GI Flashcards
drugs that affect gastric secretion (4)
- antacids
- H2 histamine receptor antagonists
- proton pump inhibitors
- protectants
drugs that increase GI motility (2)
- laxatives
- prokinetic drugs
drugs that reduce GI motility (2)
- antidiarrheals
- anti-emetics
Zollinger-Ellison syndrome is
overactive tumors on pancreas secrete gastric and make too much gastirc acid
- G cells produce ___ in the lumen of the ___
- gastrin travels through blood vessels and binds to ___ and ___ cells.
- ECL cell releases ___ which binds to ___ cells
- parietal cells exchange ___ for K+ using ATPases
- this makes ___ acid more acidic
- high acidity triggers __ cells to produce ___ to slow the release of gastrin
- gastrin, antrum
- ECL, parietal
- histamine, parietal H+
- luminal
- D, somatostatin
Prostaglandins like ___ and ___ work with ___ to maintain mucus layer. When NSAIDs like aspirin inhibit prostaglandins, this protection is compromised and ulcers can form
- PGE2 and PGI2
- NO
- antacids prevent ___ from being secreted from ___ cells
- PPIs stop the whole ___
- H+, parietal
- ATPase
All of the following antacids have high neutralizing capacity except:
A) NaHCO3
B) CaCO3
C) Al(OH)3
D) Mg(OH)2
CaCO3
only moderate
Side effects
Al(OH)3: ___
Mg(OH)2: ___
- constipation
- diarrhea
Antacid Brand Names
AlternaGEL
Al(OH)3
Antacid Brand Names
Tums
CaCO3
Antacid Brand Names
Maalox, Mylanta
Al(OH)3 and Mg(OH)2
Antacid Brand Names
Rolaids
CaCO3 and Mg(OH)2
Brand Names
Alka-Seltzer
ASA and NaHCO3
Antacid Brand Names
Gaviscon
sodium alginate + antacids
viscous weak base
H2RAs block H2 receptors on ___ cells
parietal
H2RA
cimetidine (Tagamet)
* ___ antagonist
* reduce gastirc acid sectretion in response to histamine, ___ , and ____
- competitive
- gastrin, acetylcholine
2nd Generation H2RAs (3)
- ranitidine
- nizatidine
- famotidine
2nd Generation H2RAs Brand Names
ranitidine
Zantac
2nd Generation H2RAs Brand Names
nizatidine
Axid
2nd Generation H2RAs Brand Names
famotidine
Pepcid
2nd Generation H2RAs
- ___ antagonist
- reduce gastric acid secretion in response to histamine, gastrin, acetylcholine
- ___ half life ( ___ vs BID dosing)
- fewer effects on ___ system
- greater ___
- absorbed ___ to reduce parietal cell function
- competitive
- longer, HS
- CYP450
- potency
- quickly
PPI chemical structure name
benzimidazoles
PPI Brand Names
esomeprazole
Nexium
PPI Brand Names
omeprazole
Prilosec
racemic mixture
PPI Brand Names
lansoprazole
Prevacid
PPI Brand Names
rabeprzole
Aciphex
PPI Brand Names
pantoprazole
Protonix
PPI Brand Names
dexlansoprazole
Dexilant
T or F: esomeprazole is the R enantiomer that is more potent
False; S enantiomer
T or F: PPIs are prodrugs
True
PPI Prodrug Steps
- must be absorbed in the ___ , circulate and then be taken up by ___ cells. Leads to slow ___
- activated/protonated by ___ in the parietal cells
- ___ inhibitor of __ ATPase (Cys ___ )
- short plasma half life, but long duration due to ___ inhibition and slow turnover of ___
- hypergastrinemia occurs, and may result in rebound ___ of gastric acid upon drug ___
- SI, parietal, onset
- acidic pH
- irreversible, H+/K+, Cys813
- covalent, proton pumps
- hypersecretion, withdrawal
Hypergastrinemia definition
reduced gastric acid removes somatostatin’s inhibition of gastrin secretion
D cells get lazy since they havent had to suppress in to long
T or F: tolerance to H2 antagonists can occur
True
PPI associated fracture
Known
1. PPI therapy causes profound acid suppression
2. leads to ___
3. gastrin acts on ___ and leads to hyperplasia
4. leads to primary ____
5. increase in ___ causes increased bone ___
Theory
* PPIs decrease ___ absorption
* leads to secondary ____
- hypergastrinemia
- parathyroid gland
- hyperparathyroidism
- PTH, resorption
- Ca2+
- hyperparathyroidism
T or F: PPIs have an increased risk of dementia
False; debunked, this study used a bunch of old people
Vonoprazan is a ___ competitive acid blocker (P-CAB)
* faster ___ suppression
* not a ___
* not influenced by ___
* very stable to ___ pH
only approved in Japan
- potassium
- acid
- prodrug
- meals
- low
Mucosal Protective agents
Sucralfate
* Brand name ___
* ___ complex of sucrose
* ___ and forms protective barrier at ___ site
* ___ pH activates complex
* poorly ___
- Carafate
- aluminum hydroxide
- polymerizes ulcer
- acidic
- absorbed
Mucosal Protective agents
Misoprostol
* Brand name ___
* semi-synthetic ___ E1 derivative
* reduced acid secretion in __ cells
* cytoprotectant effects - enhanced ___ and ___ secretion
* used in combination eith chronic ____
* Adverse effects: ___ and ___
- Cytotec
- prostaglandin
- parietal
- mucus, bicarbonate
- NSAIDs
- diarrhea, abortifacient
H. Pylori and Peptic Ulcers
- converted to ___ salts and ___ acid in the GI tract
- Bismuth subsalicylate has ___, antiviral, and antisecretory activity
Uses: nausea, heartburn, indigestion, upset stomach, diarrhea - part of multi-drug therapy for ___ eradication
- Brand Name ___
- bismuth, salicylic
- antibacterial
- H. pylori
- Pepto-Bismol
H. pylori Eradication
therapy can consist of:
* bismuth salt ( ___ )
* antibiotic (4)
* H2 blocker or PPI
* Tritec ( ___ bismuth citrate)
- PeptoBismol
- metronidazole, tertracycline, amoxicillin, clarithromycin
- ranitidine
H. pylori Eradication example
metronidazole (Flagyl) 500 mg BID + omeprazole (Prilosec) 20 mg BID + clarithromycin (Biaxin) 500 mg BID for 2 weeks
Which of the following antibacterial drugs is used commonly to eradicate intestinal H pylori?
A) Cefazolin
B) Ciprofloxaz
C) Clarithromycin
D) Clindamycin
E) Vancomycin
Clarithromycin
- Enteric nervous system (ENS) - increased ___
- Extrinsic primary afferent - nausea, ___ , and pain (goes to brain)
- intrinsic primary (goes to ENS)
- peristalsis
- vomiting
Bulk and Osmotic Laxatives
- Fiber laxatives: psyllium ( ___ ), Methylcellulose ( ___ ), calcium polycarbophil ( ___ )
- PEG3350 ( ___ )
- isosmotic electrolyte solutions with PEG 3350 ( ___ )
- Metamucil
- Citrucel
- fiberCon
- MiraLAX
- GoLytely
Bulk and Osmotic Laxatives
- lactulose ( ___ ) is a non-absorbable sugar that has an ___ effect. Fermented by bacteria in the gut producing acetate which stimulates ___.
- sugar free gummies have non-absorbable sugar alcohol called ___, Forms hydrophilic mass in the presence of water
- increase water in the intestinal lumen by ___ force, leading to distention and an increase in ___
- Duphalac, osmotyic, peristalsis
- maltitol
- osmotic, peristalsis
Stool Softeners
- docusate sodium (Colace), mineral oil, glycerin
- __ and lubricants
- incorporate into stool to make passage easier and ___ water adsorption
- ___ lower bowel to reduced fecal impaction
- can decrease absorption of ___ soluble vitamins
- surfactants
- decrease
- lubricate
- fat (ADEK)
Secretory or Stimulant Laxatives
- mechanism poorly understood
- castor oil: hydrolyzed in the upper small intestine to ___ acid
- diphenylmethan derivatives: bisacodyl ( ___ )
- anthraquinones: cascara, ___ , and aloes
- irritation of the mucosa affects fluid secretion/absorption balance and induces ___
- ricinoleic
- Dulcolax
- senna
- peristalsis
Prokinetic Drugs and their receptors
- Prucalopride and Tegaserod; ___
- Erythromycin; ___
- Bethanechol; ___
- Metoclopramide; ___
- Neostigmine; ___
- 5-HT4
- Motilin
- M3
- D2
- AChE
Metoclopramide
- Brand name: ___
- Blockade of ___ receptors in the ___ plexus leads to increase ___ release
- produced anti-___ effects
- Promotes gastric ___
- can lead to acute ___ reactions
- Reglan
- D2, myenteric, ACh
- emetic
- emptying
- dystonic
Prokinetic Drugs
Opioid receptor antagonists:
Centrally acting: anti-addictive agents (3)
- Naloxone (Narcan)
- Naltrexone
- Nalmefene
Prokinetic Drugs
Peripherally acting - cannot cross ___
(3)
BBB
* Naloxegol (Movantik)
* Alvimopan (Entereg)
* Naldemedine (Symproic)
Opioid induced constipation can also be avoided by using a biased agonist such as ___
1. decrease smooth muscle ___
2. increase rectal sphincter ___
3. decreases colonic mucosa ___
Oliceridine
1. contraction
2. tone
3. secretion
Prokinetic Drugs
Prucalopride
* Brand name: ___
* __ agonist
* ___ receptor, GPCR, Gas coupled activation leads to increased ___ production and ___ activation. Releases ___
* indicated for the treatment of chronic idiopathic ___ in adults
- Motegrity
- 5HT4
- serotonin, cAMP, PKA, ACh
- constipation
Prokinetic Drugs
Tegaserod
* Brand Name: ___
* same mechanism as ___
* indicated for treatment of ___ in women under ___
- Zelnorm
- Prucalopride
- IBS-C, 65
Prokinetic Drugs
Chloride Channel Activators (3)
- Lubiprostone (Amatiza)
- Linaclotide (Linzess)
- Plecanatide (Trulace)
Prokinetic Drugs - Chloride Channel Activators
- increased chloride-rich fluid secretion into intestine
- treatment of ___
- not absorbed ___
- IBS-C
- systemically
Prokinetic Drugs - Chloride Channel Activators
Lubiprostone
* Brand name: ___
* stimulation of type ___ chloride channel ___ activator in ___
Linaclotide and Plecanatide
* Brand names: ___ and ___
* a ___ activator or ___ cyclase C ___
- Amatiza
- 2, ClC-2, small intestine
- Linzess, Trulance
- peptide, guanylate, GC-C
Prokinetic Drugs
Tenapanor
* ___ exchanger inhibitor
* exhanger is expressed on the ___ side of small bowel and colonic epithelial cells
* functions to absorb ___ from luminal contents
* trapping Na+ in the gut leads to increased ___ in the gut acclerating transit of intestinal contents
- Na+/H+ (NHE3)
- luminal
- Na+
- water
Which of the following drugs in an osmotic laxative that could be used to treat constipation?
A) aluminum hydroxide
B) diphenoxylate
C) magnesium hydroxide
D) metoclopramide
E) ranitidine
magnesium hydroxide
Which of these drugs irreversibly inhibits the H+/K+ ATPase in the parietal cells?
A) cimetidine
B) diphenoxylate
C) esomeprazole
D) metoclopramide
E) sulfasalazine
esomeprazole
Antidiarrheals
Opiates (2)
* slow ___ to increase water and electrolyte absorption
* inhibits ___ cholinergic nerves
- diphenoxylate, loperamide
- peristalsis
- presynaptic
Diphenoxylate ( + atropine = ___ )
* active in the ___
- Lomotil
- CNS
Loperamide ( ___ )
* poorly transverse the ___
* act ___ to delay gastric emptying
Imodium
* BBB
* locally
Loperamide ( ___ )
* poorly transverse the ___
* act ___ to delay gastric emptying
Imodium
* BBB
* locally
Antidiarrheals
Alosetron ( ___ )
* blocks visceral afferent pain sensation and decreases colon ___
Lotrinex
* motility
Anti-Emetics
- ___ receptor antagonists “-setron”
- block activity of ___ nerves from stomach and small intestine which activate the trigger center in the ___
- Side effect: ___
- 5-HT3
- afferent, CNS
- Constipation
Anti-Emetics
- NK1 antagonists (3)
- receptors in the ___ trigger zone
- can be combined with ___. Example ( ___ is a combination of Netupitant and palonosetron)
- Aprepitant, Netupitantm Rolapitant
- chemoreceptor
- 5-HT3
- Akynzeo
Anti-Emetics
antihistamines/anticholinergics
* Dimenhydrinate ( ___ ) = ___ - H1 antihistimine with anticholinergic properties + the stimulant chlorotheophylline in dramamine
- dramamine, diphenhydramine
Anti-Emetics
antihistamines/anticholinergics
* Meclizine ( ___ ) - H1 antihistimine with minimal ___ properties
Antivert
* anticholinergic
Anti-Emetics
antihistamines/anticholinergics
* Scopolamine - ___ receptor antagonist with significant ___ effects
- muscarinic
- anticholinergic
Anti-Emetics
Antipsychotics (4)
* ___ receptor antagonists
* ___ properties
* also has ___ and ___ effects
- metoclopramide = Reglan
- Prochlorperazine = Compazine
- Promethazine = Phenergan
- Droperidol = Inapsine
- D2 dopamine
- sedatice
- antimuscarinic, antihistamine
