GI disorders: intro and gerd

Question 1

Parietal cells can be stimulated to release acid by what 3 things:

Answer 1

Gastrin
Acetylcholine (Ach)
Histamine

Question 2

Stimuli for gastrin secretion?

Answer 2

1. Small peptides and amino acids in the lumen of the stomach
2. Distention of the stomach
3. Vagal stimulation

Question 3

what inhibits gastrin?

Answer 3

H+ in the lumen of the stomach

Somatostatin

Question 4

acid production: cephalic response

Answer 4

Response to sight, smell, taste, and anticipation of food (mediated by Ach)

Question 5

acid production: gastric

Answer 5

Induced by the presence of food in the stomach

Distention of the stomach  vagal response  gastrin release

Question 6

acid production:intestinal

Answer 6

Due to entry of food into the lumen of the small intestine

Amino acids have positive feedback on gastrin release

Question 7

epidemiology of Gerd

Answer 7

more common in whites and blacks

Question 8

Gastro esophageal reflux disease

Answer 8

Effortless movement of gastric contents from the stomach to the esophagus leading to symptoms and signs of injury to the esophagus, oropharynx, larynx, and respiratory tract

Question 9

pathophysiology of Gerd

Answer 9

Develops when acidic contents reflux into the esophagus and remain there long enough to cause damage . common in the first trimester of pregnancy due to relaxation of LES

Question 10

for reflux to occur

Answer 10

LES (lower esophageal sphincter) must be relaxed enough to allow passage of fluid and
Pressure must be greater in the stomach than the esophagus must allow this flow

Question 11

risk factors for Gerd increasing intragastric

Answer 11

Delayed gastric emptying  increase gastric volume and frequency of reflux
Smoking and high fat meals  increased gastric volume and emptying

Question 12

risk factors for Gerd: intra-abdominal pressure

Answer 12

Obesity and pregnancy

Tight fitting clothes

Question 13

Foods that decrease LES pressure

Answer 13

Fatty meal
Carminatives (peppermint, spearmint)
Ethanol
Garlic 
Chocolate 
Caffeine (coffee, tea, cola)
Chili Peppers 
Onions

Question 14

foods that increase LES pressure

Answer 14

High protein meals

Question 15

drugs that decrease LES pressure

Answer 15

Anticholinergics (TCAs)
Barbituates 
Caffeine 
DHP CCBs
Dopamine
Estrogen
Ethanol  
Nitrates
Progesterone 
Tetracycline 
Theophylline

Question 16

Direct Irritants to the esophageal mucosa:foods

Answer 16

Foods 
Spicy foods 
Orange juice 
Tomato juice 
Coffee

Question 17

Direct Irritants to the esophageal mucosa ;medications

Answer 17

Medications: NSAIDs / Aspirin 
Alendronate 
Iron 
Quinidine 
Potassium Chloride

Question 18

clinical presentation of Gerd

Answer 18

Heartburn
Burning retroperitoneal pain
Can occur anytime of day, but most frequently after meals
Water brash
Reflex salivary hypersecretion in response to esophagitis
Belching
Regurgitation
Gastric contents are returned to the mouth in the absence of nausea

Question 19

alarming symptoms of Gerd

Answer 19

May be indicative of complications 
Dysphagia
Difficulty swallowing 
Odynophagia 
Pain on swallowing 
Bleeding
Unexplained weight loss
Choking 
Chest Pain

Question 20

complications Gerd

Answer 20

Esophageal stricture
Esophageal ulceration, perforation, or bleeding
Barrett’s esophagus and esophageal adenocarcinoma

Question 21

diagnosis of Gerd

Answer 21

Clinical History 
Heartburn / acid regurgitation 
Pts with mild symptoms 
Endoscopy 
Preferred technique 
Allows exclusion of other diseases and confirms diagnosis 
Ambulatory pH / impendence monitoring 
Esophageal Manometry 
PPI Test 
Short course of PPI

Question 22

therapy for Gerd:lifestyle changes

Answer 22

Lifestyle modifications
Avoid laying down for several hours following a meal
Limit tight fitting clothes
Eat smaller meals
Avoid foods/drugs that decrease LES pressure
Weight loss
Smoking cessation
Elevating the head of the bed 6-8 inches with a foam wedge under the mattress

Question 23

antacids

Answer 23

Mechanism of action
Neutralizes gastric acid 
Dosing 
PRN 
Place in GERD therapy 
Fast symptom control 
Poorly suited for regular use 
Agents
Calcium carbonate  
Aluminum Hydroxide 
Magnesium Hydroxide 
Sodium Bicarbonate .Pepcid AC has aluminum hy and mag to counter act GI
effects

Fluroquinolones and tetracyline calcium mag ad
Alum can bind to these products and not allow them to
Absorb. Levothroxine also can not be absorbed

Question 24

antacids

Answer 24

Adverse Effects
Constipation 
More common with aluminum and calcium 
Diarrhea 
More common with magnesium 
Aluminum and magnesium containing antacids can accumulate in renal failure 
Pregnancy Category C
Drug Interactions 
In general, schedule around other medications by 2-4 hours to avoid interactions don't work on receptor stressed

Question 25

histamine 2 agonists

Answer 25

``` Mechanism of action: Blocks H2 receptor activation on parietal cells and prevents histamine-stimulated acid production Better at blocking nocturnal acid production than food-stimulated secretion Dosing: BID to QID Place in GERD Therapy Mild to moderate GERD Agents Cimetidine Usually avoided due to higher incidence of ADEs and drug interactions Ranitidine Famotidine Nizatidine (rarely used) ``` Might not be good choice for those who have problems After meals Ranitidine-zantac Famotidine-pepcid Most commonly used

Question 26

proton pump inhibitors: mechanism of action and dosing

Answer 26

``` Mechanism of action Irreversibly inhibits the H+/K+ ATPase (proton pump) of the parietal cell Blocks all acid production Only inhibits activated pumps Takes 3-5 days to reach clinical effect Dosing Dosed daily to BID Administer before meals ```

Question 27

proton pump inhibitors: drug interactions and adverse effects

Answer 27

Place in GERD Therapy Adverse Effects Diarrhea or constipation Vitamin B12 deficiency Controversial association with C. Diff infection Drugs Interactions Clopidogrel  decreases pro-drug activation Less with pantoprazole

Question 28

Prokinetics: mechanism of action, adverse effects, place in therapy

Answer 28

Metoclopramide Mechanism Antidopaminergic and stimulation of cholinergic receptors Increases LES pressure Accelerates gastric emptying Adverse effects EPS (extrapyramidal symptoms) Akathesia Contraindicated in patients with GI bleed, perforation or obstruction, pheochromocytoma, other drugs that cause EPS, and/or seizure disorders Place in therapy Great for adjunctive therapy in select patients – not ideal for monotherapy

Question 29

treatment of intermittent and mild heartburn

Answer 29

LSM Antacids: PRN or after meals/at bedtime Over-the-counter doses of PPIs or H2 Blockers If symptoms persist  move to mild treatment

Question 30

mild symptoms no warning signs

Answer 30

LSM H2 Blockers for 6-12 weeks or PPI for 4-8 weeks If no relief with H2 Blocker  try PPI If no relief with PPI  increase dose or refer for endoscopy

Question 31

moderate to severe symptoms no warning signs

Answer 31

LSM PPI for 4-16 weeks (full doses) If no relief  increase PPI dose or add-on H2 blocker or refer for endoscopy

Question 32

warning signs or known erosive esophagitis

Answer 32

LSM Refer patient with warning signs for endoscopy PPI at healing doses for 4-16 weeks

Question 33

H2 blockers

Answer 33

H2 blockers will not keep you from getting Acid production because there are multiple Ways that acid gets produced Histamine is going to work on parietal cell And cause it to release acid M3 and gastrin in atrum can also produce acid Stools less fluid. Unknow why it causes diarrhea Sometimes more diarrhea /more studies to back up use of zantac in preg Pregnancy some use tums although cate B