gastrointestinal pharm Flashcards
GERD
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
barretts esophagus
1) metaplasia
2) early stage - GERD treatment
3) any dysplasia - resection, cryotherapy, surgery
peptic ucler disease
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
common gastric disease mechnisms
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
acid seretion
1) gastrin - G cell
- gastric distension
2) histamine - enterochromaffin like cell
- gastrin induces histamine
3) acetylcholine - vagal innervation
drugs modifying acid levels
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
zantac
1) do not take Zantac - FDA requests removal of all ranitidine
2) breakdown products on storage are toxic and carcinogenic
adverse reactions
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
other drugs for GERD and PUD
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
gastroparesis
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
dental considerations
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%
anti-emetic drugs
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.
bethanecol
1) muscarinic receptor agonists
neostigmine
Ach inhib
meocloparamine
dopamine receptor antagonist
erythromycin
motilin agonists
antidiarrheal drugs
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
inflammatory bowel disease
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
treatment with antiinflammatory drugs
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
IBS
1) cause unknown
2) potentially stress, iet, or lifestyle
2) bloating cramping, diarrhea
dental considerations of IBD or IBS
1)be careful with NSAIDs which can reduce wound healing and increase chance of infection
