Abatacept and Adalimumab: 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
Adalimumab
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 are strong medicines that calm down an overactive immune system. Abatacept (Orencia) and adalimumab (a TNF blocker) each work in a different spot, but they both turn down your body's defenses. When you take them together, your immune system can get turned down too far.
The main worry is serious infections. In studies, using them at the same time led to more infections without helping people any more than one drug alone. That is why doctors don't combine them. The good news is your care team knows about this, and they will pick the right single medicine for you and watch you closely.
Effect: Additive immunosuppression from combining abatacept (T-cell costimulation blocker) with the TNF antagonist adalimumab, increasing risk of serious infection with no added efficacy.
- Direction: Pharmacodynamic (not PK); neither agent is enzyme-metabolized, so this is not a CYP/transporter interaction.
- Evidence: Theoretical mechanism, but supported by controlled trials showing increased serious infection.
- Onset: Unspecified.
- Management: Concurrent use is not recommended. When transitioning from a TNF antagonist to abatacept, monitor for signs and symptoms of infection during the overlap/washout window.
What happens
An increased risk of infection
Interaction Deep Dive
Randomized controlled trials showed that giving abatacept together with tumor necrosis factor (TNF) antagonists raised the likelihood of serious infection while offering no further clinical benefit. Available data are inadequate to judge whether abatacept can be safely and effectively combined with anakinra or with biologic agents used for rheumatoid arthritis or psoriatic arthritis. For this reason, using these medications alongside abatacept is not advised. Patients moving from TNF antagonist treatment to abatacept should be watched for indications of infection1.
Why it happens (mechanism)
Unknown
How to manage this interaction
The key point: these two are generally not used together. Your care team will typically choose one biologic rather than combining abatacept with a TNF blocker like adalimumab, because the pair raises infection risk without extra benefit.
- Keep taking exactly what your prescriber has ordered, and do not stop or change either drug on your own.
- If you are switching from adalimumab to abatacept, expect your team to watch you closely for signs of infection during the changeover.
- Tell your doctor or pharmacist right away about fever, chills, cough, or any new infection symptoms.
- Ask your pharmacist to review your full medication list so no overlap slips through.
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 relative to etanercept used by itself. In a 1-year randomized trial (N=121) that was followed by an open-label long-term extension (LTE; n=80), rheumatoid arthritis patients who were already receiving etanercept 25 mg twice/week kept taking etanercept and were assigned at random to receive either abatacept 2 mg/kg IV on days 1, 15, and 30, and then every 4 weeks thereafter (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 about 10 mg/kg. At 6 months, the 2 mg/kg abatacept group demonstrated no meaningful 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; furthermore, the concomitant therapy offered no additional benefit 1.
Common questions
Can I take Abatacept and Adalimumab together?
Abatacept and adalimumab together over-suppress the immune system and raise the risk of serious infection with no added benefit, so they are not used together. Watch for infection signs when switching between them and let your care team guide the change. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abatacept and Adalimumab 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 Adalimumab interaction managed?
The key point: these two are generally not used together. Your care team will typically choose one biologic rather than combining abatacept with a TNF blocker like adalimumab, because the pair raises infection risk without extra benefit. Keep taking exactly what your prescriber has ordered, and do not stop or change either drug on your own. If you are switching from adalimumab to abatacept, expect… 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 Adalimumab 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 Adalimumab
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