Lower GI Pharmacology

Question 1

L2: Name two agents used exclusively in patients with IBS.

Answer 1

Alosetron and Tegaserod

Question 2

L2: Which pharmacologic agent(s)? Agonist at 5HT4 receptors to stimulate release of neurotransmitters involved in peristaltic reflex and motility

Answer 2

Tegaserod

Question 3

L2: Which pharmacologic agent(s)? Anti-diarrheal agent that may precipitate Reye’s Syndrome in pediatric patients

Answer 3

Bismuth salicylate

Question 4

L2: Which pharmacologic agent(s)? Anti-emetic agent with side effects of central sympathomimetic actions, behavioral disturbances, and abstinence syndrome upon discontinuation

Answer 4

Dronabinol

Question 5

L2: Which pharmacologic agent(s)? Anti-emetic that may cause extra-pyramidal symptoms

Answer 5

Dopamine Receptor Antagonists: Metoclopramide, Phenothiazines (prochlorperazine)

Question 6

L2: Which pharmacologic agent(s)? Anti-emetic that may cause QT prolongation

Answer 6

Serotonin Receptor Antagonists: Ondansetron

Question 7

L2: Which pharmacologic agent(s)? Antimuscarinic agent used for prevention and treatment of motion sickness (some efficacy in post-op emesis)

Answer 7

Scopolamine

Question 8

L2: Which pharmacologic agent(s)? Block 5-HT3 receptors at the chemoreceptor trigger zone in the CNS

Answer 8

Serotonin Receptor Antagonists: Ondansetron

Question 9

L2: Which pharmacologic agent(s)? Block 5HT-3 receptors on sensory and motor neurons to decrease pain and colonic motility

Answer 9

Alosetron

Question 10

L2: Which pharmacologic agent(s)? Block dopamine receptors in the chemoreceptor trigger zone

Answer 10

Dopamine Receptor Antagonists: Metoclopramide, Phenothiazines (prochlorperazine)

Question 11

L2: Which pharmacologic agent(s)? Blocks Substance P at neurokinin 1 receptor

Answer 11

Aprepitant

Question 12

L2: Which pharmacologic agent(s)? Effective in prevention and treatment of vomiting caused by cytotoxic drugs and opioid use post-op

Answer 12

Serotonin Receptor Antagonists: Ondansetron

Question 13

L2: Which pharmacologic agent(s)? Effective in treating cholera toxin and traveler’s diarrhea, may worsen Shigella infection

Answer 13

Opioids

Question 14

L2: Which pharmacologic agent(s)? Facilitates stool passage by absorption of water and bulk expansion; best approximate physiologic function

Answer 14

Fiber/Bulk Forming Laxative (Psyllium)

Question 15

L2: Which pharmacologic agent(s)? First line agent in pregnancy for mild to moderate nausea

Answer 15

Pyridoxine (Vitamin B6)

Question 16

L2: Which pharmacologic agent(s)? First-line anti-emetic in pregnancy with suppression of vestibular system and vomiting center

Answer 16

Doxylamine (H1 Antagonist)

Question 17

L2: Which pharmacologic agent(s)? Greatest efficacy in reducing nausea and emesis in pregnant patients without major congenital abnormalities

Answer 17

Ondansetron

Question 18

L2: Which pharmacologic agent(s)? Increase peristalsis by causing low-grade inflammation in bowel, may cause severe cramping or electrolyte abnormalities

Answer 18

Stimulants/Irritants (Bisacodyl, senna, castor oil)

Question 19

L2: Which pharmacologic agent(s)? May be effective in reducing the anticipatory component of vomiting

Answer 19

Benzodiazepines

Question 20

L2: Which pharmacologic agent(s)? Most commonly used for mild to moderate constipation, should be avoided in renal dysfunction

Answer 20

Milk of Magnesia (Magnesium oxide), magnesium citrate

Question 21

L2: Which pharmacologic agent(s)? Most widely abused class used to relieve constipation

Answer 21

Stimulants/Irritants (Bisacodyl, senna, castor oil)

Question 22

L2: Which pharmacologic agent(s)? Nonabsorbable ions that lead to osmotic water retention to incresase peristalsis

Answer 22

Saline

Question 23

L2: Which pharmacologic agent(s)? Peripherally acting opioid antagonists used in treatment of non-cancer pain refractory to other treatment

Answer 23

Methylnaltrexone, Naloxegol

Question 24

L2: Which pharmacologic agent(s)? Possible anti-emetic action by suppressing peri-tumoral inflammation and prostaglandin production

Answer 24

Dexamethasone

Question 25

L2: Which pharmacologic agent(s)? Unknown mechanism, prophylactic against emesis in chemotherapy patients refractory to other agents

Answer 25

Dronabinol

Question 26

L2: Which pharmacologic agent(s)? Use in fecal compaction only

Answer 26

Phosphate enema

Question 27

L2: Which pharmacologic agent(s)? Used for bowel cleansing in surgical, endoscopic, or radiologic procedures

Answer 27

Polyethylene Glycol

Question 28

L2: Which pharmacologic agent(s)? Used for mild to moderate diarrhea; theoretically adsorb irritating toxins

Answer 28

Adsorbents (Bismuth, Kaolin, Pectin)

Question 29

L2: Which pharmacologic agent(s)? Used for motion sickness and post-op emesis

Answer 29

Antihistamines

Question 30

L2: Which pharmacologic agent(s)? Used in women (under age 55) with IBS and constipation as their predominant symptom, refractory to conventional therapies

Answer 30

Tegaserod

Question 31

L2: Which pharmacologic agent(s)? Used in women with severe IBS with diarrhea as their prominent symptom refractory to conventional therapies

Answer 31

Alosetron

Question 32

L2: Which pharmacologic agent(s)? Useful for initiating defecation reflex in neonates or pediatric patients

Answer 32

Glycerin suppository

Question 33

L2: Which pharmacologic agent(s)? Useful in treating diarrhea (absorbs water) and treating constipation (prevents fecal desiccation)

Answer 33

Polycarbophil

Question 34

L3: Name 2 opioids used as anti-diarrheal agents

Answer 34

Loperamide, diphenoxylate

Question 35

L3: Name 3 stimulant/irritants that may help alleviate constipation

Answer 35

Bisacodyl, senna, castor oil

Question 36

L4: Name 4 antihistamines used as anti-emetic agents

Answer 36

Meclizine, Hydroxyzine, Dimenhydrinate, Promethazine