Chapter 26

Laxatives and Antidiarrheals

Constipation p596• Condition in which passage of feces through

the lower GI tract is slow or nonexistent. This results in a reduction in frequency and an increase in difficulty of fecal evacuation.

Causes of constipation p596• Ignoring the urge to defecate• Environmental changes• Ingestion of low residue diet• Immobility• Emotional stress• Ingestion of constipating foods (dairy)• Use of constipating drugs: opiates,

anticholinergics, calcium or aluminum antacids• Chronic misuse of laxatives• Decreased fluid intake

Laxatives p596• Facilitate elimination of feces• Most laxatives are used to prevent or treat

constipation• Laxatives are also used to prepare pt for lower

GI studies or surgery

Stimulant Laxatives Table 26-1 p597• Action: chemical irritation of intestinal mucosa

–Examples: bisacodyl, senna• For short term use• Contraindicated: pt with abdominal pain, N&V,

rectal fissures• Most likely to cause laxative dependence

Saline Laxatives Table 26-2 p598• Draw water through the intestinal wall to increase

fluidity of stool and stimulate peristalsis– Result:

• Bowel distention • increased peristalsis • evacuation of stool

• Unpleasant taste• Systemically absorbed

Saline Laxatives p598-599• Result in:

– Poor client compliance– Risk for dehydration

• Examples: • magnesium citrate, • magnesium hydroxide (MOM), • magnesium sulfate (epsom salts)

• Contraindicated in pt with renal failure

Bulk-Forming Laxatives Table 26-3 p600• Safest laxative form

– Absorbs water to increase bulk – Distends bowel to initiate reflex bowel activity– Natural or semisynthetic

• Examples: – psyllium hydrophilic muciloid (Metamucil) – methylcellulose (Citrucel) – polycarbophil (Fibercon)

Bulk-Forming Laxatives cont

• Must be followed with a large amount of fluid to prevent GI obstruction

• Effects might not be evident for up to 3 days

Lubricant Laxatives p599

• Oils lubricate the fecal material and intestinal walls, thereby promoting fecal passage:– Prevent absorption of

fat soluble vitamins

• Example – Mineral oil (liquid

petroleum)• Not digested or

absorbed

Stool Softeners p600 • Fecal wetting agents

– Mix fats and fluids with the fecal mass– Stool becomes softer– Takes several days to work

• Example: docusate salts (Colace and Surfak)

• Not used to treat existing constipation• Useful to decrease strain of defecation in

cardiac patients

Suppositories p601 • Available containing stimulant drugs

– Glycerin• Absorbs water from tissues, creating more mass

– Bisacodyl • Induces peristaltic contraction by direct stimulation of

sensory nerves

Lactulose p601• Lactulose:

– hyperosmotic laxative– causes water to be drawn into the colon– Useful in treating hepatic encephalopathy

GoLYTELY p602 • Polyethylene glycol

– Bowel prep prior to procedures– Acts within one hour

• Produces a diarrheal state

Enemas p602• Solution contain salts (Fleet enema)

• Administered rectally and cause a laxative effect by osmotically drawing fluid into the colon to initiate defecation

• Pt in left side lying position, enema bad hung 12-18 inches above anus, lubricate 4-5 inches of catheter tip

Chronic Laxative Use • Long-term use of laxatives often results in

decreased bowel tone and may lead to laxative dependency

• Encourage– A healthy, high-fiber diet– Increased fluid intake– Mobility– Laxative use of no longer than 1 week

Diarrhea p602• Abnormally frequent passage of watery stools• Symptom of an underlying disorder• Treatment: reduce GI motility

Antidiarrheals that reduce GI motility Table 26-5 p603

• Example: – Paregoric

• Decreases peristalsis• Depresses the CNS• Decreases transit time through the bowel;

more time for water and electrolytes to be absorbed

.

Antidiarrheals that reduce GI motility cont p603

• Loperarmide HCl (Imodium)– Made from chemicals

related to meperidine, a narcotic

• Diphenoxylate HCl and atropine sulfate (Lomotil)– Narcotic and

anticholinergic drug

Nursing Implications• Monitor for therapeutic effect of laxatives or

antidiarrheals• Pt taking laxatives should be instructed to

increase fluid intake to avoid dehydration• Laxatives or enemas should not be used to

treat acute abdominal pain