GI Pharmacology Flashcards
Sodium Bicarbonate
Antacid: neutralize gastric acid & stimulate PGE2
Duration of Action: 1-2hrs
Rate of Reactivity: FAST
Common Adverse Effects: Reduced drug bioavailability and enteric infection
Specific Adverse Effects: Metabolic alkalosis, excessive NaCl absorption, gas/bloating
Indication: GERD, peptic ulcers, dyspepsia
Calcium Carbonate
Antacid: neutralize gastric acid & stimulate PGE2
Duration of Action: 1-2hrs
Rate of Reactivity: MODERATE
Common Adverse Effects: Reduced drug bioavailability and enteric infection
Specific Adverse Effects: acid rebound, gas/bloating, hypercalcemia (hi doses), hypophosphatemia (rare)
Indication: GERD, peptic ulcers, dyspepsia
Magnesium Hydroxide
Antacid: neutralize gastric acid & stimulate PGE2
Duration of Action: 1-2hrs
Rate of Reactivity: SLOW
Common Adverse Effects: Reduced drug bioavailability and enteric infection
Specific Adverse Effects: Osmotic diarrhea, hypermagnesemia (hi dose over extended periods of time)
Indication: GERD, peptic ulcers, dyspepsia
Aluminum Hydroxide
Antacid: neutralize gastric acid & stimulate PGE2
Duration of Action: 1-2hrs
Rate of Reactivity: SLOW
Common Adverse Effects: Reduced drug bioavailability and enteric infection
Specific Adverse Effects: constipation, Al toxicity (w/ impaired renal function), hypophosphatemia, bone resorption , hypercalcemia
Indication: GERD, peptic ulcers, dyspepsia
Cimetidine
H2-Receptor Antagonist
Duration of Action: 10hrs vs 6hrs OTC
Common Adverse Rxns: headache, diarrhea, fatigue, constipation, infection, drug kinetics, bradycardia & hypotension (only w/ IV administration)
Specific Adverse Rxns:
CNS effects = confusion, hallucinations, agitation
Endocrine effects = inhibition of androgen receptors, estradiol metabolism, increase prolactin levels
Inhibit CYP metabolism
Ranitidine
H2-Receptor Antagonist
Duration of Action: 10hrs vs 6hrs OTC
Common Adverse Rxns: headache, diarrhea, fatigue, constipation, infection, drug kinetics, bradycardia & hypotension (only w/ IV administration)
Nizatidine
H2-Receptor Antagonist
Duration of Action: 10hrs vs 6hrs OTC
Common Adverse Rxns: headache, diarrhea, fatigue, constipation, infection, drug kinetics, bradycardia & hypotension (only w/ IV administration)
Famotidine
H2-Receptor Antagonist
Duration of Action: 10hrs vs 6hrs OTC
Common Adverse Rxns: headache, diarrhea, fatigue, constipation, infection, drug kinetics, bradycardia & hypotension (only w/ IV administration)
Omeprazole
Proton Pump Inhibitor (PPI)
Duration of Action: 1dose = 24hrs, 3-4days = max effect
Common Adverse Rxns: very safe, decereased drug bioavailability, diarrhea, headache, abd pain
Adverse Rxns: decreased nutrient absorption (vitB12, iron, calcium, zinc), enteric and resp infection
Indications: GERD, peptic ulcers d/t H Pylori & NSAIDs, dyspepsia, gastritis, hypersecretory diseases (zollinger-ellison syndrome)
Lansoprazole
Proton Pump Inhibitor (PPI)
Duration of Action: 1dose = 24hrs, 3-4days = max effect
Common Adverse Rxns: very safe, decereased drug bioavailability, diarrhea, headache, abd pain
Adverse Rxns: decreased nutrient absorption (vitB12, iron, calcium, zinc), enteric and resp infection
Indications: GERD, peptic ulcers d/t H Pylori & NSAIDs, dyspepsia, gastritis, hypersecretory diseases (zollinger-ellison syndrome)
Rabeprazole
Proton Pump Inhibitor (PPI)
Duration of Action: 1dose = 24hrs, 3-4days = max effect
Common Adverse Rxns: very safe, decereased drug bioavailability, diarrhea, headache, abd pain
Adverse Rxns: decreased nutrient absorption (vitB12, iron, calcium, zinc), enteric and resp infection
Indications: GERD, peptic ulcers d/t H Pylori & NSAIDs, dyspepsia, gastritis, hypersecretory diseases (zollinger-ellison syndrome)
Esomeprazole
Proton Pump Inhibitor (PPI)
Duration of Action: 1dose = 24hrs, 3-4days = max effect
Common Adverse Rxns: very safe, decereased drug bioavailability, diarrhea, headache, abd pain
Adverse Rxns: decreased nutrient absorption (vitB12, iron, calcium, zinc), enteric and resp infection
Indications: GERD, peptic ulcers d/t H Pylori & NSAIDs, dyspepsia, gastritis, hypersecretory diseases (zollinger-ellison syndrome)
Pantoprazole
Proton Pump Inhibitor (PPI)
Duration of Action: 1dose = 24hrs, 3-4days = max effect
Common Adverse Rxns: very safe, decereased drug bioavailability, diarrhea, headache, abd pain
Adverse Rxns: decreased nutrient absorption (vitB12, iron, calcium, zinc), enteric and resp infection
Indications: GERD, peptic ulcers d/t H Pylori & NSAIDs, dyspepsia, gastritis, hypersecretory diseases (zollinger-ellison syndrome)
Misoprostol
Mucosal Protective Agent (not a physical barrier)
Prostaglandin derivative, stimulates epith cells of gastric mucosa to secrete mucus and HCO3-, decreases activation of H+/K+ ATPase in parietal cells
Duration of Action: 6hrs
Common Adverse Rxns: Cramping, diarrhea
Adverse Rxns: abortificient
Indications: NSAID-assoc ulcers
Sucralfate
Mucosal Protective Agent (forms a physical barrier)
Stimulates mucus and HCO3- production thru unknown mechanism
Duration of Action: 6hrs
Common Adverse Rxns: Constipation, impaired drug absorption
Adverse Rxns: caution w/ renal insufficient pts
Indications: used to prevent stress-related bleeding in critically ill hospitalized pts where suppression of acid not desired
Bismuth Subsalicylate (mucosal protective agent use)
Mucosal Protective Agent (forms a physical barrier)
PEPTO-BISMOL: Stimulates mucus and HCO3- production thru unknown mechanism
Duration of Action: 6hrs
Common Adverse Rxns: black stool & tongue
Adverse Rxns: high doses salicylate toxicity
Indications: dyspepsia, antibacterial actions that are useful w/ H Pylori or traveler’s diarrhea
Metoclopramide
D2 Antagonist - Prokinetic Agent (promote cx of GI sm)
(prevents dopamine from suppressing ACh release)
Indications: GERD, impaired gastric emptying, dyspepsia, antiemetic
Adverse rxns: CNS: restless, drowsy, insomnia, anxiety, parkinsonian sx (d/t dopamine antagonist action)
Bethanechol
M3 Agonist - Prokinetic Agent (promote cx of GI sm)
Indications: GERD, gastroparesis
Adverse rxns: cholinergic side effects
Neostigmine
AchE Inhibitor - Prokinetic Agent (promote cx of GI sm)
Indications: non-obstructive urinary retention or abdominal distension
Adverse rxns: cholinergic side effects
Erythromycin
Motilin Receptor Agonist - And Antibiotic
Prokinetic Agent (promote cx of GI sm)
Indication: gastroparesis
Adverse rxn: erythromycin mediated side effects
Methylcellulose
Laxative - Bulk-Forming MOA: fiber, adds bulk and retains H2O Poor absorption Indications: constipation, to minimize straining, prior to surgical/endoscopic procedures Adverse Rxn: gas/bloating
Glycerin
Laxative - Surfactant MOA: coats/penetrates fecal material Poor absorption Indications: constipation, to minimize straining, prior to surgical/endoscopic procedures Adverse Rxn: nutrient malabsorption
Lactulose
Laxative - osmotic MOA: changes osmotic pressure Poor absorption Indications: constipation, to minimize straining, prior to surgical/endoscopic procedures Adverse Rxn: gas / electrolyte flux
Senna
Laxative - ENS Stimulant MOA: leaky mucosa, Na+ uptake inhibited Poor absorption Indications: constipation, to minimize straining, prior to surgical/endoscopic procedures Adverse Rxn: GI irritation
Tegaserod
Laxative - Serotonin (5HT4) Agonist
MOA: Partial 5HT agonist (inhibits GI sensory neurons that relay pain sensation to CNS) (5HT stimulates ACh secretion and GI sm cx) 10% Absorption
Indications: chronic, idiopathic constipation: IBS constipation
NOT AVAILABLE FOR GENERAL USE
Adverse Rxn: GI and CV effects
Lubiprostone
Laxative - Chloride Channel Activator MOA: Prostaglandin Derivative Poor absorption Indications: chronic constipation Adverse Rxn: nausea, vomiting, diarrhea
Methylnaltrexone
Laxative - Mu-opioid Receptor Antagonist
MOA: blocks peripheral mu-opioid receptors
Poor CNS Penetration
Indications: opioid-induced constipation in palliative care
Adverse Rxn: abd pain, flatulence, nausea, diarrhea
Alvimopan
Laxative - Mu-opioid Receptor Antagonist
MOA: blocks peripheral mu-opioid receptors
Poor CNS Penetration
Indications: post-op ileus in hospitalized pts w/ bowel resection
Adverse Rxn: abd pain, flatulence, nausea, diarrhea
Risk of MI (so only use for 7 days)
Loperamide
Antidirrheal Agent
MOA: opioid agonist
Indications: diarrhea (IBS)
Adverse Rxns: constipation (very safe)
Diphenoxylate
Antidirrheal Agent
MOA: opioid agonist
Indications: diarrhea
Adverse Rxns: constipation (very safe)
Bismuth Subsalicylate (antidiarrheal use)
Antidirrheal Agent
MOA: inhibits PG synthesis (intestinal), absorbs toxins
Indications: non-specific diarrhea, travelers diarrhea
Adverse Rxns: salicylate toxicity
Cholestryamine
Antidirrheal Agent
MOA: binds bile acids and salts, this reduces the osmotic pressure caused by unabsorbed bile-salts
Indications: diarrhea d/t impaired bile-salt absorption in the ileum d/t chron’s disease or ileum resection
Adverse Rxns: bloating, flatus, constipation, fecal impaction, impaired fat absorption
Octreotide
Antidirrheal Agent
MOA: somatostatin receptor agonist: increase fluid absorption and decrease motility
Indications: secretory diarrhea
Adverse Rxns: impaired pancreatic secretion, decreased GI motility (nausea, pain), decreased gall bladder cx, glucose homeostasis
Ondansetron (Zofran)
Antiemetic Agent
MOA: Serotonin (5HT) antagonist
Indication: chemotherapy, post-op, post-radiation
Adverse effects: headache, dizziness, constipation, prolonged QT interval
Scopolamine
Antiemetic Agent
MOA: M1 antagonist
Indication: motion sickness
Adverse effects: antimuscarinic effects
Metoclopramide
Antiemetic Agent
MOA: D2 antagonist
Indication: chemo and radiation therapy induced nausea and vomiting
Adverse effects: extrapyramidal (PARKINSONIAN Sx)
Dimenhydrinate
Antiemetic Agent
MOA: H1 Antagonist
Indication: motion sickness
Adverse effects: drowsiness
Aprepitant
Antiemetic Agent
MOA: NK antagonist
Indication: chemotherapy
Adverse effects: fatigue, dizziness, diarrhea, CYP3A4 interactions
Prochlorperazine
Antiemetic Agent
MOA: M1, D2, H1 antagonist
Indication: severe nausea and vomiting
Adverse Effects: Extrapyramidal (parkinsonian sx), drowsiness, anticholinergic
Lorazepam (Ativan)
Antiemetic Agent
MOA: GABA agonist
Indication: anxiety / chemotherapy
Adverse effects: drowsiness
Nabilone
Antiemetic Agent
MOA: Cannabinoid agonist
Indication: chemotherapy
Adverse effects: dysphoria, sedation, increased appetite
Dexamethasone
Antiemetic Agent
MOA: glucocorticoid agonist - increases effectiveness of serotonin antagonists
Indication: chemotherapy, post-op, post-radiation
Adverse effects: weight gain, water retention, other corticosteroid effects
Alosetron
Antidiarrheal used to tx IBS (diarrhea predominant)
MOA: 5HT3 Antagonist
Indications: IBS-diarrhea predominant (WOMEN ONLY)
Adverse effects: constipation, ischemic colitis
Sulfasalazine
Aminosalicylate - used to topically tx IBD
1st line agent for mild to moderate ulcerative colitis
MOA: inhibition of COX production of PGs, interferes w/ inflammatory cytokine production (IL-1), inhibits NF-kB signaling (transcription factor)
Administration: oral Target: colon
Modification: Azo linked (N-N)
Adverse effects: Nausea, GI upset, headache, arthralgia, myalgia, bone marrow suppression, malaise
(40% of pts can’t tolerate this drug)
Mesalamine-Pentasa
Aminosalicylate - used to topically tx IBD
1st line agent for mild to moderate ulcerative colitis
MOA: inhibition of COX production of PGs, interferes w/ inflammatory cytokine production (IL-1), inhibits NF-kB signaling (transcription factor)
Administration: oral Target: throughout intestine
Modification: time release microgranules
Adverse effects: headache, dizziness, abdominal pain
Mesalamine-Asacol
Aminosalicylate - used to topically tx IBD
MOA: inhibition of COX production of PGs, interferes w/ inflammatory cytokine production (IL-1), inhibits NF-kB signaling (transcription factor)
Administration: oral Target: ileum/proximal colon
Modification: pH sensitive resin
Mesalamine-Rowasa/Canasa
Aminosalicylate - used to topically tx IBD
MOA: inhibition of COX production of PGs, interferes w/ inflammatory cytokine production (IL-1), inhibits NF-kB signaling (transcription factor)
Administration: enema / suppository
Target: rectum / sigmoid colon
Modification: high concentrations
Prednisone
Glucocorticoid (steroid) - can be used to tx IBD
Indication: moderate to severe active IBD
MOA: suppression of inflammatory cytokines (TNFalpha, IL-1), suppression of chemokines (IL-8), suppression of adhesion molecules, suppression of signal transduction molecules that mediate cytokine and chemokine activities (NOS, PLA2, COX2, NFkB)
Administration: IV / oral / suppository
Methotrexate
Antimetabolite: anti-cancer drug used to tx IBD
Indications: maintenance of Chron’s remission
MOA: inhibits DHFR resulting in impaired cellular proliferation (inhibition of immune cell proliferation)
Administration: IM, subQ, orally
Adverse effects: low dose side effects uncommon:
bone marrow depression, megaloblastic anemia
Inflixamab
Monoclonal Ab - used to tx IBD
Indication: moderate to severe IBD
MOA: binds and sequesters TNFalpha: can’t stimulate production of inflammatory cytokines: inhibits immune response.
Adverse effects: infection (6%)
Azathioprine
Immunosuppressive, antineoplastic, antibiotic drugs function by interfering with nucleotide synthesis:
azathioprine inhibits de novo purine synthesis
Indications: maintenance of IBD remission
Adverse effects: nausea, vomiting, bone barrow suppression
