Health Canada, Canada’s health regulatory agency, warns that the organ anti-rejection drugs CellCept (mycophenolate mofetil) and Myfortic (mycophenolate sodium) can cause miscarriage and congenital malformations following exposure during pregnancy.
The agency warns about use of the drugs:
- during pregnancy due to their mutagenic (changing the DNA) and teratogenic (interfering with the development of the fetus) potential
- by women of childbearing potential who are not using highly effective contraceptive methods
- by women who are breastfeeding because of the potential for the drugs to cause genetic mutations
Congenital malformations-sometimes multiple-have been reported in children of patients exposed to mycophenolate mofetil in combination with other immunosuppressants during pregnancy.
The following malformations were most frequently reported:
- facial malformations such as cleft lip, cleft palate, undersized jaw, increased distance between the eyes;
- abnormalities of the ears and eyes;
- malformations of the fingers;
- cardiac abnormalities such as atrial and ventricular septal defects;
- esophageal malformations;
- nervous system malformations (such as spina bifida).
CellCept is given to prevent organ rejection in adult patients who have received kidney, heart, or liver transplants. CellCept is also prescribed for pediatric patients (2 to 18 years of age) who have received kidney transplants. Myfortic is prescribed for kidney transplant patients. These drugs are administered in combination with cyclosporine and corticosteroids.
Health Canada says that health care professionals should ensure that women and men taking mycophenolate drugs understand the risk of harm to the baby, the need for effective contraception, and the need to immediately consult a physician if there is a possibility of pregnancy.
Health Canada said a cumulative review of birth defects has confirmed that mycophenolate is a human teratogen (i.e., causes birth defects). The evidence showed an increased rate of congenital malformations and miscarriages associated with mycophenolate in comparison with other immunosuppressants.
Based on evidence from medical literature, Health Canada says, malformations occurred in 23 to 27 percent of live births in women exposed to mycophenolate mofetil during pregnancy, compared to 2 to 3 percent of live births in the overall population and approximately 4 to 5 percent in organ transplant patients treated with immunosuppressants other than mycophenolate mofetil. Cases of spontaneous abortions (miscarriage) have been reported in 45 to 49 percent of patients exposed to mycophenolate mofetil during pregnancy, compared to a reported rate between 12 and 33 percent in organ transplant patients treated with other immunosuppressants.
Health Canada says that women and men taking either of these CellCept or Myfortic should understand the risk of harm to the baby, the need for effective contraception, and the need to immediately consult a doctor if there is the possibility of a pregnancy. Patients of reproductive potential should be made aware of the increased risk of pregnancy loss and congenital malformations and must be counseled about pregnancy prevention, and planning.
The agency advises women who could become pregnant to use two reliable forms of contraception simultaneously before they begin to take mycophenolate, during mycophenolate therapy, and for six weeks following discontinuation of therapy, unless abstinence is their method of contraception.