Abatacept and Adalimumab Injection: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 16, 2026 · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Adalimumab Injection
Abatacept
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 to treat conditions like rheumatoid arthritis. Adalimumab (Humira and its biosimilars) blocks a protein called TNF, and abatacept (Orencia) quiets immune cells in a different way. Taken together, they don't work better, but they do raise your risk of serious infections because your body's defenses get turned down too far.
Because of this, doctors generally don't use these two at the same time. The good news is your care team knows about this and can plan the safest option for you. If you're switching from one to the other, they'll watch closely for any signs of infection like fever, chills, or a cough that won't quit.
Effect: Additive immunosuppression increasing the risk of serious infection, with no added therapeutic benefit. Both agents are biologics (neither is a prodrug); this is a pharmacodynamic, not pharmacokinetic, interaction.
- Direction: Increased infection risk from combined TNF-alpha antagonism (adalimumab) plus T-cell costimulation blockade (abatacept).
- Evidence: Controlled trials for the abatacept + TNF antagonist class; mechanism of the risk itself is theoretical/unknown magnitude.
- Onset: Unspecified.
- Management: Concurrent use not recommended. When transitioning off adalimumab to abatacept, monitor for signs and symptoms 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 added benefit. Data are inadequate to judge the safety and efficacy of combining abatacept with anakinra or with biologic agents used for rheumatoid arthritis or psoriatic arthritis, so co-administration with such agents is not advised. During a switch from TNF antagonist therapy to abatacept, patients should be watched for indications of infection1.
Why it happens (mechanism)
Unknown
How to manage this interaction
The main guidance here is that these two are not used together. Combining adalimumab and abatacept raises infection risk without improving results, so your care team will typically pick one biologic rather than both.
- Keep taking your medications exactly as prescribed. Do not start, stop, or change either one on your own.
- If your team is switching you from adalimumab to abatacept, they will monitor you for signs of infection during the transition.
- Report fever, chills, a persistent cough, sore throat, or any new sign of infection to your prescriber or pharmacist promptly.
- Ask your pharmacist to confirm your current biologic plan if you are ever prescribed both.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) Taking abatacept together with etanercept produced no extra benefit but did raise the risk of serious infection when compared with etanercept used on its own. 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 continued that etanercept and were randomized to receive either abatacept 2 mg/kg IV on days 1, 15, and 30 and 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 did not show a 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 a significant difference was seen in modified ACR70 rates (10.6% vs 0%). At 1 year, no significant differences were found in ACR20, 50, or 70 response rates 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 following 2 years of LTE (32.5%) than in the placebo group (2.8%). At 1 year, serious infections 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 of serious infection (4.4% vs 0.8%, respectively) was higher with the combined therapy; moreover, the concomitant therapy offered no additional benefit 1.
Common questions
Can I take Abatacept and Adalimumab Injection together?
Adalimumab and abatacept are generally not used together because the combination raises infection risk without added benefit; your care team will usually choose one and watch for infection during any switch. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abatacept and Adalimumab Injection 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 Injection interaction managed?
The main guidance here is that these two are not used together. Combining adalimumab and abatacept raises infection risk without improving results, so your care team will typically pick one biologic rather than both. Keep taking your medications exactly as prescribed. Do not start, stop, or change either one on your own. If your team is switching you from adalimumab to abatacept, they will monitor… 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 Injection 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 Adalimumab Injection
Keep reading about Abatacept
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