Thalidomide and lenalidomide

Thalidomide (Thalomid®) and lenalidomide (Revlimid®) are prescription medicines used to treat certain cancers and other diseases. 

If you take them during pregnancy, they can cause severe birth defects or the death of your baby. 

Birth defects are health conditions that are present at birth that change the shape or function of one or more parts of the body. They can cause problems in overall health, how the body develops, or in how the body works.

If you’re pregnant or could become pregnant, don’t take thalidomide or lenalidomide. If you take these medicines and are planning to get pregnant, talk to your health care provider about stopping these medicines before you get pregnant. If you get pregnant while taking these medicines, call your health care provider right away.

How can thalidomide and lenalidomide affect your baby?

Taking even just one dose of thalidomide early in pregnancy can affect the way your baby develops. It can cause severe birth defects that affect many body parts, including:  

  • Arms and legs. Some babies are born without arms and legs. Others may have deformed limbs, like very short arms or legs with flipper-like hands or feet.
  • Digestive tract (including the lips and mouth). The digestive tract is made up of organs and tubes that digest the food you eat.
  • Ears. Some babies are born deaf. This means they have complete hearing loss.  
  • Eyes. Some babies are born with small eyes or no eyes. 
  • Genitals (sex organs)
  • Heart
  • Kidneys

Taking thalidomide during pregnancy has been linked with a greater chance of having a baby with autism spectrum disorders (ASDs). These are a group of disorders that can affect a child’s speech, social skills and behavior. 

Experts believe that lenalidomide can cause the same birth defects that thalidomide causes.

What should you do if you’re taking these medicines and think you may be pregnant?

Call your provider right away if:

  • You think you're pregnant.
  • You have a late, irregular or missed menstrual period.
  • You have a change in your menstrual bleeding.
  • You have sex without using two forms of effective birth control.
  • You have unprotected sex with a man who takes these medicines.

If you get pregnant while taking thalidomide or lenalidomide, your provider must alert the company that makes the medicine and the Food and Drug Administration (also called FDA). The FDA is a government agency that checks the safety of medicine and food in this country. 

Are there programs to help prevent birth defects from these medicines?

Yes. Because these medicines can be so harmful to a developing baby, both women and men must register with the THALOMID REMS™ program or the REVLIMID REMS™ program before they can take them. These programs are approved by the FDA. 

Only doctors and pharmacists who are registered in these program can prescribe and give these medicines to their patients. Both men and women who take these medicines must agree to follow strict rules to help prevent pregnant women and women who may become pregnant from having contact with these medicines. 

Women taking these medicines must agree use two different forms of effective birth control and take regular pregnancy tests. They also must agree not to get pregnant:

  • For at least 4 weeks before they start using the medicines
  • While taking the medicines and during any breaks in treatment 
  • For at least 4 weeks after they stop using the medicines

Men who take these medicines can have them in their semen. During ejaculation, a man releases semen. Semen contains sperm. Experts don’t know if semen with thalidomide or lenalidomide can lead to birth defects. But to be safe, men taking these medicines must agree to use condoms anytime they have sex with a woman of childbearing age. 

What health conditions do these medicines treat?

Thalidomide may be used to treat health conditions including:

  • Crohn’s disease. This disease causes inflammation (swelling and redness) of the digestive system. It’s one of a group of diseases called inflammatory bowel disease or IBD. Thalidomide blocks substances that cause swelling.
  • Hansen’s disease (also called leprosy). This is an infection caused by bacteria that affects the skin, nerves and mucous membranes. Mucous membranes are the moist tissues that line certain parts of the inside of your body, like your nose, mouth and lungs. 
  • HIV complications. HIV stands for human immunodeficiency virus. It’s a virus that attacks the body’s immune system and causes AIDS. Thalidomide is used to treat HIV complications, like ulcers in the mouth, diarrhea and Kaposi’s sarcoma (a type of cancer that can involve the skin, mouth, intestines and other organs).
  • Multiple myeloma. This is a cancer of the bone marrow, the soft, fatty tissue inside your bones. Thalidomide makes the body’s immune system stronger to fight cancer cells.

Lenalidomide helps bone marrow make normal blood cells and kills abnormal cells in the bone marrow. It’s usually used to treat myelodysplastic syndrome (also called MDS), a group of conditions that happen when the bone marrow doesn’t make enough healthy blood cells. Lenalidomide also is sometimes used to treat multiple myeloma.


Last reviewed: May, 2014

Thalidomide (Thalomid®) and lenalidomide (Revlimid®) are prescription medicines used to treat certain cancers and other diseases. 

If you take them during pregnancy, they can cause severe birth defects or the death of your baby. 

Birth defects are health conditions that are present at birth that change the shape or function of one or more parts of the body. They can cause problems in overall health, how the body develops, or in how the body works.

If you’re pregnant or could become pregnant, don’t take thalidomide or lenalidomide. If you take these medicines and are planning to get pregnant, talk to your health care provider about stopping these medicines before you get pregnant. If you get pregnant while taking these medicines, call your health care provider right away.

How can thalidomide and lenalidomide affect your baby?

Taking even just one dose of thalidomide early in pregnancy can affect the way your baby develops. It can cause severe birth defects that affect many body parts, including:  

  • Arms and legs. Some babies are born without arms and legs. Others may have deformed limbs, like very short arms or legs with flipper-like hands or feet.
  • Digestive tract (including the lips and mouth). The digestive tract is made up of organs and tubes that digest the food you eat.
  • Ears. Some babies are born deaf. This means they have complete hearing loss.  
  • Eyes. Some babies are born with small eyes or no eyes. 
  • Genitals (sex organs)
  • Heart
  • Kidneys

Taking thalidomide during pregnancy has been linked with a greater chance of having a baby with autism spectrum disorders (ASDs). These are a group of disorders that can affect a child’s speech, social skills and behavior. 

Experts believe that lenalidomide can cause the same birth defects that thalidomide causes.

What should you do if you’re taking these medicines and think you may be pregnant?

Call your provider right away if:

  • You think you're pregnant.
  • You have a late, irregular or missed menstrual period.
  • You have a change in your menstrual bleeding.
  • You have sex without using two forms of effective birth control.
  • You have unprotected sex with a man who takes these medicines.

If you get pregnant while taking thalidomide or lenalidomide, your provider must alert the company that makes the medicine and the Food and Drug Administration (also called FDA). The FDA is a government agency that checks the safety of medicine and food in this country. 

Are there programs to help prevent birth defects from these medicines?

Yes. Because these medicines can be so harmful to a developing baby, both women and men must register with the THALOMID REMS™ program or the REVLIMID REMS™ program before they can take them. These programs are approved by the FDA. 

Only doctors and pharmacists who are registered in these program can prescribe and give these medicines to their patients. Both men and women who take these medicines must agree to follow strict rules to help prevent pregnant women and women who may become pregnant from having contact with these medicines. 

Women taking these medicines must agree use two different forms of effective birth control and take regular pregnancy tests. They also must agree not to get pregnant:

  • For at least 4 weeks before they start using the medicines
  • While taking the medicines and during any breaks in treatment 
  • For at least 4 weeks after they stop using the medicines

Men who take these medicines can have them in their semen. During ejaculation, a man releases semen. Semen contains sperm. Experts don’t know if semen with thalidomide or lenalidomide can lead to birth defects. But to be safe, men taking these medicines must agree to use condoms anytime they have sex with a woman of childbearing age. 

What health conditions do these medicines treat?

Thalidomide may be used to treat health conditions including:

  • Crohn’s disease. This disease causes inflammation (swelling and redness) of the digestive system. It’s one of a group of diseases called inflammatory bowel disease or IBD. Thalidomide blocks substances that cause swelling.
  • Hansen’s disease (also called leprosy). This is an infection caused by bacteria that affects the skin, nerves and mucous membranes. Mucous membranes are the moist tissues that line certain parts of the inside of your body, like your nose, mouth and lungs. 
  • HIV complications. HIV stands for human immunodeficiency virus. It’s a virus that attacks the body’s immune system and causes AIDS. Thalidomide is used to treat HIV complications, like ulcers in the mouth, diarrhea and Kaposi’s sarcoma (a type of cancer that can involve the skin, mouth, intestines and other organs).
  • Multiple myeloma. This is a cancer of the bone marrow, the soft, fatty tissue inside your bones. Thalidomide makes the body’s immune system stronger to fight cancer cells.

Lenalidomide helps bone marrow make normal blood cells and kills abnormal cells in the bone marrow. It’s usually used to treat myelodysplastic syndrome (also called MDS), a group of conditions that happen when the bone marrow doesn’t make enough healthy blood cells. Lenalidomide also is sometimes used to treat multiple myeloma.


Last reviewed: May, 2014