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LAXATIVES, PART 1 | ||
DRUG NAME | magnesium hydroxide (Milk of Magnesia), magnesium citrate (Citrate of magnesia, Citroma), sodium phosphate (Fleet enema), lactulose (Duphalac, Constulose, Enuloc), polyethylene glycol (MiraLAX) | methylcellulose (Citrucel), polycarbophil (Equalactin, Konsyl Fiber), psyllium (Metamucil, Fiberall) |
CLASS | Osmotic laxatives | Bulk-forming agents |
MECHANISM OF ACTION | Draw water into the lumen to increase intestinal peristalsis | Draw water in the stool, forming a soft, bulky mass, which stimulates intestinal peristalsis |
INDICATIONS | Constipation | |
ROUTE(S) OF ADMINISTRATION |
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SIDE EFFECTS |
Lactulose
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CONTRAINDICATIONS AND CAUTIONS |
For saline laxatives:
For lactulose:
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LAXATIVES, PART 2 | ||
DRUG NAME | bisacodyl (Dulcolax), senna (Sennakot, ExLax) | docusate (Colace) |
CLASS | Stimulant laxatives | Emollient laxatives (stool softeners) |
MECHANISM OF ACTION | Irritate nerve endings in the intestinal walls, thereby stimulating smooth muscle contraction and intestinal peristalsis | Act as surfactant that allows the water to penetrate the stool and make it softer |
INDICATIONS | Constipation | Prevent constipation |
ROUTE(S) OF ADMINISTRATION |
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SIDE EFFECTS |
Senna
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CONTRAINDICATIONS AND CAUTIONS |
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NURSING CONSIDERATIONS: LAXATIVES | |||||
ASSESSMENT AND MONITORING | All laxatives
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CLIENT EDUCATION | All laxatives
Osmotic laxatives
Bulk-forming agents
Stimulant laxatives
Emollient laxatives (stool softeners)
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Laxatives are a group of medications that help the passage of stool, and are used to relieve constipation. Now, based on their mechanism of action, laxatives can be broadly divided into four main groups: osmotic laxatives, stimulant laxatives, bulk-forming agents, and emollients or stool softeners.
Most of these medications are taken orally, but some of them can also be given rectally in the form of enemas or suppositories, to cleanse the bowels before procedures like colonoscopies or surgeries.
Starting with osmotic laxatives, these include saline laxatives, such as magnesium hydroxide, magnesium citrate, and sodium phosphate salts; and indigestible sugars and alcohols, like lactulose and polyethylene glycol.
Both saline laxatives and indigestible sugars and alcohols are not well absorbed or digested, so they draw more water out of the intestinal cells and into the lumen via osmosis.
This increases intestinal motility, called peristalsis, which pushes the stool through the gastrointestinal tract and also helps mix the stool with water.
Moving on to bulk-forming agents, these include methylcellulose, polycarbophil, and psyllium. Now, these medications can’t be digested by the enzymes in our gastrointestinal tract, so they remain in the intestinal lumen and end up getting incorporated into the stool.
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