What does GERD stand for
Gastroesophageal reflux disease
Parietal cells in the epithelial lining of the stomach secrete
hydrochloric acid (HCl) through the H+/K+ -adenosine triphosphatase (ATPase) pump known as the proton pump
The pump, and secretion of HCl, is stimulated by histamine, ACh and the hormone gastrin which has the added role of
stimulating stomach muscle contracentrations to aid in digestion
How is acidic gastric contents normally prevented from backflow into the esophagus
by a protective ring of muscle fibers called lower esophageal sphincter (LES)
Patients with GERD have reduced
LES pressure (muscle tone), and gastric contents can backflow into the esophagus
GERD symptoms
heartburn (daytime or nocturnal), hypersalivation and regurgitation of acidic contents into the mouth or throat
How is GERD diagnosed
based on patient-reported symptoms: duration, daytime and/or nocturnal occurrence, frequency ≥ 2 times/week and risk factors (family history, diet and eating habits)
Drugs that can worse GERD
aspirin/NSAID, bisphosphonates, dabigatran, estrogen products, fish oil products, iron supplements, nicotine replacement therapy, steroids, tetracyclines
Patients should be referred for further evaluation if
they do not respond to lifestyle modifications and/or 2 weeks of OTC self treatment
For frequent (≥ 2 times/week) or severe GERD, what is the initial treatment
8 week course of a PPI
Maintenance treatment of GERD
PPI at the lowest effective dose
(alternative: H2RA, if there is no erosive esophagitis)
MOA of antacids
works by neutralizing gastric acid (producing salt and water) which increases gastric pH
Since antacids do not require systemic absorption, they provide relief within
minutes but the duration of relief is short (30- 60 mins)
Brand name of calcium carbonate
Tums
Brand name of calcium carbonate + magnesium
Mylanta Supreme
Brand name of calcium carbonate + simethicone
Maalox Advanced Maximum Strength
Brand name of magnesium hydroxide
Milk of Magnesium
Brand name of magnesium hydroxide + aluminum + simethicone
Mylanta Maximum Supreme
Brand name of sodium bicarbonate/aspirin/citric acid
Alka-Seltzer
Aluminum and magnesium can
accumulate with severe renal dysfunction (not recommended if CrCl < 30 mL/min)
Side effects of calcium
constipation, bloating, bleching
Side effects of aluminum
constipation, hypophosphatemia
Side effects of magnesium
loose stools
MOA of H2RA
reversibly inhibit H2 receptors on gastric parietal cells which decrease gastric acid secretion
Brand name for famotidine
Pepcid AC
Brand name for cimetidine
Tagamet HB
Onset of relief for H2RA
within 60 mins, duration 4-10 hours
Which H2RA was removed from the market in 2020
ranitidine (Zantac)
MOA of PPIs
irreversibly bind to the gastric H+/K+ ATPase pump in parietal cells
(this shuts down the pump and blocks gastric acid secretion)
Which PPIs do you take before breakfast
esomeprazole, lansoprazole, omeprazole
Brand name for esomeprazole
Nexium
Brand name for lansoprazole
Prevacid
Brand name for omeprazole
Prilosec
Brand name for dexlansoprazole
Dexilant
Brand name for pantoprazole
Protonix
Brand name for rabeprazole
Aciphex
PPIs may diminish the therapeutic effect of which medication
clopidogrel
Side effects of IV Protonix
thrombophlebitis, severe skin reactions (SJS/TEN)
Onset of PPIs
1-3 hours, duration > 24 hours
Which PPIs are available IV
pantoprazole and esomeprazole
Which PPIs capsules can be opened, mixed in applesauce and swallowed immediately
dexlansoprazole, esomeprazole, lansoprazole, omeprazole and rabeprazole
(everyone but pantoprazole)
What vitamin deficiency can occur with long-term PPI use
vitamin B12
Which PPIs come in ODT formulation
lansoprazole, omeprazole
Which H2RA comes in an injection
famotidine
MOA of metoclopramide
dopamine antagonist
PPIs inhibit what enzyme
CYP2C19
PPIs can increase the levels of
citalopram, phenytoin, tacrolimus, voriconazole and warfarin
How does peptic ulcer disease (PUD) occur
occurs when there is mucosal erosion within the GI tract
Where does peptic ulcer usually occur
in the duodenum
(small percentage occur in the stomach)
Three most common causes of PUD
H. pylori, NSAIDs and stress ulcer
What is H. pylori
a spiral-shaped, pH-sensitive, gram-negative bacterium that lives in the acidic environment of the stomach
Primary symptom of PUD
dyspepsia, a gastric pain that can feel like a gnawing or burning sensation in the middle or upper stomach
If the ulcer is in the duodenal, what are the symptoms
pain is typically worse 2-3 hours after eating, eating food or taking antacids lessens the pain
With gastric ulcers, what are the symptoms
eating generally worsens the pain
Diagnostic test for H. pylori
urea breath test (UBT)
First line treatment for H.pylori
quadruple therapy
When is triple therapy treatment for H.pylori considered first-line
only if clarithromycin resistance rates are low (<15%) and the patient has no previous history of taking a macrolide antibiotic for any reason
What medications are in the quadruple therapy treatment
bismuth subsalicylate 300 mg QID + metronidazole 250-550 mg QID + tetracycline 500 mg QID + PPI BID
(take for 10-14 days)
What drugs does Pylera contain
bismuth subcitrate potassium 420 mg + metronidazole 375 mg + tetracycline 375 mg
What drugs are in concomitant therapy for H.pylori
amoxicillin 1000 mg BID + clarithromycin 500 mg BID + metronidazole 500 mg BID + PPI BID
(take for 10-14 days)
What drugs are in clarithromycin triple therapy
amoxicillin 1000 mg BID + clarithromycin 500 mg BID + PPI BID
(take for 14 days)
What drugs are in Prevpac
amoxicillin + clarithromycin + lansoprazole
How does NSAIDs cause ulcers
direct irritation of the gastric epithelium and systemic inhibition of prostaglandin synthesis
Risk factors for NSAID induced ulcers
age > 60 y/o, history of PUD, high-dose NSAID, using > 1 NSAID, concomitant use of anticoagulants, steroids, SSRIs or SNRIs
Brand name of naproxen/esomeprazole
Vimovo
Brand name of ibuprofen/famotidine
Duexis
Brand name of diclofenac/misoprostol
Arthrotec
Brand name of misoprostol
Cytotec
MOA of misoprostol
prostaglandin E1 analog that replaces the gastro-protective prostaglandins removed by NSAIDs
MOA of sucralfate
sucrose-sulfate-aluminum complex and can interact with albumin and fibrinogen to form a physical barrier over an ulcer
Brand name of sucralfate
Carafate
Side effects of misoprostol
diarrhea, abdominal pain
Side effects of sucralfate
constipation