GI drugs

• -para (enteric NS)-->Ach--> M3--> Gq--> IP3
• -food-->antrum G cells--> Gastrin-->CCKb receptor--> Gq-ECL cell--> Histamine--> H2 receptor--> Gs-->cAMP
• -PGs-->Gi-->decrease cAMP
• -Somatostatin-->Gi--> decrease cAMP

Para enteric NS--> Ach--> M1-->

Somatostatin--> ST2 receptor--> (inhibitory)

G-cells--> Gastrin--> CCKb receptor

K/H-ATPase!

• pump H+ out, K+ in
• use ATP

"--dine"

• Cimetidine
• Ranitidine
• Famotidine
• Nizatidine

• H2 blocker
• -reversible block H2 receptor--> decrease H+ release by parietal cells
• -inhibit CYPs!!
• -antiandrogenic!
• -cross BBB, placenta!

USE- peptic ulcer, gastritis, mild GERD

• SE- antiandrogenic effect!- prolactin release, gynecomastia, impotence, decrease libido in males
• -confusion, dizziness, headaches (cross BBB)
• Decrease renal CRN excretion!

• H2 blocker
• -reversible block H2 receptor--> decrease H+release by parietal cells
• -decrease CRN clearance!

USE- peptic ulcer, gastritis, mild GERD

SE-decrease renal CRN excretion!

• H2 blocker
• -reversible block H2 receptor--> decrease H+release by parietal cells

-USE- peptic ulcer, gastritis, mild GERD

• H2 blocker
• -reversible block H2 receptor--> decrease H+release by parietal cells

-USE- peptic ulcer, gastritis, mild GERD

• PPI
• irreversibly inhibit H/K-ATPase in gastric parietal cells

USE- Peptic ulcer, Gastritis, GERD, Zollinger Ellison Syndrome

• PPI
• irreversibly inhibit H/K-ATPase in gastric parietal cells

USE- Peptic ulcer, Gastritis, GERD, Zollinger Ellison Syndrome

• Bind to gastric ulcer base
• -provide physical protection
• -allow HCO3- secretion to reestablish pH gradient in mucosal layer

USE- increase ulcer healing, traveler's diarrhea

• Bind to gastric ulcer base
• -provide physical protection
• -allow HCO3- secretion to reestablish pH gradient in mucosal layer

USE- increase ulcer healing, traveler's diarrhea

Metronidazole + Amoxicillin + Bismuth

+/ PPI

or (tetracycline instead of Amoxicillin)

• PGE1 analog
• -Increase production, secretion of gastric mucous barrier.
• -Decrease acid production

• USE- prevent NSAID-induced peptic ulcers
• -maintain PDA! (Tetralogy of Fellot, Complete Transposition)
• -Induce LABOR!

• SE- Diarrhea
• do NOT use in women of childbearing potential (abortifacient)

• Muscarinic antagonist
• -block M1 on ECL cells--> decrease Histamine secretion
• -block M3 on parietal cells--> decrease H+ secretion

USE- Peptic ulcer (rarely used)

• SE- tachycardia, dry mouth, cycloplegia
• (3C's!)

• Muscarinic antagonist
• -block M1 on ECL cells--> decrease Histamine secretion
• -block M3 on parietal cells--> decrease H+ secretion

USE- Peptic ulcer (rarely used)

SE- tachycardia, dry mouth, cycloplegia (3C's!)

Somatostatin analog

• USE- acute variceal bleeds, Acromegaly
• - VIPoma, Carcinoid tumors

SE- nausea, cramps, steatorrhea (malabsorption)

• AlOH
• MgOH
• CaCO3

• -can affect absorption, bioavailability, urinary excretion of other drugs by:
• -altering gastric and urinary pH
• -delaying gastric emptying
• -can chelate, decrease efficacy of drugs
• (ex) Tetracycline
• -can cause HYPOKALEMIA!!!!

• Antiacid
• -can affect absorption, bioavailability, urinary excretion of other drugs by:
• -altering gastric and urinary pH
• -delaying gastric emptying
• -can chelate, decrease efficacy of drugs (ex) Tetracycline
• -can cause HYPOKALEMIA!!!!

• specific SE- Constipation, Hypophosphatemia
• Proximal muscle weakness, osteodystrophy, seizures

• Antiacid
• -can affect absorption, bioavailability, urinary excretion of other drugs by:
• -altering gastric and urinary pH
• -delaying gastric emptying
• -can chelate, decrease efficacy of drugs (ex) Tetracycline
• -can cause HYPOKALEMIA!!!!

specific SE- diarrhea, hyporeflexia, hypotension, cardiac arrest

• Antiacid
• -can affect absorption, bioavailability, urinary excretion of other drugs by:
• -altering gastric and urinary pH
• -delaying gastric emptying
• -can chelate, decrease efficacy of drugs (ex) Tetracycline
• -can cause HYPOKALEMIA!!!!

Specific SE- hypercalcemia, rebound acid increase

monoclonal antibody to TNF

USE- Crohn's disease, Rheumatoid arthritis

• SE- Resp infection (reactivation of latent TB)
• fever, hypotension

• combo of Sufapyridine + 5-aminosalicylic acid
• (antibiotic + anti-inflammatory)
• -activated by colonic bacteria

USE-Ulcerative colitis, Crohn's disease

SE-Malaise, nausea, sulfonamide hypersensitivity, reversible oligospermia!

• 5-HT3 antagonist
• -powerful centrally acting antiemetic!

USE- nausea/vomiting in post-op, chemotherapy

SE- headache, constipation

• D2 receptor antagonist
• -increase resting tone, contractility, Lower esophageal sphincter tone, mobility
• -does NOT influence colon transport time

USE- Diabetic neuropathy illeus, post-op gastroparesis

• SE- parkinsonian effects! restlessness, drowsiness, fatigue, depression, nausea, diarrhea.
• -drug interaction w/ Digoxin, DM agents
• do NOT use in small bowel obstruction!