treatment of constipation and diarrhea

Question 1

dietary fiber and bulk-forming laxatives

Answer 1

psyllium husk, semisynthetic celluloses, and polycarbophils

Question 2

fiber and bulk-forming laxatives moa

Answer 2

increase delivery of water to the colon, increase bulk, and reduce pressure in the sigmoid colon resulting in more formed stools

Question 3

surfactant laxatives

Answer 3

docusates (anionic), poloxamers (non-anionic), castor oil (anionic and produces catharsis)

Question 4

castor oil adverse effects

Answer 4

colic, dehydration, and electrolyte imbalance in overdose

Question 5

stimulant laxatives moa

Answer 5

increase permeability of intestinal mucosa, increase back diffusion of water and electrolytes, increase propulsive contractility of the colon by stimulating the myenteric plexus, and stimulation of prostaglandin synthesis and increases intestinal secretion

Question 6

most potent class of laxatives

Answer 6

stimulant laxatives

Question 7

stimulant laxatives

Answer 7

diphenylmethanes (bisacodyl): pro-drug converted to active form by bacteria
anthraquinones: natural derivatives of lilliacease plants

Question 8

anthraquinones adverse effects

Answer 8

large doses can cause abdominal pain nephritis, melanotic pigmentation of colonic mucosa, and abnormal urine coloration

Question 9

magnesium laxatives moa

Answer 9

produce laxation by osmotic effect and through the release of cholecystokinin, which increases motility and secretion

Question 10

opiate mechanism of action

Answer 10

decrease salivary, gastric, and intestinal secretion, decrease stomach and intestinal motility, increase muscle tone, increase tone of intestinal sphincters, anti-spasmodic to decrease cramps

Question 11

opiates specifically formulated for diarrhea

Answer 11

paregoric (morphine in benzoic acid), diphenoxylate with atropine, loperamide (also inhibits calmodulin)

Question 12

anticholinergics for diarrhea

Answer 12

quaternary ammonium derivatives of atropine: propantheline and dicyclomine
anti-spasmodics to alleviate cramps

Question 13

infliximab moa

Answer 13

anti-TNF mAb for use in crohn’s disease; given with immunosuppressive therapy

Question 14

etanercept moa

Answer 14

fusion protein; binds TNF and prevents it from binding to its receptor

Question 15

adalimumab

Answer 15

humanized mAB to TNF alpha

Question 16

natalizumab

Answer 16

mAb to integrins to prevent immune cells from binding to intestinal cells for use in IBD

Question 17

sulfasalazine pharm

Answer 17

broken down by intestinal bacteria to ASA and sulfapyridine

Question 18

sulfasalazine adverse effects

Answer 18

anemia, rash, and impotence

Question 19

mesalalamine moa

Answer 19

5-ASA dimers; fewer side effects (i.e. less impotence) than sulfasalazine

Question 20

mercaptopurine moa

Answer 20

immune suppressant antimetabolite

Question 21

lactulose moa

Answer 21

semisynthetic disaccharide, metabolized by enteric bacteria to organic acids, causing acidification of the feces, slowing the nonionic diffusion on ammonia from colon to blood but converting the NH3 to ammonium, which is non-absorbable; laxative effect discharges the ammonium ions

Question 22

scopolamine moa

Answer 22

anticholinergic that blocks the cochlear sensation activation of muscarinic receptors by Ach; prophylaxis for motion sickness

Question 23

antihistamine drugs for use in motion sickness

Answer 23

older antihistamines have anti-cholinergic effects: dimenhydrinate, cyclizine, meclizine, and promethazine

Question 24

anti-dopaminergics for antiemesis moa

Answer 24

block dopamine receptors in the chemoreceptor trigger zone;

Question 25

anti-dopaminergics for antiemesis (drugs)

Answer 25

phenothiazines: chlorpromazine, prochlorperazine, and thiethylperazine
Butyrophenone derivatives: droperidol
benzamide derivatives: metoclopramide and trimethobenzamide

Question 26

serotonin antagonists for antiemesis moa

Answer 26

block 5-HT3 receptors in the stomach, small intestines and CTZ that are intimately involved in stimulating the VC to produce emesis; most effective anti emetics
co-administration with dexamethasone increases potency

Question 27

serotonin antagonists for antiemesis (drugs)

Answer 27

odansetron, granisetron, dolasetron, palonosetron

Question 28

aprepitant moa

Answer 28

substance P/neurokinin 1 receptor antagonist used as an adjunct drug for emesis prevention in chemotherapy; crosses the BBB

Question 29

benzodiazepine use in antiemesis

Answer 29

effective in patients with anticipatory vomiting because they cause somnolence and amnesia

Question 30

diphenylmethanes adverse effects

Answer 30

if OD - fluid and electrolyte loss and enterocyte damage

Question 31

castor oil moa

Answer 31

irritates mucosa to cause catharsis and is an anionic surfactant to soften stool

Question 32

lubiprostone moa

Answer 32

activates the CCL2 channel (via PKA mechanism) to increase intestinal secretion

Question 33

linaclotide moa

Answer 33

peptide agonist of guanylate cyclase that acts on intestinal cells to indirectly activate the CTFR channel

Question 34

bismuth moa

Answer 34

absorbs bacteria , viruses, and other toxins in the lumen of the gut; enhances mucus and HCO3 secretion, inhibits pepsin, and inhibits h. pylori

Question 35

most potent serotonin antagonist

Answer 35

granisetron

Question 36

serotonin antagonist with longest half life

Answer 36

dolesetron

Question 37

serotonin antagonist available IV

Answer 37

palonosetron

Question 38

corticosteroid antiemesis effects

Answer 38

used as adjunct therapy; increase antiemetic and decrease side effects by preventing prostaglandin production