Inflammatory bowel disease Flashcards
What is inflammatory bowel disease?
Refers to 2 chronic diseases that cause inflammation of the intestine: Ulcerative Colitis + Crohn’s disease
What is Crohn’s disease?
Chronic inflammatory bowel disease (IBD) that can affect any area of the gastrointestinal tract, from the mouth to the anus
Cause is unknown
Periods of exacerbations (inflammation) + remissions
Inflammation is across the whole wall of GI tract
Fissuring ulcers form (contents can leak out)
Damage caused by inflammation leads to submucosal fibrosis (body trying to repair)
Dense infiltration of lymphocytes + macrophages
What is Ulcerative Colitis?
Inflammation affects mucosal (inner) layer of the colon + rectum
Cause ulcers
Loss of goblet cells (secretes mucus)
Infiltration of inflammatory cells into mucosa
Unknown cause
What are the symptoms of Crohn’s?
Diarrhoea - impaired absorption
Pain
Narrowing of the gut lumen leading to strictures + bowel obstruction
Abscess formation
Fistulization to skin + internal organs
What are strictures?
Inflammation leads to scar tissue formation
Narrowing of lumen + obstruction
Risk of rupture
Pain, cramping, bloating
What are fistulae?
Inflammation leads to ulcers
Ulcers develop into tunnels
Between areas of GIT
or between organs
or to skin (anal fistulae)
Whata are the consequences of Crohn’s disease?
Weight loss
Macronutrient deficiencies
Micronutrient deficiencies (minerals, calcium, iron)
Fatigue
Protein-energy malnutrition in 20-80% of patients
What are the symptoms of ulcerative colitis?
Severe diarrhoea - changes in electrolytes
Blood loss
Loss of peristaltic function leading to rigid colonic tube
Toxic megacolon, perforation + sepsis
Where can extra-intestinal inflammation occur?
Joints, eyes, skin, mouth + liver
Forms of IBD (inflammatory bowel disease)
Risk of colon cancer (especially in u.colitis)
Treatment of Ulcerative Colitis
Drugs to reduce inflammatory response
5-aminosalicylate
Steroids (corticocosteroids)
Immunosuppressants
Function of 5-aminosalicylate
Inhibits leukotriene + prostanoid synthesis
Scavenge free radicals (prevent them damaging cells) + decrease neutrophil chemotaxis (movement of neutrophil to site of infection) - effects on PPARy receptor
Sulfasalazine metabolised to mesalazine
Absorbed in small intestine but doesn’t reach colon
Function of Corticosteroids
Anti-inflammatory, immunosuppressive actions
e. g. oral prednisolone
e. g. budesonide - poorly absorbed so fewer systemic side effects
Used to induce remission
Enemas used for more distal/rectal inflammation e.g. predfoam
Function of Immunosuppressants
Aazathioprine + methotrexate inhibit purine synthesis + DNA synthesis
Reduce inflammatory cell proliferation
Azathioprine is converted to mercaptopurine (purine derivative) - inhibits purine synthesis
Cyclosporine inhibits InterLeukin-2 induced gene expression
- used in refractory disease
Describe TPMT activity
One way merceptopurine is metabolised is by Thiopurine methyltransferase
Some patients have low TPMT
Some patients have no TPMT (risk of drug-induced bone marrow toxicity)
Some patients have high TPMT (risk of mercaptopurine resistance)
What is TNF-alpha
Tumour necrosis factor alpha or TNFα is a cytokine. Cytokines are substances released by the body during inflammation.
Function of anti-TNFalpha therapy
‘manufactured’ monoclonal antibody binds to TNFalpha + prevent from causing inflammation
Neutralises inflammatory cytokine TNF-alpha
- associated w/ TB risk (antibodies are peptides which will be broken down if given orally)
Infliximab = infusion
Adalimumab = injection
What is the nutrition therapy in Crohn’s?
Basic (elemental feeds) nutrition - can induce remission
Reduce steroid use in severe Crohn’s
Use parenteral support
Small bowel removal - shortened bowel
- reduce absorption
- require nutritional support
Probiotics
Ulcerative colitis is caused by the upset of colonic bacteria
Treatment options to induce remission in Crohn’s
Monotherapy
Add-on treatment
Biological therapy/in severe active Crohn’s
Drugs used in monotherapy in Crohn’s
Using a conventional glucocorticosteroid
- prednisolone
- methylprednisolone
- intravenous hydrocortisone
Alternative = budesonide/5-ASA
Drugs used in add-on therapy in Crohn’s
First line = azathioprine or mercaptopurine to a conventional glucocorticosteroid or budesonide to induce remission of Crohn’s disease
Second line = Methotrexate
Drugs used in biological therapy in Crohn’s
Infliximab/adalimumab
Counselling points on oral steroids
Taken once a day in the morning after food
Avoid contact w/ people that have shingles, chickenpox or measles
Carry steroid treatment card if taking oral corticosteroids for > 3 weeks
Could have mood/behavioural changes
Cannot stop abruptly
Lifestyle recommendations to minimise side effects include:
- adequate dietary intake
- good nutrition
- maintain normal body weight
- smoking cessation
- moderate alcohol consumption
- physical exercise
Counselling points on 5-ASA
Long-term effects of turnover of cells
Increased risk of bleeding, bruising, sore throat, fever, malaise (should be reported)
Enteric-coated tablets should be swallowed whole
Laxatives must be taken at least 2 hours before or after taking EC tablets
Sulfasalazine may colour tears yellow + urine orange + contact lenses to change colour
Counselling points on Azathioprine + Mercaptopurine
Test TMPT levels before therapy
Seek medical advice if they develop:
- sore throat
- nausea
- vomiting
- jaundice
- pancreatitis (abdominal pain)
