GI Pharm Flashcards
H2 Receptor Antagonists (4)
1) Cimetidine
2) Ranitidine
3) Famotidine
4) Nizatidine
When are H2 receptor antagonist effects most pronounced?
At night due to nocturnal acid secretion (which depends largely on histamine)
Nizatidine: Class? Pharmacokinetics?
1) H2 receptor Antagonist
2) Great bioavailbility dt reduced first pass hepatic metabolism
Serum half life is 1-4 hours
H+K+ ATPase
Proton pump
How often should H2 receptor antagonist be used for GERD?
<3x per week
If doctor decides to use H2 receptor antagonist for peptic ulcer, when should they be given?
At night
H2 receptor antagonist contraindicated?
Preganant women; crosses the placenta and gets into breast milk
Two H2 receptor antagonists that effect hepatic metabolism of many drugs?
Cimetidine and Ranitidine
Proton Pump Inhibitors (6)
1) Omeprazole
2) Esomprazole
3) Lansoprazole
4) dexlansoprazole
5) Pantoprazole
6) Rabeprazole
PPIs: how do they work?
1) Prodrugs!– require acid environment; activated drug binds with H, K atapase and irreversibly inactivates the enzyme
Most potent H2 receptor antagonist?
Famotidine
How should PPI be used?
On empty stomach before meals
Triple therapy of Hpylori associated ulcers?
1) PPI
2) Amoxicillin
3) Clarithromycin or metronidazole bid
PPI adverse reactions in hospitalized patients?
C. difficile
Sucralfate: Use? MOA? Drug drug interactions?
1) Ulcers
2) **Promotes mucosal defense; **Requires acidic activation
3) so do not give with PPI or H2);
Thought to selectively bind necrotic ulcer tissue and acts as barrier to acid, pepsin and bile
Drug that promotes mucosal defense? Which drugs should it not be given with?
1) Sucralfate
2) PPI or H2 antagonist
Colloidal Bismuth Compounds: MOA? Use?
1) Bind to ulcer, coat it and protect it
2) Ulcers (direct antimicrobial activity against H pylori)
(High rates of ulcer healing when combined with tetracyclines and metronidazole)
Misoprostol: MOA? Use? Contraindication?
1) Prostoglandin analog; both mucosal and acid inhibitory properties; reduces histamine stimulated cAMP production
2) NSAID induced ulcers
3) will ABORT in pregnant woman
3 functions of metoclopramide? Use? MOA? Side effects?
1a) Inc. esophageal clearance
b) Raises LES pressure
c) Inc. gastric emptying
2) used for gastric motor problems
3) DA receptor antagonist
4) Extrapyramidal
DM II patient on medication for “gastric motility” develops a tremor– drug? MOA?
Metoclopramide
Dopamine antagonist
Lubiprostone: use? MOA? side effects?
1) Inc. motility; soften stools (constipation)
2) FA derivative from prostoglandin– producing chloride rich secretions
3) Can’t use in children
Prostoglandin derivative that cannot be used in children?
Lubiprostone
Laxative used before colonoscopy
Polyethylene Glycol
Diphenoxylate and loperamide: MOA?
Inhibits ACh release
Two drugs that inhibit ACh release
Diphenoxylate and Loperamide
ACh inhibitor that has potential for addiction?
Diphenoxylate
Pain associated with IBS: drug class? Two drugs?
1) Tricyclic antidepressants
2) Amitriptyline and desipramine
Amitriptyline: Use? What is it?
1) IBS
2) Tricyclic antidepressant
Desipramine: Use? What is it?
1) IBS
2) Tricyclic antidepressant
Alosetron: Use? MOA?
1) Severe IBS with diarrhea
2) Seretonin antagonist
5-HT3 antagonist in GI tract
Alosetron
Mesalamine (5-ASA): use? MOA?
1) UC
2) Bowel specific aminosalicylate
First line treatment of mild to moderate UC?
Mesalamine (5-ASA)
Steroid that is released in distal ileum and colon?
Budesonide
Steroid with high first pass metabolism?
Budesonide
Antimetabolite used primarly for Crohn’s?
Methotrexate
Natalizumab: MOA? Side effect? use?
1) Anti integrin antibody
2) Progressive multifocal leukoencephalopathy (caused by JC virus)
3) Moderate to severe Crohn’s in patients who have failed other treatments
Anti seretonin drugs suffix?
“setron”
4 Anti 5-HT3 drugs?
1) Ondansetron
2) Granisetron
3) Dolasetron
4) Palonosetron
What drugs are used to enhance efficacy of antiemetic drugs? 2
1) Dexamethasone
2) aprepitant
2 neurokinen receptor antagonists? Use?
1) Fosaprepitant
2) Aprepitant
Antiemetics
Antihistamine with fewest anticholinergic effects?
Meclizine
3 antihistamines used for motion sickness?
1) Diphenhydramine
2) Dimenhydrinate
3) Meclizine
Protease Inhibitors (3)
Tealprevir
Boceprevir
Simeprevir
All end in “previr”; Previr think protease
Telaprevir
protease inhibitor
Simeprevir
Protease inhibitor
Boceprevir
Protease Inhibitor (previr think protease inhibitor)
Ribavirin
Nucleoside analog for HCV
Used to treat HCV? MOA?
1) Ribavirin
2) Nucleoside analog
Sofosbuvir
NucleoTide analog
NucleoTide analog
Sofosbuvir
Entecavir
HBV; nucleoside analog
Lamivudine
HBV; nucleoside analog
Telbivudine
HBV; nucleoside analog
Tenofovir
HBV; nucleoside analog
Adefovir
HBV; nucleoside analog
Treatment of HBV? 2 classes?
Interferons and Nucleoside analogs
How do nucleoside analogs inhibit HBV DNA synthesis?
Inhibit HBV DNA polymerase
Goal of HCV?
Sustained viral response
Goal of HBV?
Seroconversion from HBeAg
Treatment of HCV types 2 and 3?
Interferons and ribavirin
MOA of Ribavirin?
Inhibits GTP synthesis and capping of viral mRNA
New drug to treat HCV 2 and 3? MOA?
1) Sofosbuvir
2) NucleoTide analog that inhibits RNA polymerase
3 protease inhibitors for HCV 1 and 4? MOA?
Teleprevir
Boceprevir
Simeprevir
Inhibit Viral protein processing
Metoclopramide: Use? MOA? Toxicities?
1) Inc. gastric emptying; inc esoph clearance; raises LESP in DM patients
2) Antagonism of D2 receptors
3) CNS; extrapyramidal; psych
Drug that increases gastric emptying by antagonizes D2 receptors?
Metoclopramide
Lubiprostone: Use? MOA? Toxicity?
1) Softens stool (chronic constipation)
2) FA deriv of prostoglandin E1 (prost) that activates chloride channels
3) Do not use in children
Drug for chronic diarrhea that activates chloride channels in GI epithelium?
Lubiprostone (do not give to children)
Psyllium?
Bulk forming laxative
methylcellulose?
Bulk forming laxative
Docusate?
stool softener
Polyethylene glycol?
Osmotic laxative
MgOH2; sorbitol; lactulose
Osmotic laxatives
Two drugs used for rapid bowel evacuation?
Magnesium citrate and sodium phosphate
Bisacodyl?
Stimulant laxative (Coyl of doody)
Diphenoxylate? MOA? Side effects
1) antidiarrheal
2) opioid agonist: inhibit ACh release
3) CNS and dependence
Want to start patient on antidiarrheal. Pt. says he has an addictive personality. Drug?
1) Loperamide because unlike diphenoxylate, it does not cross the BBB and has no potential for addiction
Antidiarrheals that act on ACh release from presynaptic vessels?
1) Diphenoxylate
2) Loperamide
How do we treat pain in IBS?
Low doses of TCA (amitriptyline or desipramine)
TCAs used to pain in IBS?
1) Amitriptyline
2) Desipramine
5HT3 antagonist for IBS?
Alosetron
Alosetron
5 HT3 antagonist
Salazines: use?
First line for ulcerative colitis (and used in Crohn’s disease that affects colon or distal ileum)
Controlled release corticosteroid that acts on distal ileum and colon? Other?
1) Budesonide
2) High first pass metabolism
Budesonide: What is it? Other?
1) Controlled release corticosteroid that acts on terminal ileum and colon
2) High first pass metabolism
3 antimetabolites?
1) Azathioprine
2) 6MP
3) Methotrexate
Antimetabolite with uncertain effect on ulcerative colitis?
Methotrexate
Most significant side effects of anti TNF?
Opportunistic infection due to suppression of helper T cell (type 1 inflammatory response)
Antiintegrin? toxicity?
1) Natalizumab (Natali can’t seem to hold onto anything; no integrin)
2) Progressive multifocal leukoencephalopathy
“setrons”
1) 5 HT3 antagonist
2) Antiemetics
What drugs increase therapy of 5HT3 antagonists
Corticosteroids and NK1 receptor antagonist (aprepitant)
Aprepitant and Fosaprepitant (Prepitants)
1) Neurokinin 1 antagonists
2) Used in combination with 5 HT3 antagonist and corticosteroids
Neurokinin 1 antagonists (2)
1) Aprepitant
2) Fosaprepitant
prepitants
H1 antihistamine use?
Motion Sickness
H1 antihistamines (3) why one over the other? use?
1) Motion sickness
2) Diphenhydramine (benadryl); dimenhydrinate; meclizine
3) Meclizine has less anticholinergic properties and less sedating
H1 antihistamine with fewer anticholinergic properties and less sedation properties?
Meclizine
