In the U.S.—

In Canada—

• Monoclonal antibody
• immunosuppressant

Muromonab-CD3 (myoo-roe-MOE-nab cee-dee-three) is a monoclonal antibody. It is used to reduce the body's natural immunity in patients who receive organ (for example, kidney) transplants.

When a patient receives an organ transplant, the body's white blood cells will try to get rid of (reject) the transplanted organ. Muromonab-CD3 works by preventing the white blood cells from doing this.

The effect of muromonab-CD3 on the white blood cells may also reduce the body's ability to fight infections. Before you begin treatment, you and your doctor should talk about the good this medicine will do as well as the risks of using it.

Muromonab-CD3 is to be administered only by or under the immediate supervision of your doctor. It is available in the following dosage form:

Parenteral
• Injection (U.S. and Canada)

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 muromonab-CD3, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to muromonab-CD3 or to rodents (such as mice or rats). Muromonab-CD3 is grown in a mouse cell culture. Also tell your health care professional if you are allergic to any other substance, such as preservatives.

Pregnancy—Studies have not been done in either humans or animals. Muromonab-CD3 may cross the placenta, but it is not known whether it causes harmful effects on the fetus. Before receiving this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—It is not known whether muromonab-CD3 passes into breast milk. Muromonab-CD3 has not been reported to cause problems in nursing babies. However, it may be necessary for you to stop breast-feeding during treatment. Be sure you have discussed the risks and benefits of the medicine with your doctor.

Children—There is no specific information comparing use of muromonab-CD3 in children with use in other age groups. However, children are more likely to get dehydrated from the diarrhea and vomiting that may be caused by this medicine.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of muromonab-CD3 in the elderly with use in other age groups.

Other medicines—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. When you are receiving muromonab-CD3, it is especially important that your health care professional know if you are taking any of the following:

• Azathioprine (e.g., Imuran) or
• Chlorambucil (e.g., Leukeran) or
• Corticosteroids (cortisone-like medicine) or
• Cyclophosphamide (e.g., Cytoxan) or
• Cyclosporine (e.g., Sandimmune) or
• Cytarabine (e.g., Cytosar-U) or
• Mercaptopurine (e.g., Purinethol) or
• Tacrolimus (e.g., Prograf)—There may be an increased risk of infection and development of cancer because muromonab-CD3 reduces the body's ability to fight them

• Angina (chest pain) or
• Circulation problems or
• Convulsions (seizures) or
• Heart attack (recent) or
• Heart problems, other, or
• Kidney problems or
• Lung problems or
• Nervous system problems—Increased risk of serious unwanted effects from muromonab-CD3

• Blood clots (history of)—Risk of blood clots in transplanted organ or blood vessels

• Chickenpox (including recent exposure) or
• Herpes zoster (shingles)—Risk of severe disease affecting other parts of the body

• Infection—Muromonab-CD3 decreases your body's ability to fight infection

Dosing—

The dose of muromonab-CD3 may be different for different patients. Muromonab-CD3 is usually given by a doctor or nurse in the hospital. The following information includes only the average doses of muromonab-CD3:

• For injection dosage form:
  • To prevent organ transplant rejection:
    • Adults—5 milligrams (mg) injected into a vein once a day.
    • Children less than 12 years of age—Dose is based on body weight and must be determined by your doctor.

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

While you are being treated with muromonab-CD3 and after you stop treatment with it, do not have any immunizations (vaccinations) without your doctor's approval. Muromonab-CD3 may lower your body's resistance. For some immunizations, there is a chance you might get the infection the immunization is meant to prevent. For other immunizations, it may be especially important to receive the immunization to prevent a disease. In addition, other persons living in your house should not take oral polio vaccine since there is a chance they could pass the polio virus on to you. Also, avoid persons who have recently taken oral polio vaccine. Do not get close to them and do not stay in the same room with them for very long. If you cannot take these precautions, you should consider wearing a protective face mask that covers the nose and mouth.

Treatment with muromonab-CD3 may also increase the chance of getting other infections. If you can, avoid people with colds or other infections. If you think you are getting a cold or other infection, check with your doctor.

This medicine commonly causes chest pain, dizziness, fever and chills, shortness of breath, stomach upset, and trembling within a few hours after the first dose. These effects should be less after the second dose. However, check with your doctor or nurse immediately if you have chest pain, rapid or irregular heartbeat, shortness of breath or wheezing, or swelling of the face or throat after any dose.

Along with its needed effects, a medicine may cause some unwanted effects.

Because of the way that muromonab-CD3 acts on the body, there is a chance that it may cause effects that may not occur until years after the medicine is used. These delayed effects may include certain types of cancer, such as lymphomas and skin cancers. Discuss these possible effects with your doctor.

Although not all of the following side effects may occur, if they do occur, they may need medical attention.

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

• Less common
  • Chest pain;  rapid or irregular heartbeat ;  shortness of breath or wheezing;  swelling of face or throat 
  
  

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Diarrhea;  dizziness or faintness;  fever and chills;  general feeling of discomfort or illness;  headache;  muscle or joint pain;  nausea and vomiting 
  
  

• Less common or rare
  • Confusion;  black, tarry stools;  blood in urine or stools;  convulsions (seizures);  cough or hoarseness;  hallucinations (seeing, hearing, or feeling things that are not there);  itching or tingling;  loss of hearing or vision;  lower back or side pain;  painful or difficult urination;  pinpoint red spots on skin;  skin rash;  sores, ulcers, or white spots on the lips or in the mouth;  stiff neck;  swollen or painful glands;  tightness in the chest;  trembling and shaking of hands;  troubled breathing;  unusual sensitivity of eyes to light;  unusual bleeding or bruising;  unusual tiredness;  weakness 
  
  

After you stop using this medicine, it may still produce some side effects that need medical attention. During this period of time check with your doctor if you notice the following side effects:

• Fever and chills 

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