peptic diseases pharmacology Flashcards
Pharmacological treatment of PU categories?
Agents affecting gastric secretion
Mucosal Protective Agents
Post secretoryagents
Agents affecting gastric secretion?
PPI
Anti H2 -histamines
Mucosal Protective Agents?
Prostaglandins
Post secretoryagents?
Anti-acids
receptors on parietal cells?
H2 histamin (Gi)
colicystokinin B (gastrin, Gq)
M3 (Ach, Gq)
E2 (PG, Gi)
PPI targets?
inhibitors of the gastric H+, K+-ATPase
covalent inhibition
PPI mechanism of action?
p/o prodrug blood entrocytes canaliculi (acid inviroment) activation H+, K+-ATPase covalent inhibition
PPI paradox?
lond lasting effect
short half life (0.5-2h)
How to prevent degradation of proton pump inhibitors by acid
enteric coated prodrug
PPI drug examples
omeprazole lansoprazole rabeprazole pantoprazole (prazole)
PPI side effects?
generaly safe
common side effects:
Diarrhea, headache, and abdominal pain
prolonged: subnormal B12 levels (intrinsic factor, PH)
Respiratory and Enteric Infections due to PH change
rebound hypersecretion of gastric acid upon discontinuation of therapy
histamine receptors characteristics?
H1 + H2 are peripherial
H1 s.muscle, endothel, brain (Gq)
H2 gastric mucosa, cardiac muscle, mast cells, brain (Gs)
both basolaterl in parietal cells
H2-receptor antagonists indications?
Gastric and duodenal ulcers
Uncomplicated GERD
Stress ulcers (prevent the occurrence)
H2-receptor antagonists examples?
cimetidine (1) > rantidine (4-10) > nizatidine (4-10) > famotidine (20-50)
most usable are rentidine anf famotidien
H2 receptor antagonists most common side effects?
Diarrhea headache fatigue myalgias constipation