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Gastrointestinal
Dr. Krishna 1/22/13
80
Pharmacology
Post-Graduate
01/24/2013

Additional Pharmacology Flashcards

 


 

Cards

Term
What are the four categories of antiemetics to know?
Definition
Phenothiazines
5HT3 Inhibitors
Benzamides
H1 antihistamines
Term
What is the phenothiazine to know?
Definition
Prochlorperazine
Term
What are the three 5-HT3 inhibitors to know? What do they all end in?
Definition
Ondansetron*
Granisetron
Dolasetron
-setron
Term
What is the one benzamide to know?
Definition
Metoclopramide*
Term
What are the four H1 antihistamines to know?
Definition
Diphenhydramine (Benadryl)*
Meclizine
Hyoscine
Term
Most efficacious class of antiemetic?
Definition
5-HT3 Inhibitors
Term
What antiemetic is used in patients with unrelenting nausea and vomiting, traveler's diarrhea?
Definition
Prochlorperazine
Term
MOA of Phenothiazines (Prochlorperazine)?
Definition
Blockade of dopamine receptors
Term
Adverse effects of Prochlorperazine?
Definition
Increase in dose improves antiemetic effect, but limited by adverse effects:
sedation
extrapyramidal symptoms
Term
What is the most important 5-HT3 inhibitor to know?
Definition
Ondansetron (Zofran)*
"At a party but feeling queasy? Keep ON DANCing with ONDANSetron!"
Term
MOA of Ondansetron (and the other -setrons)?
Definition
Central 5-HT3 receptor blockade in the vomiting center and chemoreceptor trigger zone
Term
What are 5-HT3 inhibitors useful for?
Definition
Highly efficacious for prevention of chemotherapy induced emesis (administered prior to chemotherapy)
Also, post-operative nausea & vomiting and radiotherapy-induced nausea & vomiting.
Long duration of action (8-10 hours)
Term
When must dosage be adjusted for the 5-HT3 inhibitors?
Definition
Dosage adjustment required in hepatic insufficiency
Term
MOA of Metoclopramide?
Definition
The antiemetic action of Metoclopramide* is due to its antagonist activity at D2 receptors in the chemoreceptor trigger zone (CTZ) in the central nervous system (CNS)—this action prevents nausea and vomiting triggered by most stimuli.
Metoclopramide also has gastroprokinetic activity that is mediated by muscarinic activity, D2 receptor antagonist activity and 5-HT4 receptor agonist activity.
Term
Adverse effects of Metoclopramide?
Definition
Avoid high doses due to extrapyramidal side effects** Knocks out dopamine and induces Parkinsonian effects
Term
What is Metoclopramide useful for?
Definition
Prevention of chemotherapy induced emesis.
Gastroperesis (acts on gastric smooth muscle to accelerate GI emptying).
(Also increased lower esophageal sphincter tone to prevent gastric reflux)***KNOW THIS FOR KRISNA!
Term
How are the H1 antihistamines used to prevent nausea & vomiting?
Definition
H1 antihistamines are combined with other antiemetics for the prevention of motion sickness.
Term
Adverse effects of H1 antihistamines?
Definition
Use is limited by sedation, dizziness, confusion, dry mouth, and urinary retention (spillover to anti-muscarinic effects)
Term
Four types of laxatives?
Definition
Bulk-forming laxatives
Stool surfactant agents (softeners)
Osmotic laxatives
Stimulant laxatives
Term
What two drugs have huge side effects of constipation and need laxatives for treatment?**
What laxative is used to treat these conditions?
Definition
Morphine
Verapamil
Use Docusate, a stool softener
Term
Name a Bulk-forming laxative?
Definition
Psyllium (nonabsorbably agents that increase water retention and stool bulk; this distends the bowel and stimulates peristalsis)
Term
Name a Stimulant laxative?
Definition
Senna (acts directly on intestinal smooth muscle to increase peristalsis)
Term
Name a Stool softener?
Definition
Docusate (emulsifies stool, softening it and making its passage easier)
Term
Name two Osmotic laxatives? (In FA, but not covered in class much)
Definition
Magnesium citrate*
Lactulose*
Term
What class of drugs are the most effective antidiarrheal agents?
Definition
Opioids (and their derivatives)
Term
What are the two opioids to know for treating diarrhea?
Definition
Diphenoxylate*
Loperamide*
Term
General MOA of opioid antidiarrheal agents?
Definition
These are derivatives of an opioid that slow GI peristaltic activity through actions of peripheral opioid receptors. This prolongs the transit time of intestinal contents.
Term
What opioid antidiarrheal has sedative effects?
Definition
Diphenoxylate* - it has peripheral and CNS opiate effects
It is formulated with an antimuscarinic alkaloid (atropine) to reduce abuse - results in patient with anti-muscarinic side effects (blurriness, dry mouth) if abused.
Term
What opioid antidiarrheal has peripheral opiate effects ONLY?
Definition
Loperamide*
Term
What opiod would be given to a patient with unrelenting diarrhea for the last 72 hours (traveler's diarrhea) who has had little or no sleep?**
Definition
Give Diphenoxylate because it has peripheral & CNS opiate effects**
It has sedative effects so that the patient can sleep.
Term
What antisecretory agent helps in treatment of diarrhea?
Definition
Bismuth* subsalicylate
Term
What are the four classes of drugs used to treat IBD?
Definition
Aminosalicylates
Corticosteroids
Immunosuppressive antimetabolites
Monoclonal antibodies
Term
Into what two major subtypes is IBD usually divided?
Definition
Ulcerative colitis
Crohn's disease
Term
What is the aminosalicylate used to treat IBD?
Definition
Sulfasalazine*
Term
MOA of Sulfasalazine*?
Definition
Acts as an anti-inflammatory drug (5-aminosalicylic acid) and antibacterial (sulfapyridine).
Term
Where does Sulfasalazine* work better?
Definition
It works much better against the symptoms of ulcerative colitis thatn Crohn's disease, since Crohn's often involves the small bowel, where the drug is not active.
Term
What are the Mesalamine compounds to know?
Definition
Pentasa (time release)
Asacol
Rowasa
Term
MOA of Mesalamine compounds?
Definition
These release 5-aminosalicyclic acid to have an anti-inflammatory effect. Also a free radical scavenger or inhibitor of TNF.
Term
What corticosteroids could you use to treat IBD?
Definition
Prednisone/Prednisolone
Methylprednisolone
Hydrocortisone
Term
What are the five immunosuppressants to know for treating IBD?
Definition
Azathioprine*
6-Mercaptopurine*
Methotrexate*
Cyclosporine
Infliximab*
Term
What BRM is used to treat IBD?
Definition
Infliximab*
This is a LAST RESORT for treating IBD (noted for treating Crohn's specifically)
Term
MOA of Infliximab*?
Definition
Monoclonal antibody to TNF-alpha. Inhibition of induction of pro-inflammatory cytokines (IL-1, IL-6)
Term
Algorithm for treatment of IBD?
Definition
(Drugs should be used in this order)
Aminosalicylates (Sulfasalazine*)
Antibiotics
Non-systemic steroids
Systemic corticosteroids
Immunosuppressive antimetabolites (Azathioprine*, Methotrexate*, Cyclosporine*)
Monoclonal antibodies (Infliximab*)
Surgery
Term
What four treatments are used to relieve Irritable Bowel Syndrome?
Definition
Make dietary modifications
Antispasmodic agents
Antidiarrheal agents
Antidepressants - TCAs & SSRIs
Term
What two antispasmodic agents are used in IBS?
Definition
Dicyclomine
Scopolomine* (motion sickness drug)
Term
What treatments are used to relieve Gastroesophageal Reflux Disease (GERD)?
Definition
Lifestyle changes
Antacids
H2 antagonists
Proton pump inhibitors (PPIs)
Term
What treatment is most effective in treating GERD? What treatment is least effective?
Definition
PPIs are most efficacious because it knocks out the hydrogen-potassium pump. Antacids are the least efficacious because they provide symptomatic relief only.
Term
What condition can GERD progress into?
Definition
Peptic ulcer disease
They are lesions in the stomach or duodenum occurring as a result of excessive pepsin and acid activity.
Term
What is Zollinger-Ellison syndrome?
Definition
Hypersecretion due to a gastrin-secreting tumor
Term
Causative factors in peptic ulcer disease?
Definition
NSAID use (NSAIDS remove the cytoprotective prostaglandins)
Alcohol
Smoking
Stress
H. pylori infection (90% of patients)
Term
What is the most efficacious way to diagnose an H. pylori infection?
Definition
Urea breath test (UBT)
Stool antigen test (second best test)
Term
What are the therapeutic objective to treating peptic ulcers?
Definition
1. Elimination of H. pylori
2. Reduction of gastric acid secretion or acid neutralization
3. Protection of gastric mucosa from further damage
Term
What five categories of drugs are used to treat peptic ulcer disease?
Definition
Antacids
H2 antagonists
Cytoprotective agents
PPIs
Antimicrobial agents
Term
What is the triple therapy to treat peptic ulcer disease?
Definition
PPI plus two antimicrobial agents
Term
MOA of antacids?
Definition
Gastric antacids are weak bases that react with gastric HCl to form a salt and water -> increased gastric pH.
Effective SYMPTOMATIC treatment for pain of peptic ulceration. ONLY neutralizes gastric acid that has ALREADY been released; will not prevent gastric acid release and has no cytoprotective effect.
Term
Name the active ingredients of antacids?
Definition
Aluminum hydroxide*
Magnesium hydroxide*
Calcium carbonate* (Rolaids, Tums)
Magnesium carbonate
Sodium bicarbonate
Term
What are the antacids to know?
Definition
Aluminum hydroxide + Magnesium hydroxide (Maalox)
Aluminum hydroxide + Magnesium hydroxide + Simethicone (Mylanta)
Aluminum hydroxide + Magnesium carbonate (Gaviscon)
Calcium carbonate* (Rolaids, Tums)
Term
Adverse effects of antacids?
Definition
Prolonged use -> systemic alkalosis
Diarrhea
May interfere with drug absorption (by making environment alkaline) -> some drugs require acid environment (Digosin, Ketoconazole, Isoniazid)
Increased gastric pH may cause premature dissolution of enteric-coated drugs
Certain drugs may form complexes with aluminum, magnesium, and calcium
Significant reduction in drug bioavailability (Tetracycline, Ciprofloxacillin)
Term
What drug does antacids increase the acidity and toxicity of?
Definition
Quinidine (a basic drug) -> absorption is INCREASED in an alkaline environment
Term
Four H2 antagonists to know?
Definition
Cimetidine* (Tagamet)
Ranitidine* (Zantac)
Nazatidine* (Axid)
Famotidine* (Pepcid)
Term
Most potent H2 antagonist?
Lest potent H2 antagonist?
Definition
Famotidine*
Cimetidine*
Term
MOA of H2 antagonists in reducing gastric acid?
Definition
Competitively and reversibly bind H2 receptors on parietal cells
Diminish cytosolic cAMP production and secretion of histamine-stimulated gastric acid
Complete inhibition of gastric acid secretion induced by histamine or gastrin.
Partial inhibition of gastric acid secretion induced by ACh.
Term
Adverse effects of Cimetidine*?
Definition
Cimetidine is a strong inhibitor of the cytochrome P-450 system and therefore can slow the metabolism of drugs normally broken down through this system. Decreases metabolism of Warfarin, Phonobarbital, Phenytoin, Diazepam, Propranolol
Term
What other adverse effect may Cimetidine* cause?
Definition
Gynecomastia** and decreased libido (due to its antiandrogenic effects)
Term
What H2 antagonist can be used at a lower dose and doesn't mess with cytochrome P-450 much?
Definition
Ranitidine* (Zantac)
Term
What drug is the most efficacious in treating Peptic ulcer disease?
Definition
PPIs
Term
Three PPIs to know for treating Peptic ulcer disease?
Definition
Omeprazole* (Prilosec)
Lansoprazole* (Prevacid)
Esomeprazole* (Nexium)
-prazole
Term
MOA of PPIs?
Definition
Irreversible inhibitors of H+/K+ ATPase.
Marked suppression of acid secretion by stomach parietal cells.
Term
When should PPIs be taken?
Definition
Most effective when taken 30 minutes before meals
Term
What two PPIs have dangerous adverse effects? What are the adverse effects?
Definition
Omeprazole* and Esomeprazole* selectively inhibit cytochrome P-450. can slow the metabolism of drugs normally broken down through this system. Decreases metabolism of Warfarin, Phenytoin, Diazepam. Rabeprazole* and Pantoprazole* have almost no interaction with the cytochrome P-450 system.
Term
What drug acts as a cytoprotective agent?
Definition
Bismuth* Subsalicylate (Pepto-Bismol)
Term
How does Bismuth* work?
Definition
Bismuct compounds appear to work by selectively binding to an ulcer, coating it and protecting it from acid and pepsin.
Term
What other therapeutic actions are possible?
Definition
Bismuch compounds may have some antimicrobial activity against H. pylori.
Term
What is the drug regimen for eradication of H. pylori?
Definition
Combination therapy ("triple therapy")
PPI + Metronidazole or Amoxicillin + Clarithromycin
Term
What PPI is used in the combination therapy regimen?
Definition
Omeprazole*

Regimen:
Omeprazole*
Metronidazole or Amoxicillin
Clarithromycin
Term
Why is Clarithromycin used in the combination therapy to eliminate H. pylori?
Definition
Clarithromycin doesn't interact with the cytochrome P450 system
Term
When would a Bismuth*-based regimen be used to eliminate H. pylori?
Definition
If there is an open ulcer bed
Term
What is the Bismuth*-based four drug regimen for eliminating H. pylori?
Definition
Omeprazole*
Bismuth* subsalicylate
Metronidazole
Tetracycline
Term
If a patient gets an ulcer from taking NSAIDs, what do you do?
Definition
If the patient needs to continue taking NSAIDS, put them on a COX-2 inhibitor. If cardiac issues, give a single dose of PPI.
Term
What is the DOC to treat Zollinger-Ellison (ZE) syndrome?
Definition
PPIs
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