-
Parietal cell receptors
- -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
-
Enterochromaffin like cells
ECL cells
-what receptors do they have?
Para enteric NS--> Ach--> M1-->
Somatostatin--> ST2 receptor--> (inhibitory)
G-cells--> Gastrin--> CCKb receptor
-
Parietal cell proton pump
K/H-ATPase!
- pump H+ out, K+ in
- use ATP
-
H2 blockers
"--dine"
- Cimetidine
- Ranitidine
- Famotidine
- Nizatidine
-
Cimetidine
- 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!
-
Ranitidine
- 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!
-
Famotidine
- H2 blocker
- -reversible block H2 receptor--> decrease H+release by parietal cells
-USE- peptic ulcer, gastritis, mild GERD
-
Nizatidine
- H2 blocker
- -reversible block H2 receptor--> decrease H+release by parietal cells
-USE- peptic ulcer, gastritis, mild GERD
-
Omeprazole
- PPI
- irreversibly inhibit H/K-ATPase in gastric parietal cells
USE- Peptic ulcer, Gastritis, GERD, Zollinger Ellison Syndrome
-
Lansoprazole
- PPI
- irreversibly inhibit H/K-ATPase in gastric parietal cells
USE- Peptic ulcer, Gastritis, GERD, Zollinger Ellison Syndrome
-
Bismuth
- 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
-
Sucralfate
- 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
-
Triple therapy regimen for H. pylori
Metronidazole + Amoxicillin + Bismuth
+/ PPI
or (tetracycline instead of Amoxicillin)
-
Misoprostol
- 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)
-
Pirenzepine
- 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!)
-
Propantheline
- 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!)
-
Octreotide
Somatostatin analog
- USE- acute variceal bleeds, Acromegaly
- - VIPoma, Carcinoid tumors
SE- nausea, cramps, steatorrhea (malabsorption)
-
Antacids
- -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!!!!
-
AlOH
- 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
-
MgOH
- 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
-
CaCO3
- 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
-
Infliximab
monoclonal antibody to TNF
USE- Crohn's disease, Rheumatoid arthritis
- SE- Resp infection (reactivation of latent TB)
- fever, hypotension
-
Sufasalazine
- 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!
-
Ondansetron
- 5-HT3 antagonist
- -powerful centrally acting antiemetic!
USE- nausea/vomiting in post-op, chemotherapy
SE- headache, constipation
-
Metoclopramide
- 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!
|
|