Pharmacologic Treatment

Pharmacological treatment

IBD can affect people in a variety of ways, whether this be the type of IBD (i.e., Crohn’s disease vs. ulcerative colitis), the location/extent of inflammation, or IBD-related complications (e.g., abscesses, fistulae, malnutrition). The medications used to treat IBD are similarly varied and are used according to your unique case. The main classes of drugs used in IBD are:


  • Aminosalicylates
  • Immunosuppressants
  • Antibiotics
  • Corticosteroids
  • Biologics
Aminosalicylates (5-ASAs)

5-ASAs are used for both reducing and maintaining remission of IBD. They come in different formulations, which can be administered orally, or rectally via suppository/enema. 5-ASAs work by reducing inflammation in the intestinal tissues, allowing the bowel to heal.


5-ASAs are common to induce remission mild to moderate ulcerative colitis and as a maintenance treatment to prevent flare-ups. These medications are less commonly used in Crohn’s disease but may be used in cases of mild disease activity.


Immunosuppressants reduce inflammation by suppressing the body’s immune system. Common immunosuppressants include methotrexate and thiopurines such as azathioprine and 6-mercaptopurine.


Depending on the drug/patient diagnosis, immunosuppressants can used to induce and/or maintain remission. These drugs may also be combined with biologics such as infliximab and adalimumab to increase their effectiveness.


Antibiotics work by decreasing bacterial concentrations in the gut. Antibiotics target specific inflammation-causing bacteria, which changes the composition of the gut microbiome so there is a better ratio of good bacteria to bad bacteria. Antibiotics are also useful for reducing inflammatory bacteria associated with IBD complications such as abscesses (i.e., inflamed pus-filled cavities) and fistulae (i.e., abnormal connections/channels between organs/tissues).


Antibiotics may be used to help with inducing and maintaining remission, as well as for preventing infection after surgery.


Corticosteroids (e.g., prednisone, hydrocortisone, budesonide) work by suppressing the immune system and reducing inflammation.


Corticosteroids are used for controlling symptoms and inducing remission. Because there are significant adverse effects with long-term use (e.g., bone density loss, hormonal/mood changes), steroids are not recommended as a maintenance medication –the goal of treatment is to maintain remission without the need for ongoing steroid use.


Biologics are different to other (i.e., chemical) IBD treatments as theyare made using living organisms. These living cells produce proteins which are then harvested to create the drug. Biologics use a variety of different mechanisms to reduce inflammation in the gut.


Biologics are usually reserved for moderate to severe cases of IBD where other treatments have failed. These drugs can be used for both inducing remission, and as a maintenance medication, to prevent flareups.

Therapeutic drug monitoring

Therapeutic drug monitoring (TDM) involves measuring the amount of a drug that is present in the body at a given time. There are several reasons why this can be useful for treating IBD. For a given drug to work as intended, there needs to be enough of it available in the body. TDM can help with this, as it allows doctors to examine whether the concentration of a drug is optimal, or if adjustment is necessary (e.g., increased/decreased dose, or more/less frequent dosage). Maintaining optimal drug levels increases the likelihood of patient well-being and makes it less likely a person will experience the undesirable effects of getting too much of a drug (e.g., side effects). This can be challenging without TDM, as the time it takes for a drug to be absorbed, distributed, metabolised and excreted can vary from person to person.

Some drugs, such as infliximab, are typically dosed every 8 weeks. If the drug level falls too low towards the end of this cycle, there is a greater likelihood of symptoms returning. In this scenario, your doctor might request a blood test be taken right before you get your next dose, when drug levels are at their lowest to see if there is still enough of the drug available to be effective. In the case of biologic drugs (e.g., infliximab, adalimumab), there is also the possibility that they may lose effectiveness over time due to the body producing anti-drug antibodies (ADAs). TDM also allows doctors to monitor the level of ADAs and adjust treatment accordingly. This might mean introducing or increasing the dosage of an immunomodulator drug (e.g., azathioprine, 6-mercaptopurine) taken in combination with the biologic drug to prevent the development of ADAs. TDM is currently available for Infliximab (and biosimilars Inflectra, Renflexis), Adalimumab, and thiopurines (e.g., azathioprine, 6-mercaptopurine), and is expected to become available for other biologic drugs (e.g., vedolizumab, golimumab, ustekinumab).

Issues with pharmacologic treatment

Pharmacological treatments can be a powerful tool for reducing symptoms and improving quality of life, however, this largely relies on them being used as intended (e.g., not missing doses, taking the correct dose). Patients that do not properly adhere to their medication regimen are likely to experience greater disease severity and are more likely to experience a relapse of symptoms. Some common challenges are described below with advice on how to deal with them.



The Australian government offers several schemes to offset the cost of medical treatment. These include the health care card and the Medicare Safety Net. For information regarding your eligibility for these schemes go to:



Forgetting to take medication is a common issue among IBD patients. This can involve simply missing a dose or forgetting to obtain/fill a prescription before the current supply runs out. Taking steps to avoid this is one of the most important things you can do for your wellbeing. Using cues/reminders, pill-boxes, or a calendar/checklist can help with this. You may also wish to discuss your medication regimen with your partner or family, as they can help you stay on top of your dose schedule.

Misunderstanding medication regimen/regimen complexity

IBD patients are often on more than one medication and the medication type/dosages often change in response to the current level of disease activity. It is important to discuss your current medication regimen with your doctor to ensure you are taking the correct medications at the right dosage and times.

Beliefs: scepticism, indifference, ambivalence

People have different views towards the necessity of their medications and their concerns about taking them. If you have concerns around taking your prescribed medications, it is essential that you discuss these with your doctor. Abruptly stopping or reducing some medications can have a significant impact on your health. An open dialogue can reveal the reasons/benefits of taking a medication, as well as other potential treatment options.



IBD can be a significant source of stress in one’s life, whether it be the immediate physical symptoms of active disease, or the disruption it can cause in your daily living (e.g., work, school). Stress is known to reduce adherence to medications among IBD patients. Social support (e.g., partner, friends, family) and exercise can help reduce this. If stress becomes unmanageable it is important to seek help from a mental health professional.


Concerns about adverse effects

As with countless other medications, the medicines used in IBD treatment can carry a risk of adverse effects. Concern about adverse effects is valid and justifiable –you should not be apprehensive or feel guilty about raising these concerns. Some people with IBD may skip or reduce dosages of their medication due to the fear or belief that they may cause harm. This is not advised, as reducing or abruptly stopping some medications can cause significant health issues. Ultimately, your doctor has prescribed your medications because their benefits outweigh their risks. Regardless, different drugs have different risks/effects and any concerns you have should be raised with your doctor so that you can find an effective treatment that you are comfortable with.


Beyond IBD drugs – other medications

Aside from your regular IBD drug treatments, you may also find other medications useful for managing symptoms. Other medications to consider include:

  • Anti-diarrheal drugs such as Imodium and Lomotil can be used to slow down intestinal contractions, reducing diarrhea
  • Laxatives can be used to reduce relieve constipation. These come in various forms:
    • Osmotic laxatives work by drawing more water into the large bowel
    • Bulk formers absorb water resulting in softer stool and easier passage through the bowels
    • Stimulant laxatives work by stimulating the bowel into more regular contractions
  • Analgesic (i.e., pain relieving) drugs such as paracetamol can be used to relieve mild pain. Non-steroidal anti-inflammatories (e.g., Ibuprofen, aspirin, naproxen) may exacerbate symptoms and should be discussed with your doctor