Abatacept and Certolizumab Pegol: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 16, 2026 · Source data updated Jul 16, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Abatacept
Certolizumab Pegol
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Both of these medicines calm down your immune system, just in different ways. Abatacept (Orencia) and certolizumab pegol are both biologic drugs used for conditions like rheumatoid arthritis. The problem is that using them together can quiet your immune system too much, which makes it easier to catch a serious infection. Studies also showed that combining them did not work any better than using one alone.
Because of this, doctors generally do not use these two together. The good news is your care team knows about this, and if you are switching from one to the other, they will keep a close eye out for any signs of infection like fever or feeling unwell.
Effect: Additive immunosuppression increasing risk of serious infection, with no added therapeutic benefit. Abatacept (T-cell costimulation modulator) plus certolizumab pegol (TNF-alpha antagonist) produces overlapping immunosuppressive pharmacodynamics; neither is a prodrug and the mechanism is otherwise unspecified.
- Direction: Increased combined immunosuppressive effect (PD interaction).
- Severity: Major. Evidence: Theoretical/derived from controlled trials of abatacept plus TNF antagonists.
- Management: Concurrent use is not recommended. When transitioning off TNF antagonist therapy to abatacept, monitor for signs of infection.
What happens
An increased risk of infection
Interaction Deep Dive
In controlled clinical studies, giving abatacept together with tumor necrosis factor (TNF) antagonists was shown to raise the likelihood of serious infection while offering no extra therapeutic benefit. Adequate data are lacking to assess the safety and effectiveness of combining abatacept with anakinra or with biologics indicated for rheumatoid arthritis or psoriatic arthritis. For this reason, using these drugs at the same time as abatacept is not advised. During the switch from TNF antagonist treatment to abatacept, patients should be watched for indications of infection1.
Why it happens (mechanism)
Unknown
How to manage this interaction
The main step here is avoiding the combination. Guidance says abatacept and TNF antagonists like certolizumab pegol should not be used together, because the added infection risk is not offset by any extra benefit.
- Keep taking your medications exactly as prescribed. Do not stop or change anything on your own.
- If your team is switching you from certolizumab to abatacept, they will watch you closely for signs of infection.
- Report fever, chills, cough, sores that won't heal, or feeling generally unwell to your care team promptly.
- Ask your pharmacist or prescriber before adding any new biologic or immune-affecting drug.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) Taking abatacept together with etanercept provided no extra efficacy but raised the risk of serious infection when compared with etanercept used on its own. In a 1-year randomized trial (N=121) followed by an open-label long-term extension (LTE; n=80), patients with rheumatoid arthritis who were already on etanercept 25 mg twice/week continued that etanercept and were randomized to receive either abatacept 2 mg/kg IV on days 1, 15, and 30, and then every 4 weeks (n=85) or placebo (n=36). After finishing the double-blind portion, patients could enter the LTE phase, at which point the abatacept dose was raised to approximately 10 mg/kg. At 6 months, the 2 mg/kg abatacept group demonstrated no significant improvement over the placebo group in modified American College of Rheumatology 20% (ACR20; 48.2% vs 30.6%) or ACR50 (25.9% vs 19.4%) response rates, though there was a significant difference in modified ACR70 rates (10.6% vs 0%). At 1 year, no significant differences in ACR20, 50, or 70 response rates were seen between the two groups. Serious adverse events occurred more often in the 2 mg/kg abatacept group (16.5%) at one year and in the 10 mg/kg abatacept group after 2 years of LTE (32.5%) than in the placebo group (2.8%). Serious infections at 1 year were reported in 3.5% of the 2 mg/kg abatacept group and 0% of the placebo group 2.
b) In controlled clinical trials involving adults with active rheumatoid arthritis who received abatacept together with a tumor necrosis factor (TNF) antagonist (n=204) versus TNF antagonist therapy alone (n=134), the rate of infection (63% vs 43%, respectively) and serious infection (4.4% vs 0.8%, respectively) was higher with the combined therapy; additionally, the combined therapy offered no added benefit 1.
Common questions
Can I take Abatacept and Certolizumab Pegol together?
Abatacept and certolizumab pegol are not recommended together because combining them raises the risk of serious infection without added benefit; talk with your prescriber before using both, and watch for signs of infection during any transition. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abatacept and Certolizumab Pegol interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Abatacept and Certolizumab Pegol interaction managed?
The main step here is avoiding the combination. Guidance says abatacept and TNF antagonists like certolizumab pegol should not be used together, because the added infection risk is not offset by any extra benefit. Keep taking your medications exactly as prescribed. Do not stop or change anything on your own. If your team is switching you from certolizumab to abatacept, they will watch you closely… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Abatacept or Certolizumab Pegol need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: ORENCIA(R) intravenous, subcutaneous injection, abatacept intravenous, subcutaneous injection. Bristol-Myers Squibb Company (per FDA), Princeton, NJ, 2020. DailyMed
- Weinblatt M, Schiff M, Goldman A, et al: Selective costimulation modulation using abatacept in patients with active rheumatoid arthritis while receiving etanercept: a randomised clinical trial. Ann Rheum Dis 2007; 66(2):228-234. PubMed
Keep reading about Abatacept
Keep reading about Certolizumab Pegol
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