Lecanemab belongs to the class of medications called monoclonal antibodies. Monoclonal antibodies recognize specific proteins in the body and help the immune system identify these proteins and remove them. Specifically, it is an anti-amyloid beta monoclonal antibody. This medication is used to treat mild or early Alzheimer’s disease.
Lecanemab works by helping the immune system remove amyloid-beta proteins in the brain. When these proteins build up in the brain, they form plaques that impair memory, reduce problem-solving ability and ability to concentrate, common symptoms of early Alzheimer’s disease.
This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.
Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
Each mL of preservative-free, sterile, clear to opalescent, and colourless to pale yellow solution, contains 100 mg of lecanemab. Nonmedicinal ingredients: arginine hydrochloride, histidine, histidine hydrochloride monohydrate, polysorbate 80, and water for injection.
Lecanemab is given as an intravenous (into a vein) infusion. The usual dose is 10 mg per kilogram of body weight, given by intravenous infusion over 1 hour every 2 weeks. If you experience an infusion reaction, the rate of the infusion may be slowed down, taking longer than 1 hour.
Lecanemab is usually given under the supervision of a doctor in a hospital or similar setting with access to sterile equipment for preparation and the medical training to manage side effects, such as a severe allergic reaction. Your doctor will want you to wait in the hospital or clinic for 2.5 hours after the first infusion, to make sure you don’t have an allergic or infusion reaction.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
It is important this medication be given exactly as recommended by your doctor. If you miss an appointment to receive lecanemab, contact your doctor as soon as possible to reschedule your appointment.
Store this medication in the refrigerator in the outer carton to protect it from light. Do not freeze or shake. Keep out of reach of children.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Do not take this medication if you:
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Stop taking the medication and seek immediate medical attention if any of the following occur:
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Allergic reactions: Lecanemab can cause infusion-related reactions, like other monoclonal antibodies. In these situations, the body recognizes the medication as an intruder and the immune system takes over, defending the body from the antibodies. If you experience symptoms of an infusion reaction, such as flu-like symptoms, fever, chills, nausea or vomiting, difficulty breathing, severe dizziness, chest tightness or stomach cramps, let your healthcare team know immediately. Additional medications can be given to reduce these symptoms and the rate of the infusion can also be reduced.
Amyloid related imaging abnormalities (ARIA): When lecanemab starts to break down the amyloid beta plaques in the brain, the blood vessels become more permeable to the flow of blood and fluids from the blood vessels into the area of the brain where the plaque had been located. This can cause bleeding into the brain or a buildup of fluid in small parts of the brain.
While this often happens without any symptoms, ARIA can be life-threatening. Your doctor will schedule an MRI before you start using this medication and several MRIs regularly after you start. If you experience symptoms of ARIA, such as headache, confusion, vision changes, dizziness, nausea or difficulty walking, contact your doctor immediately. Rarely, seizures may occur. These symptoms generally go away over time, but it is important to confirm with your healthcare team that they are not signs of a severe bleed or buildup of fluid on the brain.
Driving or operating machinery: Lecanemab can cause dizziness and confusion as well as decreased coordination. These side effects can impact your ability to drive or operate machinery safely. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how you are affected by this medication.
Increased bleeding risk: If you need to take medications to prevent or treat blood clots (blood thinners; warfarin, ticagrelor), discuss with your doctor whether this medication should be paused.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Women who want to become pregnant should stop using this medication for at least 3 months before trying to conceive.
Breast-feeding: It is not known if lecanemab passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children.
For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.
If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.
All material copyright MediResource Inc. 1996 – 2026. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/drug/getdrug/Leqembi