PHARM; Lecture 19, 20 and 21 - Anti-emetic, IBD, Tx gastric and duodenal ulcers Flashcards
What are the 2 major forms of IBD?
UC and Crohn’s disease -> distinction incomplete in 10% of patients; 300,000 people in UK
Who does IBD affect?
Children, adolescents and adults
What are the risk factors for IBD?
Genetic = white european origin most susceptible; environmental factors = smoking (CD esp), diet, obesity and gut microbiome. NB: obesity is RF in CD but not UC
What is IBD?
Defective interaction between mucosal immune system and gut flora -> 10x more bacteria than host cells

What is the difference between CD and UC - type of AI disease, gut layers affected, regions of gut affected, inflamed area characteristics, abcesses/fissues/fistulas, surgery use?
NB: because inflammation is patchy in CD, surgery isn’t curative as it is difficult to extract each site in the GIT and it often reoccurs (unlike UC which doesn’t)

What is a fistula?
Abnormal/surgically made passage between hollow tubular organ and body surface/between 2 hollow tubes/organs
What are the clinical features of IBD?

What are the types of treatments used for IBD?

What are the general ideas about aminosalicylates for UC/CD?
UC = first in line for inducing/maintaining remission; CD = unsure effectiveness in active disease, may help to maintain surgically induced remission
What are some examples of aminosalicylates?
Mesalazine(!! and also called 5-ASA) and Olsalazine (more complex molecule) and are anti-inflammatory
What is the mechanism of anti-inflammatory action?
Inhibition of IL-1, TNF-a, Platelet activating factor; decreased Ab secretion and cell migration; non-specific cytokine inhibition; localised inhib of IR
What are the targets of aminosalicylates?
Target Th1 mechanisms (TNFa) but works better with UC (governed by Th2)
What are the pharmacokinetics of 5-ASA?
NO metabolism needed -> absorbed by small bowel and colon (olsalazine needs to be activated by colonic flora - so only absorbed in colon); 5-ASA is safe and good at maintaining remission
What is the relative efficacy between steroids, 5-ASA and olsalazine in IBD?
Olsalazine needs to be activated by colonic bacteria, so is absorbed there and only acts in colon; 5-ASA (topical) is more effective at inducing remission than topical steroids BUT combined topical 5-ASA and oral steroids are better at inducing remission than oral 5-ASA
What are the uses of glucocorticoids in UC?
In decline, can be used topically (enema) or iv if v. severe; BUT ASA is superior (evidence suggests)
What are the uses of glucocorticoids in CD?
Drug of choice to induce remission; likely to get side effects if continued use to maintain remission
What are glucocorticoids?
Prednisolone, fluticasone, budesonide -> powerful anti-inflammatory and immunosuppressive drugs -> activate GR which act as +/-ve transcription factors
How can you minimise the side effects of glucocorticoids?
Topical admin (fluid/foam enemas/suppositories); low dose in combination with other drug; use oral/topically admin drug with high hepatic first pass met (budesonide = less side effects than prednisolone) to minimise GC in systemic circulation
What are the different immunosuppressive agents used in IBD?
Azathioprine and 6-mercaptopurine (not in CD, some success in UC); methotrexate (some IBD); cyclosporin (in severe UC only)
What is azathioprine?
Immunosuppressive; maintain remission in CD with slow onset = 3-4 months treatment for clinical benefit; steroid-sparing, superior to placebo and budesonide
What is the pharmacokinetics of azathiprine and what is the mechanism of immunosuppression?
Activated by gut flora to 6-mecaptopurine -> purine antagonist, interfering with DNA synthesis and cell replication

What are the unwanted effects of azathioprine?
Nearly 10% of patients have to stop treatment -> associated with pancreatitis, bone marrow suppression, hepatotoxicity, increased risk of lymphoma and skin cancer
What are the main routes of metabolism of azathioprine?
- 3 -> 6-TGN produces beneficial active metabolites which can also cause myelosuppression;
- 6-MMP causes non-beneficial metabolites which are hepatotoxic;
- main metabolic route is the Xanthine oxidase pathway as metabolites are inert so won’t cause problems ->
- but if allopurinol (gout) taken inhibition of XO occurs, shunting AZA to other pathways

What is methotrexate?
Demonstrable effect in CD; folate antagonist reducing thymidine (and other purines) synthesis; not widely used in monotherapy (significant unwanted effects)


























