IBD Flashcards
What is comprised in IBD
UC: mucosal inflammatory condition confined to rectum and colon
Crohn’s: transmural inflammation of GI tract, mouth to anus
What causes IBD
Combo of infectious, genetic, environmental, and immunologic
Pharm Tx for IBD involves
anti-inflammatories
1. Aminosalicylates (Sulfasalazine, Mesalamine)
2. Corticosteroids (prednisone, budesonide)
(Also Tx with abx, immunosuppressives, biologics, and anti-integrins)
What are Sx of UC
rectal bleeding abd ttp Continuous distribution rectal involvement crypt abscesses
What are Sx of Crohn’s
Fever, malaise rectal bleeding abd pain abd mass fistulas aphthous ulcers discontinuous distribution ileal involvement strictures transmural granulomas linear clefts cobblestoning
Drugs that are less effective but with fewer ADE
Budesonide
Topical steroids
Antibiotics
5-aminosalicylates
Agents that are most effective but with a lot of ADE
Natalizumab
Cyclosporine
TNF antagonists
IV corticosteroids
What happens to aminosalicylates in the body
Sulfasalazine: converted to mesalamine in the colon
Asacol: Release is delayed until terminal ileum and cecum, then released as a bolus in right colon
What constitutes mild (low risk) Crohn’s
No/Mild Sx Nl/mils elevation of CRP Diagnosed 30+ Limited distribution No prior resections No strictures
How do you treat mild, low risk crohn’s
Budesonide to induce remission
What are the Aminosalicylates (5-ASA)
Azo compounds: Sulfasalazine, Olsalazine, Balsalazide
Mesalamine
What is the significance of Azo compounds
The structure reduces absorption from small intestine
In the terminal ileum and colon, bacteria cleave the azo bond and release active 5-ASA
What are the formulations of Mesalamine
Pentasa: timed release microgranules throughout small intestine
Asacol/Apriso: Coating dissolves at pH 6-7; distal ileum and proximal colon
Lialda: Dissolves in pH of colon. Slow release throughout colon
Rowasa: enema
Canasa: Suppository
What is the site of action of the IBD drugs
Jejunum: Pentasa
Ileum: Asacol, Lialda
Proximal colon: Sulfasalazine, Balsalazide
Rectum: Rowasa, Canasa
What is the PK of IBD drugs
Absorption of 5-ASA from colon is very low
Absorbed 5-ASA undergoes N-Acetylation in the gut and liver and is converted to a metabolite that is not anti-inflammatory
That metabolite is excreted by kidneys
What is the MOA of 5-ASA
Modulates inflammatory mediators derived from COX and LOX pathways
Interferes with production of inflammatory cytokines (NF-Kb)
Inhibit cell fxn of NK cells, lymphocytes, macrophages
Scavenge reactive oxygen metabolites
How does 5-ASA work in UC and Crohn’s
UC: Induce and maintain remission
Crohn’s: efficacy unproven, used mainly for mild-mod involving colon or distal ileum
What is first lint Tx for mild-mod UC
5-ASA!!!
Efficacy of 5-ASA depends on
achieving high drug concentration at site of active disease
- Rowasa and Canasa good for dz confined to rectum or distal colon
- azo compounds and mesalamine for dz in proximal colon
- pentasa, asacol, lialda for dz involving small bowel
What are ADE of Sulfasalazine
nausea vomiting HA rash hepatotoxicity, nephritis -monitor folate, CBC, LFT, SrCr, BUN *Has more ADE than others bc it is a fast acetylator
What are ADE of Olsalazine
secretory diarrhea
-monitor oligospermia (reverses on drug d/c)