GI pharm Flashcards
cimetidine
ranitidine
famotidine
nizatidine
H2 receptor antagonists:
omeprazole and the –prazoles
MOA: Irreversible inhibition of gastric-parietal cell proton pump -prodrugs that require activation in acid environment
**PK: **take before or w/ meal; metabolized in liver by P450 enzymes
Use:
- short term treatment of gastric and duodenal ulcers (esp NSAID induced)
- GERD
- tx of choice for ZE syndrome, MEN, systemic mastocytosis
- combo therapy for H. pylori
AE: inhib P450 leads to dec. clearance warfarin, benzo’s, phenytoin; elevated Gastrin levels
octreotide
Somatostatin analog (inhibits gastric and pancreatic secretion)
Used in ZE syndrome and
Portal hypertensive bleeding
Antacids
MgOH2
AlOH2
CaCO3
MOA: Neutralize gastric acid
**Use: **
- treatment dyspeptic Sx
- may hasten ulcer healing
AE:
MgOH2: diarrhea
AlOH2: constipation
CaCO3: stimulate gastrin release and acid secretion “Acid rebound”
*don’t use in renal failure
OTC
Sucralfate
MOA: Adheres to ulcer craters and forms a protective barrier
Use: Duodenal ulcer
AE: No systemic toxicity; May bind concomitant meds
reasons for non-healing ulcers
- -non-compliance
- -H. pylori infection
- -NSAID use
- -tobacco use
- -inadequate duration therapy
- -Hypersecretory state (ZE syndrome)
- -non-peptic ulcer related disease (malignancy)
Carbechol
Bethanechol
cholinergic receptor agonists
Muscarinic receptors which when activated lead increase in intracellular Ca
enhance GI motility
Metaclopromide
MOA: Dopamine receptor antagonist, 5-HT3 antagonist, 5-HT4 agonist
Use: Symptomatic relief to pts with gastric motor failure (diabetic gastroparesis), decreases hearburn in GERD, anti-emetic (cancer),
AE:
- Somnolence, nervousness, dystonia
- -parkinsonism/tardive dyskinesia
- -galctorrhea and menstrual d/o (inc. prolactin)
Tegerserod maleate
5-HT4 partial agonist; increase GI motility
constipation predominant IBS in women
erythromycin
MOA: Motilin agonist (Motilin receptors found on smooth muscle cells, when stimulated induce and amplify MMC; potent contractile element of upper GI tract)
Use:
Diabetic gastroparesis
Intestinal pseudoobstruction
Treatment of irritable bowel syndrome
Constipation predominant: bulking agent
Diarrhea predominant: antispasmodics/anticholinergics
Constipation: prokinetics
Constipation predom in women: tegerserod maleate
treatment of gastroparesis
Metoclopramide
Erythromycin
Cisparide
Botulinum toxin (intrapyloric injection)
Treatment of pancreatic insufficienc
Treatment of pancreatic insufficiency: steatorrhea when lipase output <10% normal
1) pancreatin: alcoholic extract hog pancreas
2) pancrelipase: enriched hog pancreas prep
Dosing
–With meals
–Titrated to therapeutic effect
–Higher gastric pH enhances activity
Toxicity:
- uric acid renal stones
- lactose in pills poorly tolerated in lactose intolerant pts
Bile salt therapy
1) Chenodiol: oral therapy to dissolve gallstones but limited by diarrhea
2) Ursodiol: epimer of chenodiol w/ fewer toxicities; used to dissolve gallstones and in primary biliary cirrhosis
Metronidazole, ciprofloxacin treatment in Crohn’s diseae
- Useful in mild to moderate Crohn’s disease
- induce remission
- Adjunct treatment
Sulfasalazine
MOA: Multiple sits in inflammation cascase; inhibition leukotrienes is most imp!
Use: -mild to moderate UC (maintaining remission)
AE: Due to sulfa component…
–Dose related malaise, nausea, abdominal pain
–Impaired folic acid absorption (supplements needed)
–Reversible decrease in sperm count
–Severe skin reactions, rarely (Stevens-Johnson syndrome)
–Bone marrow suppression
Sulfasalazine: 5-ASA linked with sulfapyridine which is digested in colon