Dalteparin and Lecanemab-Irmb Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Lecanemab-Irmb Injection
Dalteparin
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.
What happens
An increased risk of amyloid related imaging abnormalities (ARIA), or intracerebral hemorrhage
Interaction Deep Dive
Concomitant use of lecanemab-irmb with an anticoagulant agent may increase the risk of amyloid related imaging abnormalities (ARIA) or intracerebral hemorrhage. Exert caution when considering the use of lecanemab-irmb in patients with factors that indicate an increased risk for intracerebral hemorrhage and in particular for patients who need to be on anticoagulant therapy, or patients with findings on MRI that are suggestive of cerebral amyloid angiopathy. Exert additional caution with concomitant use of lecanemab-irmb and antithrombotics, as it may increase the risk of ARIA or intracerebral hemorrhage, because amyloid related imaging abnormalities with edema (ARIA-E) can cause focal neurologic deficits that can mimic an ischemic stroke. Patients taking lecanemab-irmb with an anticoagulant alone or combined with an antiplatelet medication or aspirin had an incidence of intracerebral hemorrhage of 2.5% (2/79 patients), compared to none in patients who received placebo2. Due to limited evidence regarding safety of coadministration, patients on warfarin, vitamin K antagonists, direct oral anticoagulants, or heparin should be excluded from lecanemab-irmb therapy until more information is available. If patients receiving lecanemab-irmb develop conditions that require anticoagulant therapy, discontinue lecanemab-irmb and reinstate if/when anticoagulation is no longer necessary 1.
Why it happens (mechanism)
Additive effects on bleeding
Literature reports
1 report — tap to read
a) Patients taking lecanemab-irmb with an anticoagulant alone or combined with an antiplatelet medication or aspirin had an incidence of intracerebral hemorrhage of 2.5% (2/79 patients), compared to none in patients who received placebo 2.
Common questions
Can I take Dalteparin and Lecanemab-Irmb Injection together?
An increased risk of amyloid related imaging abnormalities (ARIA), or intracerebral hemorrhage Always confirm with your pharmacist or prescriber before making any change.
How serious is the Dalteparin and Lecanemab-Irmb 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 strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Dalteparin or Lecanemab-Irmb 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)
Keep reading about Lecanemab-Irmb Injection
Keep reading about Dalteparin
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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.
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