IBD Flashcards
List 3 different symptoms of IBD
- abdominal pain and cramping
- diarrhoea
- blood in stool
- unintended weight loss
Can diet and chronic stress cause IBD?
No. They can only aggravate the condition
List 2 main causes of IBD
- autoimmune
- hereditary
For which condition is cigarette smoking particularly bad?
Crohn’s
Briefly explain the immune response that can cause IBD.
An impaired barrier allows microbial products to enter the cell which activates an immune response. Regulatory mechanisms fail, leading to chronic inflammation due to an imbalance of pro and anti inflammatory markers
Name an anti-inflammatory regulatory mechanism
Regulatory T cells
Which drug class is a risk factor for IBD and should be substituted out?
NSAIDs
Name the drug that can be used for first line treatment of mild to moderate ulcerative colitis
5-asa’s. mesalamine / mesalizine
MOA of mesalamine?
Stops the production of leukotrienes
Are leukotrienes pro or anti inflammatory?
Pro
Patients with Crohn’s disease confined to the colon can be given which drug commonly used for ulcerative colitis?
Mesalamine
Explain the use of sulfasalazine as opposed to mesalamine
Mesalamine is given as an enema.
It can be conjugated to form sulfasalazine which has an azo bond. When given orally, the azo bond prevents absorption in the stomach and small intestine. The colonic bacteria cleaves the bond and activates the molecule
Mesalamine is also known as…
Mesalizine
Glucocorticoids are used for IBD when other treatments fail. Explain their MOA
They inhibit phospholipase A2, which consequently inhibits the production of pro-inflammatory molecules
Explain the longer term MOA of glucocorticoids
Can alter gene expression, resulting in more anti-inflammatory marker production and less pro-inflammatory markers
Cushing syndrome is an ADR of glucocorticoids. Give som examples of Sx
Puffy face, increased facial hair, insomnia, high BP, osteoporosis, etc
Corticosteroids can — remission but cannot — it.
Can induce remission but cannot maintain it
Give 2 examples of glucocorticoids and their dosage form for IBD
Prednisone (rectal)
Budesonide (slow release in colon)
What treatment option is there for severe IBD or steroid-dependent or steroid-resistant IBD?
Immunosuppressive agents
Mercaptopurine and azothioprine are examples of which class of drugs?
Immunosuppressive agents
Explain the MOA of mercaptopurine and azothioprine
Impairs purine synthesis which inhibits proliferation of fast replicating cells (immune cells)
Before starting immunosuppressive agents, which test should be done?
Need to test for TPMT (thiopurine methyltransferase) activity. Because some people have varying levels
Explain the action of TPMT enzyme
Converts mercaptopurine and azothioprine into their active forms
What TDM is required when using immunosuppressive agents?
Need to monitor circulating blood counts, because bone marrow can be suppressed.
List some ADRs of mercaptopurine use
Pancreatitis, nausea, vomiting, fever, etc
Which drug both induces and maintains remission in Crohn’s disease
Methotrexate
Why is methotrexate used at higher doses in Crohn’s than in rheumatoid arthritis?
Because of its unpredictable absorption in the intestine
Methotrexate MOA?
Inhibits DNA synthesis, causing cell death. It is an immunosuppressant
List 3-4 ADRs of methotrexate
Hepatotoxicity, leukopenia (low white blood cell count), predisposition to infections, teratogenic
Name a treatment option for severe ulcerative colitis in patients who are not responsive to glucocorticoids
Cyclosporine
Cyclosporine MOA?
Inhibits the activation of T cells by inhibiting calcineurin
What does the suffix -mab indicate?
Monoclonal antibodies
Explain the use of monoclonal antibodies in IBD
They are TNF-alpha antagonists. TNF is an inflammatory cytokine produced by macrophages
Which supplements can be used as supportive therapy for IBD?
Iron - if intestinal bleeding is present
Vitamin B12
Calcium and vitamin D
Explain the use of anticholinergics in IBD
Reduces abdominal cramps, pain and rectal urgency
Which IBD condition has an increased need for surgery?
Crohn’s
Implications of IBD surgery?
The affected part of the colon is removed. This reduces the absorption capacity of the colon
What is a characteristic feature of Crohn’s disease
Narrowing of the lumen
List some complications of Crohn’s disease
Bowel obstruction
Fistula
Malnutrition
Increased risk of colon cancer
Describe the characteristic features of ulcerative colitis
Inflammation causes ulcers to develop on lining of colon and rectum.
Tissue is eroded away and the lumen is very thin / narrow.
What would you see in a colonoscopy of ulcerative colitis?
Polyps (actually pseudopolyps that are not cancerous)
Name some complications of ulcerative colitis
Severe bleeding Perforated colon (life threatening) Dehydration due to diarrhoea Bone loss Increased risk of colon cancer
Drug used for acute attacks of IBD?
Glucocorticoids. Prednisolone or budesonide
Main drug used to maintain IBD remission?
Mesalamine
Drug reserved for severe IBD?
Infliximab
When are methotrexate and immunosuppressive agents like mercaptopurine used for IBD?
In severe cases or when steroid resistant / dependent
