Emicizumab
- Article last reviewed 17 August 2026
- 10 mins read
What is this medication for?
Emicizumab (also known as Hemlibra®) is a monoclonal antibody (a man-made protein that attaches to a target in the body).
Emicizumab is used regularly to prevent or reduce the frequency of bleeding episodes in adults and children with haemophilia A, with or without factor VIII inhibitors. Haemophilia A is an inherited bleeding disorder resulting in absent or reduced levels of factor VIII. By replacing factor VIII, the factor VIII levels in the blood are increased, helping to temporarily correct the clotting deficiency to prevent or control bleeding.
However, some people with Haemophilia A develop inhibitors (antibodies against factor VIII), resulting in the replacement factor VIII becoming less effective. Emicizumab works differently from recombinant factor VIII, so it is still effective even when inhibitors are present.
This medication is for regular preventive treatment for haemophilia A only. It is not to be used to treat a bleeding episode.
How should I take or use this medication?
- Emicizumab is given by injection under the skin (subcutaneously).
- It is important for Emicizumab to be injected regularly as prescribed to ensure a stable level in the blood at all times to have a better chance of preventing bleeds.
- Your healthcare professional (i.e doctor or nurse) will train you on how to prepare and inject this medication before you could inject yourself or administer the injection for your child at home.
What should I do if I forget to take or use this medication?
- Emicizumab should be used regularly as per the treatment schedule agreed with your healthcare professional. If you miss your dose at the usual time, inject the next dose as soon as you remember as there is a risk of bleeding with missed doses.
- Monitor closely for any signs and symptoms of bleeding and contact your healthcare professional for advice.
What precautions should I take when taking or using this medication?
Inform your healthcare professional if:
- You are allergic to this medication or any of the other ingredients of this medication.
- You are taking non-steroidal anti inflammatory drugs (NSAIDs) such as Ibuprofen or blood thinners such as Aspirin as they may increase your risk of bleeding
- You are taking any other medications, including supplements, traditional medications and herbal remedies.
- You are pregnant, planning to become pregnant, or breastfeeding.
- Women of childbearing potential receiving emicizumab should use effective contraception (birth control) during, and for at least 6 months after stopping the medication.
- You have any dental treatments or surgical procedures planned.
IMPORTANT:
Emicizumab increases the ability of your blood to clot and there may be serious and life- threatening side effects when activated prothrombin complex concentrate (aPCC; FEIBA®) is used for breakthrough bleeds while on Emicizumab:
Damage of very small blood vessels with formation of blood clots within these vessels (thrombotic microangiopathy).
Signs include confusion, weakness, swelling of arms and legs, yellowing of skin and eyes, abdominal or back pain, feeling sick (nausea), being sick (vomiting) or urinating less.
Thromboembolism (blood clots):
Signs of abnormal blood clots (thrombosis): pain, swelling, warmth or redness in the leg or arm; sudden chest pain; shortness of breath; or coughing up blood.
If you experience any of these symptoms, you should stop your medication and proceed to the A&E department to seek immediate medical attention.
What are some common side effects of this medication?
This medication is generally well tolerated. Some possible side effects include:
- Injection site reactions such as pain, swelling, or redness.
- Apply a cool compress over the affected area for relief.
- Make sure you rotate the injection site with each injection
- Headache, dizziness, fever, chills, and cough.
- Pain or stiffness in the muscles and joints.
- Nausea, vomiting, diarrhoea (loose and frequent stools), decreased appetite, and stomach pain.
- Skin reactions such as flushing (reddening of the skin), rash, hives, and itching
Most of these side effects are mild and temporary. Consult your healthcare professional if any of the side effects become severe or bothersome.
What are some rare but serious side-effects that I need to seek medical advice immediately?
The symptoms of a drug allergy include one or more of the following:
- Swollen face/eyes/lips/tongue
- Difficulty in breathing
- Itchy skin rashes over your whole body
You can also find out about drug allergies by watching these videos:
For videos in 中文, Melayu and தமிழ், click here
If you experience any of these symptoms, you should stop your medication immediately and seek medical attention.
What food or medication should I avoid when I take or use this medication?
Some medications might interact with this medication and affect how it works. These include bypassing agents such as activated prothrombin complex concentrate (aPCC; FEIBA®) and NovoSeven® (recombinant coagulation factor VIIa) and any form of Factor VIII. Serious and potentially life-threatening side effects can occur when aPCC is used in patients who are also receiving emicizumab. Carefully follow your healthcare provider’s instructions regarding when to use the bypassing agents or factor VIII and the dose and schedule to use for breakthrough bleeds treatment.
How should I store this medication?
Store in the refrigerator between 2–8°C. Do not freeze.
Keep this medication away from children.
How do I throw away this medication safely?
You may throw the empty vials away along with the used needles and syringes into a metal tin or thick plastic container (eg. detergent bottles). You can also buy a container specially designed to throw sharp items, known as a sharps box, to prevent any injuries due to the needles.
What else should I know about this medication?
Inform the doctor that you are receiving emicizumab for the treatment of haemophilia A before going for laboratory tests that measure how well your blood is clotting. Your doctor may refer to these laboratory tests as “coagulation tests” and “inhibitor assays”. This is because the presence of Emicizumab in the blood may interfere with some of these laboratory tests, leading to inaccurate results.
Practise safety precautions to prevent injuries such as covering or cushioning sharp edges of furniture at home and wearing appropriate protective gear during exercises. Engage in low-impact exercises such as swimming, walking and avoid high-impact or contact sports such as rugby or martial arts. Seek immediate attention if you had a fall or sustained any injuries as serious internal bleeding may occur.
Disclaimer
Please take note that the above is not a complete list of all possible side-effects. If you have any concerns about your medication or if you have other side-effects that you think are caused by this medication, please consult your doctor or pharmacist. If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.
This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (NHG Health, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.
Contributed By
- Pharmaceutical Society of Singapore
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