EXAM #1: GI PHARMACOLOGY III Flashcards
What is IBS?
Idiopathic relapsing disorder w/
- Abdominal pain (pain, bloating, distension)
- Constipation
- Diarrhea
- BOTH constipation and diarrhea
What is IBD?
Inflammatory Bowel Disease
- Crohn’s Disease= any part of the GI tract
- Ulcerative Colitis= limited to the distal GI tract
What is the difference between IBS and IBD?
IBS= Irritable Bowel Disease
IBD= Inflammatory Bowel Disease
- Crohn’s Disease
- Ulcerative Colitis
What is the common drug of choice to treat diarrhea in IBS?
Loperamide
What is the common drug of choice to treat constipation in IBS?
Osmotic laxatives
What is the role of tricyclic antidepressants and antispasmodics/antimuscarinics in IBS?
Pain relief
- Tricyclic antidepressants= increase 5-HT, which causes a decrease in receptor density, limiting pain
- Antispasmodics inhibit GI smooth muscle contraction and limit pain
What is the difference in pharmacological approach in IBS to targeting 5-HT4 and 5-HT3 receptors?
5-HT4= AGONIST
- Promotes NT release to result in MOTILITY w/ constipation
5-HT3= ANTAGONIST
- Block visceral pain
- Block motility
- Block secretions
- Used for DIARRHEA*
Why has Tegaserod been generally pulled off the market?
Cardiovasuclar adverse effects:
- MI
- CVA
What drug is commonly used for 5-HT3 receptor antagonism in IBS? What symptom of IBS is this used for?
Alosetron
DIARRHEA
What patient population is Alosetron used in?
Women ONLY
This drug does not work in men*
What is the serious adverse effect induced by Alosetron?
Ischemic colitis (fatal)
What are the four general categories of drugs used to treat IBD?
ASA
Glucocorticoids
Antimetabolites
Anti-TNF-a therapy
What is the mechanism of action of ASA drugs to treat IBD?
1) Inhibit COX and prostaglandins
2) Interfere with inflammatory cytokine production
3) Inhibit NF-KB signaling
What is the important feature of ASA-type drugs to remember about their efficacy?
If the drug is absorbed via a lesion in the GI tract, it will NOT work
There must be TOPICAL application i.e. it must STAY in the GI tract
What are the three strategies to keep ASA drugs in the GI tract?
- Proprietary release formula
- Chemical binding
- High concentration delivered rectally
What are the examples of ASA drugs?
Sulfasalazine
Mesalamine
What is the mechanism of action of glucocorticoids in the treatment of IBD?
Suppression of inflammatory factors
What are the examples of steroids used for IBD?
Prednisone
What is the mechanism of action of anti-metabolites for IBD?
- Inhibit proliferation of immune cells
- Immune suppression
What are the examples of anti-metabolites used to treat IBD?
Methotrexate
Azathropine
What is the mechanism of Anti-TNF-a drugs in the treatment of IBD?
- TNF-a is a cytokine that mediates the inflammatory response in IBD
- Monocolonal antibodies are administered to bind and prevent the action of TNF-a
What is the example of an anti-TNFa monoclonal antibody to treat IBD?
Infliximab
What are the first line agents for mild-moderate IBD?
Sulfasalazine
Mesalamine
What are the adverse effects of Sulfasalazine? What is important to remember about these side effects?
- Nausea
- GI upset
- Headache
- Artralgia
- Myalgia
- Bone marrow suppression
- Malaise
A sizable number of patients CANNOT tolerate these effects and will STOP using the drug
What is the indication for Prednisone?
Moderate to severe active IBD
What is the indication for Azathropine?
To maintain remission of IBD
What is the indication for Methotrexate?
To maintain remission of Chron’s Disease
What is the indication for Infliximab?
Moderate to severe IBD
