Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. Leqembi


Lecanemab-irmb injection is used to treat Alzheimer's disease.

This medicine is to be given only by or under the supervision of your doctor.

This product is available in the following dosage forms:

  • Solution

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of lecanemab-irmb injection in the pediatric population. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of lecanemab-irmb injection in the elderly.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Proper Use

A nurse or other trained health professional will give you this medicine in a medical facility. It is given through a needle placed into one of your veins. It must be given slowly, so the needle will have to remain in place for at least 1 hour. This medicine is usually given every 2 weeks.

This medicine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions.

Your doctor will do magnetic resonance imaging (MRI) scans before the first treatment, and at certain times during treatment with this medicine.

Your doctor may give you other medicines (eg, allergy medicine, NSAID, steroid medicine) before receiving this medicine to help prevent infusion-related reactions.

Missed Dose

Call your doctor or pharmacist for instructions.


It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly. Blood tests may be needed to check for unwanted effects.

This medicine may cause amyloid related imaging abnormalities (ARIA), which can be seen as temporary swelling or bleeding in the brain. Call your doctor right away if you have changes in vision, confusion, dizziness, headache, nausea, or seizures.

This medicine may cause infusion-related reactions, which can be life-threatening and require immediate medical attention. Check with your doctor right away if you have back pain, blurred vision, chest tightness, chills, confusion, cough, dizziness, dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position, drowsiness, fever, flushing, general feeling of discomfort or illness, headache, joint pain, muscle aches and pains, nausea and vomiting, nervousness, pale skin, pounding in the ears, runny nose, shivering, slow or fast heartbeat, sore throat, sweating, trouble breathing, trouble sleeping, or unusual tiredness or weakness.

This medicine may cause serious allergic reactions, including anaphylaxis and angioedema, which can be life-threatening and require immediate medical attention. Check with your doctor right away if you have a cough, difficulty swallowing, dizziness, fast heartbeat, large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs, rash, itching, trouble breathing, or unusual tiredness or weakness after receiving this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

  1. Back pain
  2. blurred or changes in vision
  3. chest tightness
  4. chills
  5. confusion
  6. diarrhea
  7. dizziness
  8. dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  9. drowsiness
  10. feeling shaky
  11. fever
  12. flushing
  13. general feeling of discomfort or illness
  14. headache
  15. joint pain
  16. loss of appetite
  17. muscle aches and pain
  18. nausea and vomiting
  19. nervousness
  20. pale skin
  21. pounding in the ears
  22. runny nose
  23. seizures
  24. shivering
  25. slow or fast heartbeat
  26. sore throat
  27. sweating
  28. trouble breathing
  29. trouble sleeping
  30. unusual tiredness or weakness

Less common

  1. Cough or hoarseness
  2. lower back or side pain
  3. painful or difficult urination

Incidence not known

  1. Cough
  2. difficulty swallowing
  3. dizziness
  4. fast heartbeat
  5. hives, itching, skin rash
  6. large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs
  7. puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.