Abatacept and Sarilumab: 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
Sarilumab
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.
Abatacept (Orencia) and sarilumab are both powerful medicines that calm down an overactive immune system. They work in different ways, but the concern is the same: when you take two immune-lowering biologics together, your body has a harder time fighting off germs. That can mean a higher chance of getting a serious infection, without giving you any extra benefit for your arthritis.
Because of this, using both at the same time generally isn't recommended. The good news is this is very manageable. Please don't stop or change anything on your own. Talk with your rheumatologist or pharmacist, who can pick the safest single therapy for you and watch closely for any signs of infection.
Effect: Additive immunosuppression increasing risk of serious infection with no added efficacy. Abatacept (T-cell costimulation modulator) plus sarilumab (IL-6 receptor antagonist) combines two biologic immunomodulators.
- Direction: Increased infection risk (additive pharmacodynamic effect).
- Mechanism: Unknown/additive; extrapolated from abatacept plus TNF antagonist trial data.
- Evidence: Theoretical for this specific pair; based on class experience with abatacept plus other biologic DMARDs.
- Onset: Unspecified.
- Management: Concurrent use not recommended. If transitioning between agents, monitor for signs/symptoms of infection.
Neither agent undergoes CYP-based metabolism, so this is a pharmacodynamic, not pharmacokinetic, interaction.
What happens
An increased risk of infection
Interaction Deep Dive
In controlled clinical trials, giving abatacept together with tumor necrosis factor (TNF) antagonists was shown to raise the likelihood of serious infection while offering no extra therapeutic benefit. The safety and efficacy of abatacept combined with anakinra, or with biologics indicated for rheumatoid arthritis or psoriatic arthritis, cannot be assessed because the available data are inadequate. For this reason, using these agents together is not advised. Patients who are switching from TNF antagonist therapy to abatacept should be watched for signs of infection1.
Why it happens (mechanism)
Unknown
How to manage this interaction
The main step here is avoiding the combination. Using abatacept together with sarilumab (or other biologic arthritis drugs) is generally not recommended because it raises infection risk without added benefit.
- Keep taking your medications exactly as prescribed, do not stop either one on your own.
- Let your care team know if you are on both, or if you are switching from one to the other.
- Your team may choose a single biologic rather than combining them.
- During any transition between these agents, expect closer monitoring for signs of infection (fever, chills, cough, sore throat, or wounds that won't heal).
Report any of those symptoms to your prescriber or pharmacist promptly.
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 efficacy but raised the risk of serious infection relative to etanercept by itself. In a 1-year randomized trial (N=121) followed by an open-label long-term extension (LTE; n=80), rheumatoid arthritis patients already receiving etanercept 25 mg twice/week continued that etanercept and were randomized to 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 phase, patients qualified for the LTE phase, at which point the abatacept dose was raised to roughly 10 mg/kg. At 6 months, the 2 mg/kg abatacept group demonstrated no significant improvement versus placebo 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 noted 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; furthermore, the combined therapy offered no additional benefit 1.
Common questions
Can I take Abatacept and Sarilumab together?
Combining abatacept and sarilumab is generally not recommended because it raises the risk of serious infection without added benefit; talk with your rheumatologist about using just one biologic and watch for signs of infection. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Abatacept and Sarilumab 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 Sarilumab interaction managed?
The main step here is avoiding the combination. Using abatacept together with sarilumab (or other biologic arthritis drugs) is generally not recommended because it raises infection risk without added benefit. Keep taking your medications exactly as prescribed, do not stop either one on your own. Let your care team know if you are on both, or if you are switching from one to the other. Your team ma… 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 Sarilumab 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 Sarilumab
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist