Gi - Laxatives, Antacids, And Anti-Diarrheals

Front 1

Constipation

Back 1

Decrease in the frequency of bowel movements accompanied by difficult passage of hard, dry stools.

Front 2

Diarrhea

Back 2

Increase in the frequency of bowel movements accompanied by soft, watery stools. Can be acute or chronic.

Front 3

Psyllium

Back 3

Bulk-forming agent; used in the treatment of chronic constipation, chronic diarrhea, diarrhea with incontinence, and diarrhea with irritable bowel syndrome.

Hydrophilic colloids, prepared from the indigestible parts of fruits, vegetables, and seeds. In constipation, it forms gels within the large intestine, distending the intestine and stimulating peristalsis. In diarrhea, colloids absorb water giving more form to stool. Can also bind bile acids (bile-acid induced secretory diarrhea).

Front 4

Magnesium citrate

Back 4

Osmotic/saline/hyperosmotic; used in the treatment of constipation and chronic constipation, evacuation of colon prior to radiologic or endoscopic procedures, removal of ingested toxins (iron), and sugars (hepatic encephalopathy).

Non-absorbable/non-digestible salts or sugars hold water in the intestine by osmotic force. This distends the intestine and stimulates peristalsis.

Front 5

Magnesium hydroxide

Back 5

Osmotic/saline/hyperosmotic; used in the treatment of constipation and chronic constipation, evacuation of colon prior to radiologic or endoscopic procedures, removal of ingested toxins (iron), and sugars (hepatic encephalopathy).

Non-absorbable/non-digestible salts or sugars hold water in the intestine by osmotic force. This distends the intestine and stimulates peristalsis.

Front 6

Docusate

Back 6

Surfactant (stool softener); used in treatment of constipation and adjunct therapy for hemorrhoids.

Anionic surfactants become emulsified with stool, softening it and making passage easier. Docusate is also a weak contact laxative which increases NaCl secretion via cAMP, however, not as useful once constipation has already occurred.

Front 7

Mineral oil

Back 7

Lubricant; used to treat fecal impaction, post-MI/surgery/partum to avoid straining.

Penetrates and lubricates feces for easier passage; prevents water reabsorption. Some absorption when given orally; no absorption with edema.

Front 8

Bisacodyl

Back 8

Irritant/stimulant/contact; used to treat constipation and as preparation for surgery, delivery, or GI exam.

Contact irritants have effects on enterocytes, enteric neurons, and muscle. They cause accumulation of water and electrolytes and stimulate intestinal motility via several different pathways (prostaglandin/cAMP; NO/cGMP; inhibition of Na+, K+-ATPase).

Front 9

Cascara sagrada

Back 9

Irritant/stimulant/contact; used to treat constipation and as preparation for surgery, delivery, or GI exam.

Contact irritants have effects on enterocytes, enteric neurons, and muscle. They cause accumulation of water and electrolytes and stimulate intestinal motility via several different pathways (prostaglandin/cAMP; NO/cGMP; inhibition of Na+, K+-ATPase).

Front 10

Castor oil

Back 10

Irritant/stimulant/contact; used to treat constipation and as preparation for surgery, delivery, or GI exam.

Contact irritants have effects on enterocytes, enteric neurons, and muscle. They cause accumulation of water and electrolytes and stimulate intestinal motility via several different pathways (prostaglandin/cAMP; NO/cGMP; inhibition of Na+, K+-ATPase). Castor oil is hydrolyzed to ricinoleic acid which stimulates fluid and water secretion and speeds GI transit. The onset of action is prompt.

Castor oil can damage micro-villi and increase intestinal permeability. Cramping is prominent.

Front 11

Methylnaltexone

Back 11

Subcutaneous injection; used to treat opioid-induced constipation and post-operative ileus.

Peripheral mu opioid receptor antagonist; As a quaternary amine, it cannot cross the blood brain barrier - and does not affect CNS opioid receptors.

Front 12

Lubiprostone

Back 12

Oral capsules; used to treat chronic idiopathic constipation in adults; irritable bowel syndrome with constipation (females > 18); no restriction on length of use.

Agonist at gastrointestinal CLC-2 chloride channels. Activates channels in apical membrane of the intestine, which increases production of chloride rich intestinal fluids without affecting serum Na+ or K+ levels.

Front 13

Kaolin-pectin

Back 13

Bulk-forming agent; used to treat chronic diarrhea, diarrhea with incontinence, and diarrhea with irritable bowel syndrome.

Hydrophilic colloid that absorbs water and gives more form to the stool. Can also bind bile acids (bile-acid induced secretory diarrhea).

Kaolin-pectin is a nonspecific absorbent. There is no net loss of water or NaCl. It is also thought to bind bacterial toxins.

Front 14

Loperamide

Back 14

Narcotic analogue; used to treat acute, nonspecific diarrhea and chronic diarrhea.

Opiates stimulate opiate receptors in the myenteric plexus, mediating delayed intestinal transit and reduced secretion.

Front 15

Diphenoxylate

Back 15

Narcotic analogue; used to treat acute, nonspecific diarrhea.

Opiates stimulate opiate receptors in the myenteric plexus, mediating delayed intestinal transit and reduced secretion.

Front 16

Difenoxin

Back 16

Narcotic analogue; used to treat acute, nonspecific diarrhea.

Opiates stimulate opiate receptors in the myenteric plexus, mediating delayed intestinal transit and reduced secretion.

Front 17

Bismuth subsalicylate

Back 17

Used to treat diarrhea and traveller's diarrhea.

May bind bacterial toxins; also absorbs fluids in the gut. Anti-secretory effects if infectious diarrhea. Salicylate may have non-specific anti-inflammatory effects.

Front 18

Cholestyramine

Back 18

Bile acid binder; used to treat secretory diarrhea, post-operative diarrhea (hyperlipidemia/hypercholestrolemia unresponsive to diet).

Anion exchange resin that binds bile acids.

Front 19

Octreotide

Back 19

Anti-secretory agent; used to treat severe refractory secretory diarrhea (i.e. AIDS diarrhea, espcially cryptosporidium); endocrine tumor-related diarrhea (carcinoid, VIPoma).

Front 20

Sucralfate

Back 20

Topical mucosal protective agent; used in the treatment of duodenal and gastric ulcers (not useful in preventing or healing NSAID induced ulcers).

Forms an ulcer-adherent complex with proteinaceous exudate at the ulcer site and acts as a barrier to further damage by acid, pepsin, & bile salts. May also absorb bile salts. May stimulate mucosal prostaglandin and bicarbonate secretion; binds EGF and fibroblast growth factor to promote mucosal repair.

Front 21

Misoprostol

Back 21

Systemic; used in the prevention of NSAID-induced gastric ulcers or mucosal injury caused by NSAIDSs (induction of labor, incomplete and therapeutic abortions).

Antisecretory effects (inhibits gastric acid secretion) and mucosal protective properties. Unclear if its effects are due to antisecretory effects, mucosal protection, or both.

Front 22

Antacids

Back 22

Used for the relief of GI symptoms. Now used for symptom management only.

Antacids react wit HCl to form chlorides, water, and CO2. Components are mixed to balance side effects and prolong activity. Hydroxides of aluminum and magnesium are the most common components.