Slideshows Images Quizzes

Copyright © 2018 by RxList Inc. RxList does not provide medical advice, diagnosis or treatment. See additional information.


Last reviewed on RxList: 3/29/2021

What is Lemtrada and how is it used?

Lemtrada is a prescription medicine used to treat relapsing forms of multiple sclerosis (MS), to include relapsing-remitting disease and active secondary progressive disease, in adults. Since treatment with Lemtrada can increase your risk of getting certain conditions and diseases, Lemtrada is generally prescribed for people who have tried 2 or more MS medicines that have not worked well enough. Lemtrada is not recommended for use in patients with clinically isolated syndrome (CIS).

It is not known if Lemtrada is safe and effective for use in children under 17 years of age.

What are the possible side effects of Lemtrada?

Lemtrada may cause serious side effects including:

  • thyroid problems. Some people who receive Lemtrada may get thyroid problems including an overactive thyroid (hyperthyroidism) or an underactive thyroid (hypothyroidism). Your healthcare provider will do blood tests to check how your thyroid is working. Call your healthcare provider if you have any of the symptoms of thyroid problems.
  • Symptoms of hyperthyroidism may include:
    • excessive sweating
    • eye swelling
    • unexplained weight loss
    • nervousness
    • fast heartbeat
  • Symptoms of hypothyroidism may include:
    • unexplained weight gain
    • worsening tiredness
    • feeling cold
    • constipation
  • low blood counts (cytopenias). Lemtrada may cause a decrease in some types of blood cells. Some people with these low blood counts have increased infections. Symptoms of cytopenias may include:
    • weakness
    • dark urine
    • chest pain
    • fast heartbeat
    • yellowing of the skin or whites of eyes (jaundice)

Your healthcare provider will do blood tests to check for cytopenias. Call your healthcare provider right away if you have symptoms listed above.

  • inflammation of the liver. Call your healthcare provider right away if you have symptoms such as unexplained nausea, stomach pain, tiredness, loss of appetite, yellowing of skin or whites of eyes, or bleeding or bruising more easily than normal.
  • hemophagocytic lymphohistiocytosis (HLH). Lemtrada may increase the risk of a type of overactivity of the immune system (hemophagocytic lymphohistiocytosis) that can be fatal, especially if not diagnosed and treated early. Call your healthcare provider right away if you have symptoms such as fever, swollen glands, skin rash, or new nervous system problems, such as seizures, changes in your thinking or level of alertness, or new or worsening unsteadiness or trouble walking. These symptoms have happened in people taking Lemtrada about 13 months to 33 months after they started taking Lemtrada.
  • serious infections. Lemtrada may cause you to have serious infections while you receive and after receiving a treatment course. Serious infections may include:
    • Listeria. People who receive Lemtrada have an increased chance of getting an infection caused by the bacteria, Listeria, which can lead to significant complications or death. Avoid foods that may be a source for Listeria (for example, deli meat, unpasteurized milk and cheese products, soft cheeses, or undercooked meat, seafood or poultry) or make sure that the food you eat which may contain Listeria is heated well if you receive treatment with Lemtrada.
    • herpes viral infections. Some people taking Lemtrada have an increased chance of getting herpes viral infections. Your healthcare provider will prescribe medicines to reduce your chances of getting these infections. Take these medicines exactly as your healthcare provider tells you to.
    • human papilloma virus (HPV). Females have an increased chance of getting a cervical HPV infection. If you are a female, you should have an HPV screening each year.
    • tuberculosis. Your healthcare provider should check you for tuberculosis before you receive Lemtrada.
    • fungal infections.

Call your healthcare provider right away if you have symptoms of a serious infection, such as fever or swollen glands. You may need to go to the hospital for treatment if you get a serious infection. It is important to tell the healthcare providers that you have received Lemtrada.

Talk to your healthcare provider before you get vaccinations after receiving Lemtrada. Certain vaccinations may increase your chances of getting infections.

  • Progressive multifocal leukoencephalopathy (PML). A rare brain infection that usually leads to death or severe disability has been reported with Lemtrada. Symptoms of PML get worse over days to weeks. It is important that you call your doctor right away if you have any new or worsening medical problems that have lasted several days, including problems with:
    • thinking
    • eyesight
    • strength
    • balance
    • weakness on 1 side of your body
    • using your arms or legs
  • Inflammation of the gallbladder without gallstones (acalculous cholecystitis). Lemtrada may increase your chance of getting inflammation of the gallbladder without gallstones, a serious medical condition that can be life-threatening. Call your healthcare provider right away if you have any of the following symptoms of acalculous cholecystitis, which may include:
    • stomach pain or discomfort
    • fever
    • nausea or vomiting
  • swelling of lung tissue (pneumonitis). Some people have had swelling of the lung tissue while receiving Lemtrada. Call your healthcare provider right away if you have the following symptoms:
    • shortness of breath
    • chest pain or tightness
    • cough
    • coughing up blood
    • wheezing

The most common side effects of Lemtrada include:

  • rash
  • fungal infection
  • headache
  • joint pain
  • thyroid problems
  • pain in your arms or legs
  • fever
  • back pain
  • swelling of your nose and throat (nasopharyngitis)
  • diarrhea
  • nausea
  • sinus infection
  • urinary tract infection
  • mouth pain or sore throat
  • feeling tired
  • tingling sensation
  • trouble sleeping
  • dizziness
  • upper respiratory tract infection
  • stomach pain
  • herpes viral infection
  • sudden redness in face, neck, or chest
  • hives
  • vomiting
  • itching

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of Lemtrada. For more information, ask your healthcare provider or pharmacist.

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

Lemtrada (alemtuzumab) is a recombinant humanized IgG1 kappa monoclonal antibody used to treat patients with relapsing forms of multiple sclerosis (MS). Because of its safety profile, the use of Lemtrada should generally be reserved for patients who have had an inadequate response to two or more drugs indicated for the treatment of MS. Common side effects of Lemtrada include:

  • rash,
  • headache,
  • fever,
  • runny nose,
  • sore throat,
  • nasal congestion,
  • nausea,
  • urinary tract infection,
  • fatigue,
  • insomnia,
  • upper respiratory tract infection,
  • herpes viral infection,
  • hives,
  • itching,
  • thyroid gland disorders,
  • fungal infection,
  • joint pain,
  • pain in extremity,
  • back pain,
  • diarrhea,
  • sinus infection,
  • mouth and throat pain,
  • numbness or tingling, dizziness,
  • abdominal pain,
  • flushing of the face/neck/chest,
  • vomiting,
  • cough,
  • chills,
  • changes in sense of taste,
  • flu symptoms,
  • skin swelling,
  • indigestion,
  • blood in the urine,
  • shortness of breath,
  • fast heart beat,
  • anxiety,
  • weakness, or
  • muscle pain

The recommended dosage of Lemtrada is 12 mg/day administered by intravenous infusion for 2 treatment courses: First Treatment Course: 12 mg/day on 5 consecutive days (60 mg total dose; Second Treatment Course: 12 mg/day on 3 consecutive days (36 mg total dose) administered 12 months after the first treatment course. Lemtrada may interact with other drugs. Tell your doctor all medications and supplements you use. During pregnancy, Lemtrada should be used only if prescribed. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Our Lemtrada (alemtuzumab) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.



  • LEMTRADA causes serious, sometimes fatal, autoimmune conditions such as immune thrombocytopenia and anti-glomerular basement membrane disease. Monitor complete blood counts with differential, serum creatinine levels, and urinalysis with urine cell counts at periodic intervals for 48 months after the last dose of LEMTRADA [see WARNINGS AND PRECAUTIONS].
  • LEMTRADA causes serious and life-threatening infusion reactions. LEMTRADA must be administered in a setting with appropriate equipment and personnel to manage anaphylaxis or serious infusion reactions. Monitor patients for two hours after each infusion. Make patients aware that serious infusion reactions can also occur after the 2-hour monitoring period [see WARNINGS AND PRECAUTIONS].
  • Serious and life-threatening stroke (including ischemic and hemorrhagic stroke) has been reported within 3 days of LEMTRADA administration. Instruct patients to seek immediate medical attention if symptoms of stroke occur [see WARNINGS AND PRECAUTIONS].
  • LEMTRADA may cause an increased risk of malignancies, including thyroid cancer, melanoma, and lymphoproliferative disorders. Perform baseline and yearly skin exams [see WARNINGS AND PRECAUTIONS].
  • Because of the risk of autoimmunity, infusion reactions, and malignancies, LEMTRADA is available only through restricted distribution under a Risk Evaluation Mitigation Strategy (REMS) Program. Call 1-855-676-6326 to enroll in the LEMTRADA REMS program [see WARNINGS AND PRECAUTIONS].


Alemtuzumab is a recombinant humanized IgG1 kappa monoclonal antibody directed against the cell surface glycoprotein, CD52. Alemtuzumab has an approximate molecular weight of 150 kD. Alemtuzumab is produced in mammalian cell (Chinese hamster ovary) suspension culture in a nutrient medium containing neomycin. Neomycin is not detectable in the final product.

LEMTRADA (alemtuzumab) injection is a sterile, clear and colorless to slightly yellow, solution (pH 7.2 ± 0.2) for intravenous infusion.

Each 1 mL of solution contains 10 mg alemtuzumab, dibasic sodium phosphate (1.15 mg), disodium edetate dihydrate (0.0187 mg), polysorbate 80 (0.1 mg), potassium chloride (0.2 mg), potassium dihydrogen phosphate (0.2 mg), sodium chloride (8 mg), and Water for Injection, USP.