gastrointestinal pharm

Question 1

GERD

Answer 1

1) chronic condition of acid reflux
2) inappropriate relaxation of lower esophageal sphincter
3) indigestion and heartburn
- chest pain
- hoarseness
- asthma
- esophageal and dental erosion

Question 2

barretts esophagus

Answer 2

1) metaplasia
2) early stage - GERD treatment
3) any dysplasia - resection, cryotherapy, surgery

Question 3

peptic ucler disease

Answer 3

1) erosion of lining from acid/pepsin
2) involvement of G- bacteria h. pylori in most cases
- cytokine production
3) often NSAID usage implicated in etiology of disease
- can interrupt gastric mucosa integrity

Question 4

common gastric disease mechnisms

Answer 4

1) arachidonic acid => leukotrienes
2) COX 1 and 2 are targeted by NSAIDs
- COX1 mediates gastric integrity, which you don’t want inhibited (by NSAID or h pylori)
- COX 2 inhibitors are better

Question 5

acid seretion

Answer 5

1) gastrin - G cell
- gastric distension
2) histamine - enterochromaffin like cell
- gastrin induces histamine
3) acetylcholine - vagal innervation

Question 6

drugs modifying acid levels

Answer 6

1) PPI
- omepraxole, lansoprazole
- slow acting - longer term
2) histamine receptor antagonists
- cimetidine, famotidine
- faster acting - medium term
3) anticholinergics
- propantheline
- not regularly used
4) antacids
- magnesium oxide, sodium bicarbonate
- immediate effect - short term

Question 7

zantac

Answer 7

1) do not take Zantac - FDA requests removal of all ranitidine
2) breakdown products on storage are toxic and carcinogenic

Question 8

adverse reactions

Answer 8

1) PPIs are generally well tolerated
- slight increase in gastrin over time
- some disruption of Ca2+ and Mg2+ metabolism
- potential interaction with CYP2C19 and CYP3A4 mediated drugs including diazepam, clopidogrel, st johns wort
2) non specific adverse reactions from cimetidine
- other H2 antagonists have no sig CYP interactions
- but cytochrome metabolism alters systemic level of many drugs
- anti-androgenic
3) Mg salts
- mess with digestions, diarrhea,
4) AL salts
- constipations

Question 9

other drugs for GERD and PUD

Answer 9

1) prostaglandin E1 - misoprostol
- increase mucosal blood flow and mucus secretion, reduce histamine and acid secretion
- treats NSAID lesions
2) antibiotics
- clarithromycin, amoxycillin, metronidazole
- usually in combination with two plus PPI or H2 antagonist, treats h. pylori
3) physical protectants
- sodium alginate, sucralfate
- gel covering either gastric fluid or mucosal walls

Question 10

gastroparesis

Answer 10

1) associated with diabetes
2) enhanced by GLP-1 receptor agonist (ozempic)
3) delayed gastric empty
4) aim of therapy is to
- promote motility
- decrease gastric emptying time
5) drugs for treatment of GERD and anti emetic drugs useful

Question 11

dental considerations

Answer 11

1) avoid administration of gastric irritants
- NSAIDS, erythromycin, corticosteroids
2) antacids may reduce absorption of many drugs
3) cimetidine competes with other drugs metabolized by CYP450 including lidocaine and diazepam
4) positional reflex alleviated by chair at 45%

Question 12

anti-emetic drugs

Answer 12

1) broad variety of drugs with targets from the brain to the GIT crossover with prokinetic drugs
2) commonly used during anti cancer therapy
- because potential for nausea and emesis
- dimenhydrinate, metoclopramide, etc. etc.

Question 13

bethanecol

Answer 13

1) muscarinic receptor agonists

Question 14

neostigmine

Answer 14

Ach inhib

Question 15

meocloparamine

Answer 15

dopamine receptor antagonist

Question 16

erythromycin

Answer 16

motilin agonists

Question 17

antidiarrheal drugs

Answer 17

1) diarrhea caused by drugs, infection or toxin
- remove source
2) opiates for non bacterial / non parasitic disease
- loperamide and diphenoxylate cant pass BBB
3) bismuth subsalicylate
- coats irritates mucosa, binds toxins

Question 18

inflammatory bowel disease

Answer 18

1) crohns disease and UI
2) primarily young adults
3) presentation with blood diarrhea and abdominal pain
4) flare ups may be associated with aphthous like lesions
- up to 20%
- but with granularity or uneven margins
5) oral ulceration in crohns but not colitis may precede systemic diagnosis of GI disease
- normally resolved when crohns is treated

Question 19

treatment with antiinflammatory drugs

Answer 19

1) sulfasalazine metabolized to %-aminosalicylate (mesalazine/mesalamine)
2) steroids
3) immunosuppressants
- consider med consult
4) anti-TNF alpha antibodies - infliximab (med consult)
5) ulmus fulva (slippery elm), aloe vera, boswellia (frankincense), curcumin - herbal remedy

Question 20

IBS

Answer 20

1) cause unknown
2) potentially stress, iet, or lifestyle
2) bloating cramping, diarrhea

Question 21

dental considerations of IBD or IBS

Answer 21

1)be careful with NSAIDs which can reduce wound healing and increase chance of infection