Pharmacotherapy of Inflammatory Bowel Disease Flashcards
What is Inflammatory Bowel Disease?
Inflammatory bowel disease is a spectrum of remitting and relapsing chronic, inflammatory intestinal conditions
What are the two types of IBD?
CRohn’s and UC
What is Crohn’s?
TRansmural inflammation of any part of the GIT but most commonly in the area adjacent to the ileocecal valve
What is UC?
Characterized by confluent mucosal inflammation of the colon, the anal verge and extending for a variable extend
What are the different types of UC based on their location?
Proctitis
Left-sided colitis
Pancolitis
What do the extra-intestinal manifestations of Crohn involve?
Joints
Skin
Eyes
What are the objectives of the treatment?
Scute treatment of illness
Induction and maintenance of clinical remission and improvement of quality of life
Cellular level: induction of mucosal healing
Reduced risk of surgical complication
Reduced rates of hospitalization
What are possible surgical complications regarding IBD?
Fistula, colorectal cancer, Intestinal obstruction
Which drugs are used for induction of remission?
Sulfasalazine, Mesalamine
Steroids (glucocorticoids)
In the case of steroid refractory (steroid resistance) which drugs are given?
Azathioprine or 6-Mercapto-purine
Methotrexate
anti-TNFα
What is the maintenance of remission medications?
Azathioprine or 6-Mercapto-purine
Methotrexate with anti-TNFα
In which kind of IBD cases is Methotrexate given as maintenance of remission?
Crohn’s
What are other biological therapies?
Anti-integrins
Anti-IL-12/23 (Ustekinumab)
Inhibitors of new targets (Jak kinase and S1 receptors)
What are the examples of 5-aminosalicylates?
Mesalamine
Sulfasalazine
Olsalazine
Balsalazide
Which kind of steroids are used as treatment of IBD?
Glucocorticoids
What are the examples of disease-modifying agents?
Methotrexate
Azathioprine/6 - Mercatopurine
What are other treatment options for IBD?
Fecal microbiota transfer
Probiotics
Balance of nutrition
Surgery followed by medication
What are the cellular and molecular aspects of IBD?
Interaction of bacteria and immune cells in the intestine
APCs activate T lymphocyte helper cells through the HLA2-TCR bond
Pro-inflammatory TH1 lymphocytes activate macrophages (which cause inflammation, modification, and proliferation)
Recruitment of monocytes to the inflammatory patches
What causes the destruction of the barrier of epithelia to allow for bacterial components to enter the intestinal lamina propria?
Dysbiosis - dysbacteriosis –> disruption of the microbiota
What is the other name of Mesalamine?
Mesalazine
Which 5-ASA drug has antibiotic activity?
Sulfasalazine
What are 5-ASA the first line treatment for?
Mild to moderate ulcerative colitis
How can 5-ASA be used?
With or without glucocorticoids
Where are the anti-inflammatory effects of 5-ASA targetted?
Targetted topically to the mucosa, with limited effects on deeper inflammation –> more used in UC
What is the MOA of 5-ASA?
Not identified clearly:
1. Inhibition of the production of IL-1 and TNF-a
2. Inhibition of the production of cyclooxygenase-lipoxygenase pathway,
3. Scavenging of free radicals and oxidants
4. Activation of PPAR-γ or inhibition of NF-kB
What is NF-kB?
A transcription factor pivotal to the production of inflammatory mediators
What is the cyclooxygenase-lipoxygenase pathway function?
What is their effect?
To convert arachidonic acid into:
ROS
PGE2
IL-6
IL-1
TNF-a
These increase inflammation
Why do physicians give 5-ASAs even though they are not specific inhibitors?
They have results and they also have few side effects
What are the PK of 5-ASAs?
Well absorbed
Clinical effect usually occurs 1 week to 3 months
Mild states of IBD
What is the PK of Mesalamine?
Directly active
Large part eliminated in the stool
Catabolysed by acetylation and hydroxylation in the liver and eliminated in the urine
What are the PK of Sulfasalazine?
Sulfasalazine is broken down by bacteria in the intestine to sulfapyridine and 5-ASA
What are the PK of Olsalazine?
Bacterial flora breaks it into two 5-ASAs
WHat are the PK of Balsalazide?
Broken by the colon bacteria
What is the site of action for Mesalamine?
Mesalamine has a delayed release or pH-dependent release –> only broken down when it reaches the colon
Sites of action: duodenum, ileum, jejunum and colon
What is the site of action of Sulfasalazine, Balsalazide, Olsalazine?
Colon
What are the side effects of Mesalazine?
Generally well tolerated:
1. Headache, dyspepsia, skin rash, flatulence, hepatitis
2. Nephrotoxicity (rare but serious)
3. Association with interstitial nephritis
What are the side effects of Sulfasalazine?
- Headache, nausea, and fatigue
- Alergic reaction (rash, fever, hepatitis, pneumonitis, hemolytic anemia and bone marrow suppression)
- Reversible oligospermia
- Inhibitions of intestinal folate absorption
What % of patients on Sulfasalazine present with side effects?
10 to 45%
What causes the allergic reaction in Sulfasalazine?
Sulfa molecule
What are the side effects of Olsalazine and Balsalazide?
Diarrhea (10 to 20% of patients)
What are glucocorticoids first-line therapy for?
Severe UC
What are the PK of glucocorticoids?
Good absorption / excellent bioavailability
Oral, IV, rectal
How can glucocorticoids be given orally/rectally?
Suppositories or enema
What are examples of glucocorticoids?
Budesonide
Prednisolone
Methylprednisolone
Hydrocortisone
What are glucocorticoids useful for?
Induction of remission for both UC/CD
NOT during maintenance of remission
What are the 3 categories of glucocorticoid patients?
Glucocorticoid-responsive patients
Glucocorticoid-dependent patients
Glucocorticoid-unresponsive patients
What are glucocorticoid-responsive patients?
Patients that improve and remain in remission as the steroids are tapered and then discontinued
What are glucocorticoid - dependent patients?
Patients that respond to glucocorticoids but then there is a relapse of symptoms if tapered opr discontinued
What are glucocorticoid-unresponsive patients?
Patients who do not improve even with prolonged high-dose steroids
What is the MOA of steroids?
The steroid present is blood bond to CBG, binds in free form
The main receptor is an intracellular steroid receptor that is associated with heat steroid protein HSP90
Receptor complex H-receptor is formed and HSP90 is released
The H/R complex enters the nucleus as a dimer, binds to Glucocorticoid-response-elements on the gene, and regulates transcription factor
Protein expression/ modualtion decreases