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Alemtuzumab (Lemtrada)

Generic Name: Alemtuzumab (Lemtrada) (ay lem TU zoo mab)
Brand Name: Lemtrada

Medically reviewed by Last updated on Jun 3, 2019.


  • This medicine may cause very bad and sometimes life-threatening infusion reactions. You will be closely watched during the infusion and for some time after. Very bad infusion reactions may also happen up to 24 hours or longer after you get alemtuzumab (lemtrada). Tell your doctor right away if you have chest pain; passing out; fast or slow heartbeat; a heartbeat that does not feel normal; fever; hives; itching; rash; very bad headache or dizziness; shortness of breath or trouble breathing; swelling of the mouth, face, lips, throat, or tongue; tightness in the chest or throat; hoarseness that is not normal; or wheezing.
  • Other infusion reactions include change in taste, chills, dizziness, flushing, upset stomach, pain, feeling tired, or not able to sleep. Talk with the doctor.
  • This medicine may cause very bad and sometimes deadly autoimmune problems like some blood problems. Side effects may happen while you get alemtuzumab (lemtrada) and for 4 years after you stop treatment. You will need to have your blood work and urine checked while getting alemtuzumab (lemtrada) and after getting it as you have been told by your doctor. Talk with your doctor.
  • Very bad and sometimes deadly infections have happened in patients who take alemtuzumab (lemtrada). If you have any infection, are taking antibiotics now or in the recent past, or have had many infections, talk with your doctor.
  • Rarely, strokes and tears in blood vessels in the head and neck have happened with alemtuzumab when used for MS (multiple sclerosis). Most of the time, this happened within 1 day after getting alemtuzumab (lemtrada) but can happen a few days after treatment. These health problems can lead to long-term disability and can be deadly. Closely read the part in this leaflet which lists when to call your doctor.
  • This medicine may raise the chance of cancer like thyroid cancer, skin cancer, and lymphoma. Have your skin checked and other lab tests done as you have been told by your doctor. Talk with your doctor.

Uses of Alemtuzumab:

  • It is used to treat MS (multiple sclerosis).
  • It may be given to you for other reasons. Talk with the doctor.

What do I need to tell my doctor BEFORE I take Alemtuzumab?

  • If you have an allergy to alemtuzumab or any other part of alemtuzumab (lemtrada).
  • If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
  • If you have an infection.
  • If you have a weak immune system or a disease that may cause a weak immune system like HIV.
  • If you have ever had any of these health problems: Any type of cancer or PML.
  • If you are breast-feeding or plan to breast-feed.

This is not a list of all drugs or health problems that interact with alemtuzumab (lemtrada).

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take alemtuzumab (lemtrada) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Alemtuzumab?

  • Tell all of your health care providers that you take alemtuzumab (lemtrada). This includes your doctors, nurses, pharmacists, and dentists.
  • You may have more chance of getting an infection. Wash hands often. Stay away from people with infections, colds, or flu.
  • Call your doctor right away if you have any signs of infection like fever, chills, flu-like signs, very bad sore throat, ear or sinus pain, cough, more sputum or change in color of sputum, pain with passing urine, mouth sores, or a wound that will not heal.
  • You may bleed more easily. Be careful and avoid injury. Use a soft toothbrush and an electric razor.
  • Call your doctor right away if you have any signs of bleeding problems, like bruising; black, tarry, or bloody stools; bleeding gums; blood in the urine; coughing up blood; cuts that take a long time to stop bleeding; feel dizzy; feeling very tired or weak; nosebleeds; pain or swelling; throwing up blood or throw up that looks like coffee grounds; or very bad headache.
  • Gallbladder problems have happened with alemtuzumab (lemtrada). Sometimes, these problems can be life-threatening. Talk with the doctor.
  • A very bad brain problem called progressive multifocal leukoencephalopathy (PML) may happen with alemtuzumab (lemtrada). It may cause disability or can be deadly. Tell your doctor right away if you have signs like confusion, memory problems, low mood (depression), change in the way you act, change in strength on 1 side is greater than the other, trouble speaking or thinking, change in balance, or change in eyesight.
  • Certain kidney problems have happened with alemtuzumab (lemtrada). These problems can lead to kidney failure, dialysis, or transplant, and can be life-threatening. Call your doctor right away if you have signs of kidney problems like unable to pass urine, change in the amount of urine passed, blood in the urine, or a big weight gain.
  • People taking alemtuzumab (lemtrada) may have a higher chance of getting an infection caused by the listeria bacteria. These infections have happened from 3 days to 8 months after a dose. Some of these infections have been deadly. Before taking alemtuzumab (lemtrada) and during treatment, avoid foods that may be a source of listeria or make sure that the food you eat that may contain listeria is heated well. Some foods that may be a source of listeria include deli meat; unpasteurized milk and cheese products; or undercooked meat, seafood, or chicken. If you have questions, talk with your doctor.
  • Hepatitis B or C testing may be done. A hepatitis B or C infection may get worse while taking alemtuzumab (lemtrada).
  • Call your doctor right away if you have signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
  • Do not give to a child younger than 17 years of age.
  • This medicine may cause harm to the unborn baby if you take it while you are pregnant.
  • Women must use birth control while taking alemtuzumab (lemtrada) and for some time after the last dose. Ask your doctor how long to use birth control. If you get pregnant, call your doctor right away.

How is this medicine (Alemtuzumab) best taken?

Use alemtuzumab (lemtrada) as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • It is given as an infusion into a vein over a period of time.
  • Other drugs may be given to help with infusion side effects.
  • Make sure you are up to date with all your vaccines at least 6 weeks before treatment with alemtuzumab (lemtrada). Talk with your doctor.
  • Talk with your doctor before getting any vaccines. Use of some vaccines with alemtuzumab (lemtrada) may either raise the chance of an infection or make the vaccine not work as well.
  • All females taking alemtuzumab (lemtrada) must have an HPV screening each year. Talk with your doctor.
  • You will need a TB (tuberculosis) test before starting alemtuzumab (lemtrada).

What do I do if I miss a dose?

  • Call your doctor to find out what to do.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of gallbladder problems like pain in the upper right belly area, right shoulder area, or between the shoulder blades; yellow skin or eyes; fever with chills; bloating; or very upset stomach or throwing up.
  • Signs of lung or breathing problems like shortness of breath or other trouble breathing, cough, or fever.
  • Signs of thyroid problems like change in weight; feeling nervous, excitable, restless, or weak; hair thinning; depression; neck swelling; not able to focus; trouble with heat or cold; menstrual changes; shakiness; or sweating.
  • Signs of thyroid cancer like new lump or swelling in the neck, pain in the front of the neck, cough that does not go away, change in voice that does not go away like hoarseness, or trouble swallowing or breathing.
  • Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.
  • Feeling confused.
  • Trouble walking.
  • Neck pain.
  • Chest pain or pressure or a fast heartbeat.
  • A burning, numbness, or tingling feeling that is not normal.
  • Shortness of breath.
  • Feeling very tired or weak.
  • Redness or white patches in mouth or throat.
  • Swollen gland.
  • Change in color or size of a mole.
  • A skin lump or growth.
  • Night sweats.
  • Low mood (depression).
  • If you are planning to harm yourself or the want to harm yourself gets worse.
  • Swelling in the arms or legs.
  • Stiff neck.
  • Vaginal itching or discharge.

What are some other side effects of Alemtuzumab?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Anxiety.
  • Headache.
  • Upset stomach or throwing up.
  • Stomach pain or diarrhea.
  • Feeling tired or weak.
  • Trouble sleeping.
  • Pain in arms or legs.
  • Dizziness.
  • Flushing.
  • Back, muscle, or joint pain.
  • Muscle spasm.
  • Muscle weakness.
  • Nose or throat irritation.
  • Change in taste.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Alemtuzumab?

  • If you need to store alemtuzumab (lemtrada) at home, talk with your doctor, nurse, or pharmacist about how to store it.

Consumer information use

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
  • Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
  • This medicine comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time alemtuzumab (lemtrada) is refilled. If you have any questions about alemtuzumab (lemtrada), please talk with the doctor, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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