GI system management Flashcards
1
Q
Oral stage of swallowing
A
- can be initiated voluntarily or involuntarily
- food bolus formed and propelled backward toward pharynx
2
Q
Pharyngeal stage of swallowing
A
- complex involuntary event activated by swallowing center
- swallowing centers stimulated, soft palate pulled upward, vocal cords approximated, epiglottis swings back, UES relaxes
3
Q
Esophageal stage of swallowing
A
- food moves down esophagus via primary peristalsis over 8-10 secs
- secondary peristalsis occurs if food is still in esophagus after primary wave
- LES is relaxed
4
Q
4 phases of proton pump secretion
A
- Basal (Interdigestive)
- Cephalic
- Gastric
- Intestinal
5
Q
Basal phase of secretion
A
- occurs at night
- <30% max acid output
- controlled via Ach and histamine
6
Q
Cephalic phase of secretion
A
- waking up in AM
- emotional/sensory stimuli produce excitation of vagal fibers
- vagal (parasympathetic) stim of parietal cells and antral G cells to produce H+ and peristalsis
7
Q
Gastric phase of secretion
A
- food enters stomach
- intragastric buffering enhances secretion by maintaining less acidic pH
8
Q
Intestinal phase of secretion
A
- food in intestine releases inhibitory factors
- <10% max acid output
9
Q
Management of diarrhea
A
- Motility inhibitors
- Bulk formers
- Probiotics
10
Q
Motility inhibitors
A
- Bismuth subsalicylate (Peptobismal)
- Diphenoxylate HCl with atropine (Lomotil)
- Loperamide (Imodium)
- Opium tincture
- Paregoric
11
Q
Mechanism of action of motility inhibitors
A
-inhibit Ach receptors (parasympathetic) to slow GI motility by promoting water absorption in large bowl
12
Q
Side effects of motility inhibitors
A
- Anticholinergic- dry mouth, urinary retention, blurred vision, tachycardia
- CNS- drowsiness, HA
13
Q
Calcium polycarbophil (Fibercon)
A
- bulk former
- absorbs water in large bowel
- produces gel-like stool
14
Q
Probiotics
A
- helpful for chronic diarrhea
- enhances microbial growth to inhibit harmful bacteria and promotes water reabsorption
- Culturelle
15
Q
Managing Nausea/Vomiting
A
- CTZ suppressors
- H1 receptor antagonists
- Metoclopramide
- Dronabinol
16
Q
Mechanism of action of CTZ suppressors
A
- most powerful antiemetic
- blocks postsynaptic dopamine receptors in chemoreceptor trigger zone (CTZ)
17
Q
Mechanism of action of H1 receptor antagonists
A
- antihistamines that cross the BBB
- mechanism not well known
- produces anticholinergic effects
18
Q
Metoclopramide
A
- antiemetic
- accelerate GI motility - promotes gastric emptying
- decreases N/V d/t GI overdistention
19
Q
CTZ suppressors
A
- antiemetics
- Benzquinamide HCl
- Bulizine HCl
- Chlorpromazine
- Diphenidol
- Droperidol
- Prochlorperazine (Compazine)
- Thiethylperazine
- Trimethobenzamide HCl
- Ondansetron HCl (Zofran)
20
Q
H1 receptor antagonists
A
- antiemetics
- Cyclizine
- Dimenhydrinate
- Diphenhydramine HCl
- Hydroxyzine
- Meclizine
21
Q
Side effects of CTZ suppressors
A
- CNS depression (foggy, tired)
- hypotension
- resp. depression
- anticholinergic
- extrapyramidal effects (rare)
22
Q
Medications for peptic ulcer disease
A
Antibiotics Bismuth subsalicylate PPI H2 receptor antagonist Sucralfate Prostaglandin E analog- Misoprostol
23
Q
Antibiotics used for peptic ulcer disease
A
- Metronidazole
- Clarithromycin
- Tetracycline
- Amoxicillin
- Levofloxacin
24
Q
Mechanism of action of proton pump inhibitors
A
inhibits proton pump to decrease H+ ions => decreases gastric acidity => increased pH promotes gastric healing
25
Proton pump inhibitors
```
Omeprazole (Prilosec)
Lansoprazol (Prevacid)
Rabeprazol (Aciphex)
Pantoprazol (Protonix)
Esomeprazole (Nexium)
Dexlansoprazole (Dexilant)
```
26
Mechanism of action of H2 receptor antagonists
-inhibits binding of histamine at receptors in parietal cells => decreased pumping of H+ ions from parietal cells into gut => decreased acid irritation
27
H2 receptor antagonists
Cimetidine (Tagamet)
Famotidine (Pepcid)
Nizatidine (Axid)
Ranitidine (Zantac)
28
Side effects of H2 receptor antagonists
- dizziness, drowsiness, confusion
- abd discomfort, diarrhea
* overall well tolerated
29
What drug interactions are notable for H2 receptor antagonists
Antacids- decrease absorption
30
What labs can be effected by H2 receptor antagonists
Prolonged PT
Thrombocytopenia
Neutropenia
31
Sucralfate
- mucosal protective agent
- forms paste-like substance that adheres to damaged mucosa to protect from acid/irritants
- can alter absorption of other drugs- take 1-2 hrs from other drugs
- take several times a day
- shown to decrease risk of aspiration pneumonia since it does not change pH of gut
32
Misoprosol
- Protaglandin E analog
- replaces protective prostaglandins that are inhibited by NSAIDs => inhibits GI mucosal breakdown
- Side effects- diarrhea, HA
33
Management of H. pylori PUD
Combo of 2 abx and 1 acid suppressor (PPI or H2) x 14 days (triple, quadruple, sequential, or salvage regimens)
34
Triple drug regimen for H. Pylori
PPI + Clarithromycin + Amoxicillin or Flagyl x 10-14 days (80% success rate)
35
Quadruple drug regimen for H. Pylori
PPI + bismuth + metronidazole + tetracycline x 14 days
| - for pts allergic to PCN or taking macrolides
36
Sequential regimen for H. Pylori
- may be more effective than triple therapy
- consider if pts recently on clarithromycin or metronidazole
- PPI + amox x 5 days, then PPI + clarithromycin + tinidazole x 5 days
37
Salvage therapy for H. Pylori
- for when initial treatment didn't work
- use quadruple therapy if not already used
- PPI + amox +levofloxacin x 10 days
38
What patients are at high risk for peptic ulcers
- prior hx of ulcers or GI bleed
- taking high dose NSAID
- taking corticosteroids or anticoagulant
39
What prophylaxis is given to patient at risk for peptic ulcers
- COX2 NSAID with PPI (high risk)
| - nonselective NSAID with PPI (moderate risk)
40
Management of duodenal ulcers
```
*more common
Sucralfate QID
or
PPI QD x 4 wks
or
H2 receptor blocker QHS x 6 wks
```
41
Management of gastric ulcers
*more concerning, complicated
H2 receptor blocker BID x 8-12 wks
or
PPI BID x 6-8 wks
42
Regimen to prevent NSAID ulcer relapse
- COX2 NSAID with PPI once daily
| - COX2 NSAID with misoprostol TID or QID
43
Management of GERD
PPI
- give in AM, 30-60 min prior to breakfast
- can do second dose prior to dinner
44
What medications can be used for both forms of IBS
- bulk-formers- Psyllium (Metamucil) and Methylcellulose (Citrucel)
- TCAs and SSRIs
45
Management of IBS-C
- 5HT4 agonists (not available in US)
- Polyethylene glycol (Miralax)
- Lubiprostone (Amitiza)
- Linaclotide (Linzess)
- Tenapanor (Ibsrela)
46
Lubiprostone (Amitiza)
- selective chloride channel activator
- increases fluid secretion into sm bowel => stim. GI motility
- side effect- benign chest tightness/SOB, resolves within 3hrs of admin
47
Linaclotide (Linzess)
- Guanylate cyclase-C agonist
- increases fluid secreation into gut by chloride and HCO3 channel activation
- decreases activation of pain-sensitive nerves
- primary adverse effect- diarrhea
48
Tenapanor (Ibsrela)
- very recently approved
- Na/H+ exchanger
- inhibits Na absorption to increase H2O in bowel => increases transit time and soften stool
49
Management of IBS-D
```
Eluxadoline (Viberzi)
Probiotics
Antidiarrheals
Rifaximin (Xifaxin)
Alosetron (Lotronex)
Loperamide
TCAs (2nd or 3rd line)
```
50
Eluxadoline (Viberzi)
* for IBS-D
- mu and kappa receptor agonist => analgesia
- delta receptor antagonist => decrease motility
- not for patient with: alcohol abuse, GI motility issues, or chronic/severe constipation
51
Alosetron (Lotronex
* for IBS-D
- 5HT3 recept. antagonist
- may cause ischemic colitis- black box warning: prescribers must be enrolled and patient has to sign agreement
52
Management of inflammatory bowel disease (IBD)
- monoclonal antibodies (TNF-alpha blockers)
| - Mesalamine-5-ASA
53
Infliximab (Remicade)
Adalimumab (Humira)
Certolizumab (Cimzia)
* IBD (mod-severe)
- monoclonal antibodies that block receptors for TNF-alpha, a key inflammatory mediator
- trend is now to use earlier in therapy
- black box warning- risk for infections like TB
54
Mesalamine-5-ASA
* IBD
- decreases inflammation
- Pentasa, Rowasa, Asacol
55
Naloxagel (Movantik)
for Opioid-Induced Constipation
56
Methylnaltrexone (Relistor)
for Opioid-Induced Constipation
| -SQ injection daily
57
PAMORA
for Opioid-Induced Constipation
