Print this page

Alemtuzumab Treatment

Please note that “alemtuzumab” and “Lemtrada” are different names for the same drug. The drug was also previously known as “Campath.” Throughout this information sheet, we will use the name alemtuzumab.


Alemtuzumab is licensed to treat adults with active relapsing-remitting multiple sclerosis (MS), it is not recommended for patients with progressive forms of MS, inactive disease or who are stable on current treatments.

Benefits of Alemtuzumab in Multiple Sclerosis

Alemtuzumab has been studied in 2 large clinical trials which compared it to an alternative established drug called Rebif® (Interferon Beta1a).  In these trials it decreased relapse rates by approximately an additional 50% compared to established treatment.

How is Alemtuzumab Given?

Alemtuzumab is given as a drip into a vein in your arm, otherwise called an infusion over four hours.

For the first course of alemtuzumab, you will have an infusion every day for five consecutive days. There is no further alemtuzumab until at least 12 months later, when you will receive a similar daily infusion but for three days only. These infusions are given in hospital as an inpatient. You will also receive an intravenous course of steroids (methylprednisolone) given as an infusion for approximately 1 hour just before each dose of alemtuzumab. 

What are the side-effects of Alemtuzumab?

The risks described below are the well known ones based upon experience in clinical trials. But it is possible that new side-effects of alemtuzumab may emerge in the future.

Infusion-related risks

The first or second dose of alemtuzumab may be associated with the symptoms listed below. Your doctor will also give you an antihistamine and paracetamol, as well as steroids, before the alemtuzumab infusion to reduce the side effects further. The possible side effects are:


  • Worsening of current or old symptoms from MS. This lasts only for a few hours and does not lead to permanently increased disability.
  • Rash (raised itchy red spots on the skin) which can be treated with anti-histamine medication.
  • Fever, headache, and fatigue – may last for a few hours.
  • Rigor/chills (feeling cold and shaking).
  • Nausea, vomiting, and/or diarrhoea – this happens rarely.
  • Shortness of breath and/or spasms in the windpipe, especially in patients with asthma.
  • Hypotension (a drop in blood pressure) that may cause dizziness, headache and fatigue.
  • Most patients have mild to moderate infusion reactions, but 3% have serious reactions which can be life threatening.

Risk of bleeding from a Low Platelet Count

Alemtuzumab treatment in people with multiple sclerosis has been associated with a low platelet count (called thrombocytopenia”). Platelets help to form blood clots. Therefore a low platelet count may lead to an increased risk of bleeding and so can cause easy bruising, easy bleeding of the gums, nose bleeds, unusually heavy menstrual periods, or any other unusual bruising or bleeding. Thrombocytopenia can cause serious complications and it can be fatal.  If you experience these signs you should consult a doctor without delay, it does not need to be your neurologist. There have been cases of thrombocytopenia (low platelet count) in approximately 1% of alemtuzumab treated patients. To identify any drop in your platelet levels as early as possible, all people treated with alemtuzumab must have monthly blood tests for four years after receiving their final dose of alemtuzumab.

Food-borne illnesses

For one month after each alemtuzumab dose, there is an increased risk of certain infections from a bacteria called Listeria from unpasteurised milk products. A severe infection may mean you would need treatment in hospital and could even result in death.  The risk of Listeria infection can be reduced significantly by taking an antibiotic called co-trimoxazole (or amoxicillin if you are allergic to co-trimoxazole) and following simple dietary advice (foods to avoid) for one month after each treatment. You will be provided with advice on food including food storage, preparation and a list of foods to avoid.

Viral infections (chicken pox, shingles or herpes simplex infections)

You will need to take a tablet called aciclovir for one month after treatment to decrease the risk of viral infections.  If you receive alemtuzumab, you should avoid contact with anyone who has symptoms of chicken pox or shingles. If you are exposed to these infections, please tell your doctor as soon as possible. If you have a history of herpes infections or cold sores, they may recur following treatment with alemtuzumab.

Human immunodeficiency virus (HIV) and hepatitis B and C infections

If you have ever tested positive for these viruses you should not receive alemtuzumab and you should inform your neurologist.  Blood tests to check for hepatitis and HIV will be performed in all patients prior to treatment with alemtuzumab.

Thyroid problems

Diseases of the thyroid gland are seen in over a third (36%) of patients treated with alemtuzumab.  This is most commonly an overactive thyroid gland (Gravesdisease). If untreated, the symptoms of Gravesdisease would be: increased sweating, anxiety, weight loss, tremor and sometimes pain in the neck. If needed, the first treatment is tablets. These are normally given for 6 months and then stopped. If the thyroid gland still remains overactive, it can be permanently suppressed by radioactive iodine treatment. After radioactive treatment, it is usually necessary to take thyroid tablets for life. One symptom of Gravesdisease that may not be easily controlled by tablets is swelling of the eyes. This progressive swelling may look unpleasant and may even compromise vision. It may require treatment with steroids, radiotherapy or surgery. If you develop thyroid disease you will need to be referred to a local specialist.  Thyroid disorders can be detected by blood tests and you should have your thyroid function tested by a blood test every 3 months for 4 years after your last infusion

Goodpasture’s Syndrome

This is a very rare disease that affects the lungs and kidneys in 0.3% of treated patients. It often leads to kidney failure and the need for dialysis or even kidney transplantation.  Treatment can be more effective if begun very early and so it is essential that you have regular monthly blood tests for 4 years after your last infusion.

Risks Associated with Methylprednisolone

People taking methylprednisolone can experience an unpleasant taste in the mouth, tingling in their limbs, difficulty sleeping and a burst of energy. Rarely stomach bleeds can happen. These symptoms all resolve soon after infusion.

Fertility and Harm to the Unborn Child

There is no information available about the effects of alemtuzumab on fertility and pregnancies, and it is potentially harmful. There is a possibility that alemtuzumab might temporarily reduce or affect fertility in both men and women.  Alemtuzumab may be harmful to an unborn child. Pregnant or breastfeeding women should not be given alemtuzumab. Both men and women who are capable of childbearing should use an effective form of birth control for 4 months after each dose of alemtuzumab. If you become pregnant, you should notify your doctor and let your MS specialist know so that management of the pregnancy can be discussed.


You should not receive a live vaccine. This restriction is lifelong and it is important that you check with your doctor before receiving any vaccine. Live vaccines are recommended prior to travelling to some tropical countries and this can make it more difficult or prevent future travel to some countries.

Children are offered a seasonal nasal flu vaccine in the UK which is a live vaccine.  People in your household should not receive this vaccine within 4 weeks of your treatment with alemtuzumab.

Risks of combining Alemtuzumab with other medicines

We do not know all the side effects that may arise from the combination of alemtuzumab with other drugs so you should always discuss the use of any drugs (over-the-counter, prescription, illegal, herbal or nutritional supplement) with your doctor or pharmacist.

Monitoring (Blood and Urine Tests)

Many of the side effects and complications of alemtuzumab can occur several years after the treatment is given.  These can be detected early by blood tests which would allow your doctors to treat these conditions earlier.  For this reason, you must have blood tests every month for 4 years after your last infusion, even if you feel well.

Food Advice for Patients after each course of alemtuzumab

For one month after each alemtuzumab dose, you are at increased risk of Listeria infection. This can be avoided by:

  • avoiding high risk foods
  • always handling food safely
  • avoiding contact with any animal foetuses or afterbirth (placenta).

These foods should be avoided:

  • Ready-to-eat seafood such as smoked fish and smoked mussels, oysters or raw seafood such as sashimi or sushi
  • Pre-prepared or stored salads, including coleslaw and fresh fruit salad
  • Drinks made from fresh fruit and/or vegetables where washing procedures are unknown (excluding pasteurised or canned juices)
  • Pre-cooked meat products which are eaten without further cooking or heating, such as pate, sliced meat, including ham and salami, and cooked diced chicken (often used in sandwich shops)
  • Any unpasteurised milk or foods made from unpasteurised milk
  • Soft serve ice-creams
  • Soft cheeses, such as brie, camembert, ricotta and feta (safe if cooked and served hot)
  • Ready-to-eat foods, including leftover meats, which have been refrigerated for more than one day
  • Dips and salad dressings in which vegetables may have been dipped and raw vegetable garnishes

Safe foods

  • Freshly prepared foods
  • Freshly cooked foods, to be eaten immediately
  • Hard cheeses, cheese spreads, processed cheese
  • Milk - freshly pasteurised and UHT
  • Yoghurt
  • Canned and pickled food

Remember that Listeria can grow in the refrigerator. However, Listeria bacteria are readily killed during cooking. Wash your hands before preparing food and between handling raw and ready-to-eat foods. Keep all food covered. Place all cooked food in the refrigerator within one hour of cooking. Store raw meat, poultry and fish on the lowest shelves of your refrigerator to prevent them dripping onto cooked and ready-to-eat foods. Keep your refrigerator clean and the temperature below 5°C. Strictly observe use-by or best-before dates on refrigerated foods. Do not handle cooked foods with the same utensils (tongs, knives, cutting boards) used on raw foods, unless they have been thoroughly washed with hot soapy water between uses. All raw vegetables, salads and fruits should be well washed before eating or juicing, and consumed fresh. Defrost food by placing it on the lower shelves of a refrigerator or use a microwave oven. Thoroughly cook all food of animal origin, including eggs. Keep hot foods hot (above 60°C) and cold foods cold (at or below 5°C). Reheat food until the internal temperature of the food reaches at least 70°C (piping hot).


What Do I Need To Do After Having Alemtuzumab?

For the first 2 weeks after treatment with alemtuzumab, you may experience more fatigue than you are used to. For the next 4 weeks, you are at special risk of infections. Simple colds and viral infections are common and will be no different in severity or duration if you catch them.

  • Please let your GP and your MS specialist know if you think you may have an infection.
  • If you are on other medication, please check with your doctor or pharmacist first. It is best to avoid herbal or alternative remedies.
  • For one month follow the advice on food preparation and foods to avoid (see above).
  • If you see any doctor or nurse about any health issue, make sure that they know you have received alemtuzumab.
  • Do not have live vaccinations. Make sure that you have all the vaccinations you need before foreign travel (except any live vaccines). Seek specific advice from your travel clinic before foreign travel.
  • Please ensure that you have monthly blood tests through your GP or MS nurse for 4 years after the last infusion to identify any complications of alemtuzumab treatment. Remember that treatment for these complications is more effective if caught early before you have developed any symptoms.
  • After treatment with alemtuzumab if you ever need a transfusion, you should receive irradiated blood components.
  • Look out for side effects of treatment that are listed in this document.
  • Continue to take anti-viral tablets (aciclovir) and anti-biotics (co-trimoxazole) for one month after the last infusion.
  • Women who are capable of childbearing and all men that have partners that are of capable of childbearing must use an effective form of birth control for 4 months after each dose of alemtuzumab.

Contact Numbers:

MS Nurses: 0151 556 4008. Via this phone number we can arrange for an MS nurse to contact you at a convenient time within the next few days. This number is not suitable for urgent problems or enquiries. For urgent matters you should see your GP or attend an Accident and Emergency department as appropriate.

  • Last Updated:
    20 January 2023
  • Review Date:
    20 January 2026
  • Author:
    Pharmacy Team
  • Summary:

    Alemtuzumab is licensed to treat adults with active relapsing-remitting multiple sclerosis (MS), it is not recommended for patients with progressive forms of MS, inactive disease or who are stable on current treatments.

  • Related Service:

Related content