Laxatives Lecture PDF

Question 1

If colon fluid reabsorption is excessive, stool consistency will be ___, if insufficient, then ___

Answer 1

dehydrated and harder to pass (constipation), watery diarrhea

Question 2

Best source of fiber

Answer 2

Bran (about 40% fiber raw)

Question 3

Constipation 1 criteria that must exist to diagnose

Answer 3

feces being hard and dry (regardless of how often they are passed)

Question 4

Indications for laxative use (4)

Answer 4

• reduce painful elminiation associated with episiotomy, hemorrhoids and other anorectal lesions
• patients with CV disease to prevent straining
• compensate for loss of tone in abdominal and perineal muscle in geriatric patients
• empty bowel prior to procedure or those on narcotics

Question 5

Rapid acting laxatives definition and examples (2)

Answer 5

Act within 2-6 hours but impart watery consistency to stool, useful for diagnostic procedures or surgery

• saline laxatives
• polyethylene glycol

Question 6

Bulk forming agents mech of action

Answer 6

Effects identical to dietary fiber, form stool 1-3 days after treatment initiated, swell in water and form gel softening fecal mass and increasing bulk

Question 7

Bulk forming agents indications (3)

Answer 7

• temporary constipation
• IBS or diverticulosis
• symptomatic diarrhea relief

Question 8

Bulk forming agents ADR’s (1)

Answer 8

-administration with full glass of water to prevent esophageal obstruction

Question 9

Bulk forming agents examples (3)

Answer 9

• psyllium
• methylcellulose
• polycarbophil

Question 10

Surfactants mech of action

Answer 10

Produce soft stool after several days of treatment, alter consistency by lowering surface tension facilitating passage of water into feces

Question 11

Surfactant examples (1)

Answer 11

-docusate sodium/potassium/calcium

Question 12

Stimulant (irritant) laxatives mech of action

Answer 12

ACt on intestinal wall to produce net increase in amount of fluid and electrolytes within the intestinal lumen, promote accumulation by increasing secretion of water and ions into intestine and reducing water and electrolytes absorption, most act on colon within 6-12 hours

Question 13

Bisacodyl (dulcolax) drug class and function

Answer 13

Stimulant laxative, indicated for intermittent use to treat constipation or as bowel prep

Question 14

Senokot (x lax) drug class, mech of action, and ADR (1)

Answer 14

Anthraquinone derivative, thought to stimulate aurbach’s plexus, changes urine color

Question 15

Castor oil

Answer 15

Only stimulant laxative that acts on the small intestine, metabolized in the GI tract to active compound, acts within 2-6 hours to produce stool of watery consistency but is too powerful for routine management of constipation

Question 16

Osmotic laxatives mech of action

Answer 16

Poorly absorbed salts draw water into intestinal lumen increasing fecal mass stretching intestinal wall stimulating peristalsis

Question 17

Osmotic laxatives function, ADRs (3)

Answer 17

low dose produce semisoft stool in 6-12 hours, high dose in 2-6 hours for bowel prep

-Dehydration, renal dysfunction, heart failure

Question 18

Polyethylene glycol (miralax) function and ADR’s (3)

Answer 18

Osmotic laxative relatively safe for occasional constipation,

• N/V
• bloating
• flatulence

Question 19

Mineral oil drug class and function

Answer 19

Lubricant laxative given orally or rectally posesses greater potential adverse effects than docusate and thus routine use should be discouraged

Question 20

Laculose and sorbitol function

Answer 20

Saccharides used orally or rectally as having an osmotic effect allowing fluid to retain in colon, resulting in soft stool in 1-3 days, reserved as second line for patients who do not respond to bulk forming laxatives, can enhance intestinal excretion of ammonia (useful for portal hypertension)

Question 21

Immunomodulators for inflammatory bowel dz

Answer 21

2nd line agents being used earlier in treatment to induce remission and maintain

Question 22

TNF inhibitors 3 examples and funcion

Answer 22

-infliximab (remicade)
-adalimumab(humira)
certolizumab (cimizia)
Treatment for moderate to severe ulcerative colitis and crohns and RA

Question 23

TNF inhibitors ADR’s (2)

Answer 23

• increased risk of serious infection

- reactivation and dissemniation of Tb

Question 24

Tofacitinib (xeljanz) drug class and function and ADR’s (2)

Answer 24

Synthetic PO inhibitor of janus kinase, 1st PO agent approved for moderate to severe ulcerative colitis treatment
-TB and other opportunistic infections, bone marrow suppression

Question 25

dicyclomine drug class and function, ADR’s (3)

Answer 25

anti-spasmodic used to treat irritable bowel syndrome, dry mouth, urinary retention, blurry vision

Question 26

What antibiotic is preferred for travelers diarrhea in pregnant women?

Answer 26

Azithromycin

Question 27

Natalizumab (tysabri) function and ADR

Answer 27

Maintenance of moderate to sever crohn’s, ADR is progressive multifocal leukoencephalopathy (PML)