A new study has found no convincing evidence to suggest a causal relationship between nonsteroidal anti-inflammatory drug (NSAID) use and inflammatory bowel disease (IBD) exacerbations.
Rather, the study suggests that observed associations between IBD exacerbation and NSAID exposure may be explained by preexisting underlying risks for IBD flares, residual confounding, and reverse causality.
“We hope these study findings will aid providers in better directing IBD patients on their risk for IBD exacerbation with NSAID use,” write Shirley Cohen-Mekelburg, MD, with University of Michigan Medicine, Ann Arbor, and colleagues.
“This may guide therapy for both IBD and non-IBD related pain management, and the comfort of patients with IBD and the clinicians who treat them when considering NSAIDs as a non-opioid treatment option,” they add.
The study was published online in the American Journal of Gastroenterology.
Taking a second look
Patients with IBD (Crohn’s disease and ulcerative colitis) are prone to both inflammatory and noninflammatory pain, and there has been long-standing concern that NSAIDs may play a role in disease flare-ups.
To see whether a true association exists, Dr. Cohen-Mekelburg and colleagues conducted a series of studies that involved roughly 35,000 patients with IBD.
First, they created a propensity-matched cohort of 15,705 patients who had received NSAIDs and 19,326 who had not taken NSAIDs. Findings from a Cox proportional hazards model suggested a higher likelihood of IBD exacerbation in the group that had taken NSAIDs (hazard ratio, 1.24; 95% confidence interval, 1.16-1.33), after adjusting for age, gender, race, Charlson comorbidity index, smoking status, IBD type, and use of immunomodulator or biologic medications.
However, those who received NSAIDs were already at increased risk of experiencing a disease flare. And the prior event rate ratio for IBD exacerbation, as determined by dividing the adjusted HR after NSAID exposure by the adjusted HR for pre-NSAID exposure, was 0.95 (95% CI, 0.89-1.01).
The researchers used a self-controlled case series to verify their findings and to adjust for other immeasurable patient-level confounders. In this analysis, which involved 3,968 patients, the risk of IBD flare did not increase in the period from 2 weeks to 6 months after exposure to an NSAID.
The incidence of IBD exacerbations was higher in the 0- to 2-week transition period after an NSAID was prescribed, but it dropped after the 2-week “risk” window. This suggests that these short-term flares may be secondary to residual confounding related to reverse causality, rather than the NSAIDs themselves, the researchers say.
While NSAIDs represent the most common first-line analgesic, their use for patients with IBD is variable, in part due to the suspected risk of IBD exacerbation “despite inconclusive evidence of harm to date,” Dr. Cohen-Mekelburg and colleagues note.
They also note that about 36% of patients with IBD in their cohort received at least one NSAID prescription, and three-quarters of these patients did not experience an IBD exacerbation during an average of 5.9 years of follow-up.
Good study, reassuring data
“This is a good study trying to understand the potential sources of bias in associations,” Ashwin Ananthakrishnan, MD, MPH, with Massachusetts General Hospital and Harvard Medical School in Boston, who wasn’t involved in the study, told this news organization.
Overall, he said the study “provides reassurance that cautious, short-duration or low-dose use is likely well tolerated in most patients with IBD. But more work is needed to understand the impact of higher dose or more frequent use.”
Also weighing in, Adam Steinlauf, MD, with Mount Sinai Health System and Icahn School of Medicine at Mount Sinai in New York, noted that patients with IBD experience pain throughout the course of their disease, both intestinal and extraintestinal.
“Treating the underlying IBD is important, but medications used to treat joint pain and inflammation specifically are few,” said Dr. Steinlauf, who wasn’t involved in the new study.
“Sulfasalazine has been used with success, but it does not work in everyone, and many are allergic to the sulfa component, limiting its use. Narcotics are often reluctantly used for these issues as well. Medical marijuana has emerged on the scene to control both types of pain, but to date, there is inconclusive evidence that it significantly treats both pain and underlying inflammation,” Dr. Steinlauf pointed out.
NSAIDs, on the other hand, are “excellent” choices for treating joint pain and inflammation, but gastroenterologists often try to avoid these medications, given the fear of triggering flares of underlying IBD, Dr. Steinlauf told this news organization.
In his view, this new study is “important in that it quite elegantly challenges the notion that gastroenterologists should avoid NSAIDs in patients with IBD.”
Although more data are clearly needed, Dr. Steinlauf said this study “should give practitioners a bit more confidence in prescribing NSAIDs for their patients with IBD if absolutely necessary to control pain and inflammation and improve quality of life when other standard treatments fail.
“The association of NSAIDs with subsequent flares, of which we are all so well aware of and afraid of, may in fact be related more to our patients’ underlying risks for IBD and reverse causality rather than the NSAIDs themselves. Future studies should further clarify this notion,” Dr. Steinlauf said.
The study received no commercial funding. Dr. Cohen-Mekelburg, Dr. Ananthakrishnan, and Dr. Steinlauf have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
