GI Drugs

Question 1

Meds that cause GERD,

Answer 1

calcium channel blockers, glucocorticoids, muscle relaxants, theophylline, oral bronchodialators, diazepam, nicotine, etoh, coffee, chocolate, mint, fatty foods

Question 2

risk factors for ulcers

Answer 2

H. pylori, OTC pain meds (aspirin and ibu)
Etoh
Smoing
Family Hx

Question 3

4 types of antacids

Answer 3

aluminum salts
magnesium salts
calcium salts
sodium bicarbonate
don't use antacids chronically

Question 4

Aluminum Salts

Answer 4

constipating
mag can counteract constipation
aluminum toxicity
aluminum carbonate (basaljel), hydroxide salt:AlternaGEL, combination with mag: Gaviscon, Maalox, Mylanta, Di-Gel

Question 5

Magnesium salts

Answer 5

often cause diarrhea

dangerous with renal failure, can result in mag accumulation

Question 6

Calcium Salts

Answer 6

may cause kidney stones
long duration of acid action can cause rebound hyperacidity
TUMS
stay away from it

Question 7

Sodium bicarbonate

Answer 7

high solubility
buffers acidic properties of HCL
quick onset, short duration
may cause metabolic alkalosis
high sodium content (CHF, HTN, renal insuf)

Question 8

ppi therapy should

Answer 8

elinimate symptoms
heal erosive esophagitis
prevent the relapse of erosive esophagitis

Question 9

PPI

Answer 9

wait 2-6 weeks before increasing dose
OTC is more expensive than rx
hates esomeprazole
give 1h before meals

Question 10

H2 receptor antagonist

Answer 10

reversible competitive inhibitor of H2 receptor
highly selective
effective in inhibiting nocturnal acid secretion
modest impact on meal stimulated acid secretion
ranitidine and famotidine are good,
cimetidine is bad P450 inhibitor, gynecomastia, impotence, decreased levels of other drugs (warfarin, theophylline, phentoin, ethanol)
take 1h before or after antacids
assess for allergies, imp renal or liver function

Question 11

H2 antagonist SE

Answer 11

HA, lethargy, confusion, diarrhea, urticaria, sweating, flushing, other effects, may decrease absorption of drugs that need acidic GI env

Question 12

kaolin and pectin

Answer 12

absorbent antidiarrheal, clay like powder attracts and holds onto bacteria, then thickens.for simple diarrhea, act locally in bowel

Question 13

bismuth subsalicylate

Answer 13

antisecretory and antibacterial, possibly anti-inflammatory, part of h.pylori tx, contains aspirin, CI in kids and teenagers, gray/black stools and black tongue are normal

Question 14

diphenoxylate with atropine

Answer 14

constipating, opioid activity at high doses, anticholinergic properties, slows peristalsis, d/c if abd distension, caution in older adults, hepatorenal disease

Question 15

loperamide

Answer 15

binds to opiate receptors of the intenstinal wall, slow gastric motility, diminishes fluid loss, d/c if abd distension

Question 16

oral rehydration solution

Answer 16

8 oz water, 1/4 tsp baking soda, alternate with water with salt and honey. for severe diarrhea, more salt is needed

Question 17

IBD diarrhea control

Answer 17

steroids and sulfasalazine, loperamide first

Question 18

traveler’s diarrhea

Answer 18

bismuth subsalicylate, oral antimicrobials, loperamide (immodium)

Question 19

cytoprotective agents

Answer 19

sucralfate (basic aluminum salt)- viscous gel adheres to ulcer’s crater, stress ulcer prevention and duodenal ulcer, taken on empty stomach, avoid concurrent antacid, and misoprostol - stimulates mucous and bicarb secretion(caution in renal impairment) for NSAID induced problems, cat X, GI sx, with food

Question 20

5 classes of antiemetics

Answer 20

antihistamines, phenothiazines, sedative hypnotics, cannabinoids, and 5_HT receptor antagonists

Question 21

antihistamines

Answer 21

good for motion sickness, dimenhydrinate, diphenhydramine, hydroxyzine, and meclizine, strong anticholinergic effects, CI in severe liver disease, better for long term applications

Question 22

phenothiazines

Answer 22

block dopamine receptors, sedating, have extrapyramidal effects (limiting), prochlorperazine and promethazine (fatal resp dep younger than 2, bone marrow depression)), metoclopramide (prokinetic), CI in Parkinson’s, narrow-angle glaucoma, bone marrow depression, severe CV or hepatic disease. some anticholinergic effects. may discolor urine pink/reddish-brown. additive hypontensive effects. CBC prior to initiating therapy, blood dyscrasias 4 to 10 weeks after therapy starts

Question 23

cannabinoids

Answer 23

decrease n/v/appetite stimulant, works in the CNS, may lower seizure threshold, palpitations, tachycardia, hypotension, interacts with other CNS depressants

Question 24

5-HT receptor antagonists

Answer 24

block serotonin on the peripheral vagal nerve terminals and centrally, used with chemotherapy, may mask progressive ileus, constipation, HA, fatigue

Question 25

drugs that cause peptic ulcers

Answer 25

NSAID, glucocorticoids, cytotoxic agents

Question 26

colloidal bismuth compounds

Answer 26

coats ulcer, stimulates mucus and bicaarb, direct action against H. pylori, blackening of tongue and stool, not for long term use - bismuth toxicity

Question 27

IBD therapy

Answer 27

sulfasalazine and 5-ASA, (mesalamine, active molecule) 2 moeity's, mild to moderate CD/UC

Question 28

5-ASA delivery systems

Answer 28

Pentasa - esop-rectum, for Chrons', slow release Asacol-ileum and colon effected, 60-70% Rowasa-if only rectal, avoids systemic Colazal-very expensive, colon

Question 29

antibiotics

Answer 29

CD only, not UC, metronidazole has anti-fistula properties, cipro, pouchitis biologics if metronidazole doesn't work

Question 30

steroids

Answer 30

for flare-ups, not long-term, hospitalize if can't tolerate PO, if unable to taper, try antimetabolite or infliximab, topical can be used in rectum

Question 31

azathioprine and 6 MP

Answer 31

for steroid dependent IBD, measure CBC q2w, takes months to work, major durg-drug ALLOPURINOL

Question 32

methotrexate

Answer 32

IV for active CD or maitenance of CD remission, induction with steroid withdrawal, weekly IM, monitor CBC, LFT, renal function

Question 33

cyclosporine

Answer 33

induction in UC, CD in high doses (toxicity), steroid refractory UC, used to bridge to AZA as maintenance

Question 34

infliximab

Answer 34

tnf alpha antibody - CD and UC with inadequate response to conventional tx, withdrawal concomitant steroids. avoid infection, demyelinating d/o, CHF, malignancy, screen for

Question 35

metoclopramide

Answer 35

stimulates motility in GI, postprandial and daytime heartburn, 30 min prior to meal, r/f tardive dyskinesia, don't use more than 12 weeks or when GI motility is CI (obstruction), used for GERD and diabetic gastroparesis

Question 36

PPI's interfere with absorption of...

Answer 36

Warfarin, ketoconazole, digoxin, esters of ampicillin, iron salts. inc monitoring of INR. clopidogrel efficacy dec. by 50%. lansoprazole does not interfere with warfarin

Question 37

tx of duodenal and gastric ulcers

Answer 37

PPI for 12 weeks, once daily in the am before meals, also test for H. pylori

Question 38

GERD management

Answer 38

lifestyle and antacid PRN, then H2RA, then PPI. If refractory after 4-8 weeks, inc. PPI. if symptoms gone, decrease PPI after 4 weeks. if no relief after BID, referral to gastroenterologist or if endoscopy shows erosive disease. failure to achieve symptom relief after 3 months, gastroenterology referral.

Question 39

alarm symptoms that require endoscopy

Answer 39

dysphagia, painful swallowing, noncardiac chest pain, weight loss, hematemesis, and choking. PPI may mask gastric CA.

Question 40

stimulant laxatives

Answer 40

``` release of prostaglandins inc cAMP concentration increases secretion of electrolytes stimulates peristalsis rapid response, short term cascara (has etoh, CI pregnancy), senna, bisacodyl, and castor oil used for reduced mobility, constipating drugs, reduced motility, ibs, neurogenic bowel caution with severe CV disease ```

Question 41

osmotic laxatives

Answer 41

draw water into intestinal lumen to inc pressure hypertonic salt-based solutions cause diffucion of fluid from the plasma inot the intestine most powerful mag hydroxide, mag citrate, PEG (CI in kids d/t electrolyte probs), used for bowel prep CI in renal insufficiency, hyper mag, hypocalcemia, heart block

Question 42

bulk producing laxatives

Answer 42

most physiological, safest, natural and semisynthetic polysaccharides and cellulose mechanical distention that increases peristalsis long-term management of simple, chronic const useful in avoiding straining to stool mgt of chronic, watery diarrhea CI narrowed esophageal or intestinal lumen and impaction watch for sugar or salt

Question 43

lubricants

Answer 43

mineral oil, retards colonic absorption of fecal water and softens stool used with fecal impaction lubricates intestines may decrease absorption of fat soluble vitamins, avoid in pregnancy r/f aspiration under 4 y.o.

Question 44

surfactants

Answer 44

stool softeners, emollient action, good for hard, dry stool, anorectal conditions, painful stool, avoiding straining, safe for all ages. no specific CI

Question 45

CI of all laxatives

Answer 45

presence of n/v or undiagnosed abd pain or bowel obstruction.

Question 46

miscellaneous

Answer 46

glycerin is local irritant, hyperosmotic, draws water. lactulose, hyperosmotic transformed to lactic acid and acetic and formic acid, lowers pH of colon. glycerin, for fecal impaction, neurogenic bowel.

Question 47

hyperosmolar considerations

Answer 47

lactulose causes hyperglycemia, caution in presence of volume depletion,

Question 48

chronic use of laxatives

Answer 48

r/f abuse and dependency, fluid and electrolyte imbalances, steatorrhea, osteomalacia, and vit and min deficiencies.