GI drugs Flashcards
Famotidine
-MOA
-Adverse Reactions
-antacid
-H2 receptor ANTAGONIST (reversible competitive inhibition)
-reduce H ions and pepsin
-Rebound hypersecretion of gastric acid
-urine excretion
Omeprazole
-MOA
-Adverse Reaction
-antacid
-proton pump inhibitor
-irreversible
-partial inhibition of drugs eliminated by cP450 enzymes
-diarrhea
-rebound hyper secretion
dissolution occurs in duodenum
Misoprostal
-MOA
-Adverse reactions
-antacid
-methyl ester analog of PGE1
-effects localized to stomach –> rapid metabolism of liver
-diarrhea, prokinetic properties of colon
-primarily used for NSAID induced ulceration
Antacid (TUMS)
-MOA
-Adverse reactions
-antacid
-chemicallly neutralized HCl
-inactivation of pepsin and binding of bile salts
-induce synthsis of mucosal protectants
-numerous drug interactions (give 2h before or after other drugs)
-fast acting, cleared from stomach 30min
Sucralfate
-MOA
-adverse reaction
-antacids
-disaccharide aluminum hydroxide-binds to damage epithelial cells
-depends on acidic environment for activation
-binds to many drugs
-Duodenal >gastric ulcers
-promotes angiogenesis and epithelization
Bethanechol
MOA
Adverse reaction
-prokinetic
-cholinergic agonist at muscarinic receptors
-increases strength of contractions but minimal effects on coordination of SI contractions
-abdominal cramps, diarrhea, salivation, bradycardia
Metoclopramide
MOA
Adverse reactions
-prokinetic
-central and peripheral antidopaminergic effect and is a direct and indirect stimulator of cholinergic receptors
-increases tone of LES
-increases force and frequency of gastric antral contractions
-relaxes pyloric sphincter
-UPPER GI peristalsis
-dose dependent CNS effects
-renal and hepatic excretion
-atropine and opioids antagonize
Domperidone
MOA
Adverse reactions
-prokinetic
-dopamine antagonist
-similar to metoclopramide but no cholinergic activity
-does not cross BBB- still have effects at CTZ
Cisapride
-MOA
–Adverse reaction
-prokinetic
-indirect stimulation of cholinergic nerves mediated by serotonin
-myocardia/sudden cardiac arrest
-increased activity of entire GI tract
Erythromycin
MOA
Adverse reaction
-macrolide antibiotic
-prokinetic
-effects mimic motilin
-LES pressures increase, uncorrdinated stomach contractions, and increased SI motility
-GI upset
-Tolerance due to downregulation of motilin receptors
Ranitidine
MOA
prokinetic
H2 receptor ANTAGONIST
inhibits anticholinesterase activity
Gastrin
Stimulus
Secretion
Action
-protein, distension, nerve (acid INHIBITS release)
-G cells of the antrum, duodenum and jejunum
-stimulates –> gastric acid secretion and mucosal growth
Cholecystokinin
Stimulus
Secretion
Action
-protein, fat, acid
-I cells of duodenal and jejunal mucosa
-stimulates: pancreatic enzyme secretion, pancreatic bicarb secretion, gall bladder contraction, growth of exocrine pancreas
-INHIBITS: gastric emptying and inhibit feeding centers in the brain –> prevents overeating
Secretin
Stimulus
Secretion
Action
-acid, fat
-S cells of duodenal mucosa
-Stimulates: pepsin secretion, pancreatic bicarb secretion, billiary bicarb secretion, growth of exocrine pancreas
-INHIBITS: gastric acid secretion
Gastric inhibitory peptide
Stimulus
Secretion
Action
-protein, fat, carbs
-K cells of the duodenum and jejunum
-Stimulates: insulin release
-INHIBITS: gastric acid secretion, mild effect on decreasing gastric emptying
Motilin
Stimulus
Secretion
Action
-fasting
-M cells of the stomach and upper duodenum
-Stimulates: gastric and intestinal motility
Somatostatin
Secretion
Action
-D cells in the pyloric antrum and duodenum
-INHIBIT: gastric acid production
