties of lubricants? | Mineral oil (Haley's MO)
Coats fecal contents for easier passage
Reduces water reabsorption in colon - makes stool a little bit softer
Used to prevent straining
Decrease absorption of fat soluble vitamins (A, D, E and K) because of the coating |
What are properties of osmotic laxatives? | Milk of magnesia
Osmotic effect increases pressure in the bowels - draws water into intestinal lumen
Stimulates peristalsis
used for acute emptying of bowel
Avoid in patients with kidney dysfunction |
What are properties of stimulant laxatives? | bisacodyl (Dulcolax)
Irritate intestinal mucosa to increase motility - can cause semisolid stool in 6-12 hours
Used to prepare bowel for diagnostic procedures
Can cause severe cramping
People will abuse to lose weight
Chronic use fluid imbalance |
What are properties of surfactant laxatives? | Docusole sodium (Colace) - take 1-3 days to work
Detergents that lower surface tension
Increase secretion of water by intestine - causes bulk formation
Short-term therapy to prevent straining
Little to no value for chronic constipation |
What are properties of bulk-forming laxatives? | Psyllium (metamucil) - takes several days to work
Least irritating, most natural, identical to dietary fiber
Best for chronic constipation
Used to relieve mild, watery diarrhea
Can cause esophageal obstruction; turns to concrete upon standing |
What are the classifications of laxatives? | Lubricants
Osmotic
Stimulant
Surfactant
Bulk-forming |
What are indicators for laxative use? | Constipation - stool consistency; frequency
Treatment/procedure preparation (i.e. colonoscopy)
Eases defecation
Stimulates defecation |
What are some steps to take in bowel training? | Provide privacy and normal position
Recognize the "urge"
Gastro-colonic reflex - food in/ food out
Increase fluid intake - stimulates food in/food out reflex
Increase fiber
Increase activity
Avoid valsalva maneuver - very hard on heart |
How would one do an assessment for constipation? | Assess rectal and colon problems
Assess medications - narcotics cause constipation as does anasthesia
Assess lifestyle - eat enough fiber? active? stress? change in routine?
Assess age - older lose sensation, peristalsis and perineal/anal muscle tone |
What are the Rome II criteria for functional constipation? | Adults - Two or more of the following at 12 weeks: straining, lumpy hard stool, sensation of incomplete evacuation, less than 3 stools/week
Infants/children - pebble-like hard stool, firm stools 2X/week or less for 2 weeks |
What are properties of normal feces? | 75% H2O, 25% solid material
Soft, brown, formed stool
100-400 grams/day
Frequency varies with individuals |
What is the function of the large intestine? | 90% of H2O reabsorption occurs in the large intestine
Reabsorb H2O and electrolytes
Flatus and fecal elimination |
What are proton pump inhibitors? | Prilosec, Nexium (omeprazole)
Blocks the proton pump (H+)
Inhibits gastric acid secretion
Short half-life; supposed to be used for short-term
Side effects - headache, GI nausea, vomiting and diarrhea |
How do Histamine-2-antagonists work? | Same effects as antacids, but don't have to take as frequently
Inhibit histamine receptors of parietal cells (that produce acid)
Decrease acid production |
What are some Histamine-2-agonists? | End in -tidine
May have to double dosage to reach prescription strength
Cimetidine (Tagament) - interacts with multiple meds; increased confusion in older adults
Ranitidine (Zantac) - not as much confusion; doesn't enter CNS readily
Axid,Pepcid |
What are effects of antacids? | Increase pH; want above 5 to inhibit pepsin activity
Decreases destruction of gut wall
Neutralizes stomach acid |
What are properties of antacids? | Neutralize stomach acid
ADRs - constipation (aluminum hydroxide), diarrhea (magnesium hydroxide), drug interactions, too much sodium
Used for GERD and as calcium supplement |
What is some information on Helicobacter pylori? | Test for presence by biopsy, breath, serum and stool
Treatment - at least 2 antibiotics to minimize resistance
Also need to be on Histamine-2-antagonists or PPIs |
What are the classes of antiulcer drugs? | Antiobiotics - against H. pylori
Antacids
Antisecretory agents - Histamine-2-antagonist and proton pump inhibitors |
What are some lifestyle modifications to prevent peptic ulcers? | Stop smoking
Avoid ASA and NSAIDs
Little evidence to support changing diet, avoiding alcohol, or decreasing stress |
What are aggressive factors associated with peptic ulcer formation? | Helicobacter pylori - 75% of people with peptic ulcers have this bacterial infection
Gastric acid
Smoking - nicotine - decreases bicarbonate
NSAIDs
Corticosteroids |
What are defensive factors against the formation of peptic ulcers? | Protect the stomach
Mucus
Bicarbonate (neutralize acid)
Blood flow
Prostaglandins |