What are the 6 disorders of the GI tract?
Acidity Nausea Diarrhea Constipation Irritation Inflammation
What are the 2 acid related disorders?
Gastro-esophageal reflux disease (GERD)- acid from stomach reflexes into esophagus, this burns the esophagus (heart burn) and can eventually cause serious damage
What are buffering agents?
Mg, Al hydroxide
Simple to use, but not strong enough for many people
Use these because H + base -> neutral
Side effects are diarrhea from Mg and constipation from Ca, Al
What are the 2 agents that decrease acid secretion?
H2 antagonists- ranitidine, reversible antagonists at H2 receptors, tolerance can develop
AE: well tolerated
Proton pump inhibitors- omeprazole, irreversible inhibition of the proton pump, binds to active proton pumps and inhibits
AE: well tolerated, long term use concerns, increase pH concerns about reduced absorption of nutrients, alteration in GI flora
What are anticholinergics used in upper GI pharm?
Rarely used- poor efficacy, many side effects
What are gastrin antagonists role in upper GI pharmacology?
What are the 2 mucosal defence agents?
- Prostaglandins- misoprostol
- Coating agents- sucralfate, bismuth subsalicylate (pepto bismol)
What are prostaglandins?
Promotes secretion of mucous/bicarb
Inhibits acid secretion
AE: diarrhea, abdominal cramping, induced abortion
What are the 2 types of coating agents?
Sucralfate- aluminum hydroxide + sucrose sulfate
Forms paste and stimulates mucous and bicarbonate secretion
AE: Al causes constipation
Bismuth salts- bismuth subsalicylate
Forms protective barrier on ulcer
Enhances mucous and bicarbonate secretion
Inhibits growth of H pylori and adherence to mucosa
What are the 2 main causes of ulcer?
Helicobacter pylori (H pylori)- produces inflammatory changes in mucosa, impairs mucosal defence, increases acid secretion If you have bacteria causing this you just kill it but before this was discovered ulcers wouldn’t go away
How do you eradicate H pylori?
Combinations of drugs usually used Proton pump inhibitor plus combinations of 2 or 3 antibiotics Common antibiotics used: Amoxicillin Clarithromycin Tetracycline Metronidazole Bismuth
What are the 4 future directions for curing ulcers? (Since antibiotics are becoming resistant)
Reversible proton pump inhibitors- toxicity issues have slowed development
Faster onset PPIs- remove coating, stim proton pumps
New motility agents for GERD- GABA agonists, glutamate antagonists
Target the acid “pocket”- alginic acid and buffers