Continued 5ASA Use After Initiation of Anti-TNF or Immunomodulator Confers No Benefit in IBD

A Population-based Study

Charles N. Bernstein; Aruni Tenakoon; Harminder Singh; Laura E. Targownik


Aliment Pharmacol Ther. 2021;54(6):814-832. 

In This Article

Abstract and Introduction


Background: With the advent of biological therapy in IBD, it is uncertain to what extent 5aminosalicylates (5ASA) are used.

Aims: To explore whether or not 5ASA is continued once biological or immunomodulator therapy is initiated, and the outcomes in those who continued the 5ASAs.

Methods: We conducted a retrospective cohort study using the population-based University of Manitoba IBD Epidemiologic Database which includes prescription drug dispensation from 1996 through 2018. We assessed outcomes among 5ASA users who continued versus discontinued 5ASA after initiation of anti-TNF therapy or immunomodulators.

Results: In all, 8379 (77%) of persons with IBD received at least one 5ASA dispensation (85% of ulcerative colitis, UC and 68% of Crohn's disease, CD). There was a reduction in later years, particularly for CD. The most common pattern of 5ASA use was intermittent at 65.1% (stopping and restarting use) versus one-time (4.1%), previous continuous (13.8%) and persistent (17%). Among the total IBD population use was 59% oral, 3% rectal and 14% combination. Of all 5ASA starts, only 25% were continued longer than 20 months. After immunomodulator or anti-TNF initiation, there was no difference in either UC or CD for negative outcomes (hospitalisation, surgery, corticosteroid starts, colorectal cancers or drug-related adverse events) between those who continued 5ASA versus those who discontinued.

Conclusions: 5ASA remains commonly prescribed in UC and CD. Rates of persistent use in UC are low. Once an anti-TNF or immunomodulator is initiated, continuation of 5ASA seems to add no benefit.


5-aminosalicylic acid (5ASA) is still considered first-line therapy in the treatment of mild to moderate ulcerative colitis (UC).[1] The data are robust that persons with UC who are in remission on 5ASA are significantly more likely to remain in remission with continuation of 5ASA.[2] Histologic remission is achieved after induction in up to 45% of patients treated with topical 5ASA and 30% with oral formulations.[1] While 5ASA is an effective first-line therapy in UC,[3,4] it is not considered to be effective in Crohn's disease (CD).[5,6] Yet, it is common for patients with CD to be prescribed 5ASA.

5ASA offers a favourable safety profile compared to that of biologics and immunomodulators and is much cheaper than biological therapy. With the advent of biological and small molecule oral therapies, it is unclear as to how or even whether the use of 5ASA has evolved over the past several years. Furthermore, there is uncertainty as to whether the concomitant use of 5ASAs has incremental value in persons who are receiving immunomodulators or biological agents.

Therefore, we sought to perform an assessment of patterns and trends of 5ASA monotherapy and in combination with other agents, and to determine the impact of 5ASA use on the risk of adverse outcomes in persons with IBD. In a population-based assessment of 5ASA use since 1996 in Manitoba, we describe the patterns of use of 5ASA in persons with UC and in persons with CD. We assessed to what extent 5ASA is continued after anti-TNF or immunomodulator therapy is initiated and if outcomes are altered by continuing or stopping the 5ASA. We assessed the incidence of colorectal cancer and some other important complications evident in users of anti-TNF or immunomodulator therapy by whether or not 5ASA use was continued.