February 6, 2002
These side effects are supposed to fade during the first four weeks of use.
Efavirenz can also have other effects. In one series of experiments, researchers gave monkeys efavirenz throughout pregnancy. They found that three of 20 (15%) of the monkeys had fetuses which had various defects. Based on these results, the use of efavirenz is not recommended for women who are pregnant.
Doctors in Rome, Italy, recently reported a case of an HIV positive woman who gave birth to a baby with birth defects. The woman had the following profile before she became pregnant:
The doctors also counselled her about the potential risks of this therapy in women of childbearing age and advised her about the use of "adequate" birth control. Sometime later, she noticed that her periods had stopped. After performing a pregnancy test, she found that she was pregnant.
On reporting her findings to her doctors, they switched her therapy to the following regimen which is considered to be less toxic to the fetus:
Both before and during her pregnancy, the woman took the B-vitamin folic acid (folate). This vitamin can help reduce the risk of some birth defects. Nonetheless she gave birth to a baby with several defects:
Ordinarily, babies with these problems can die, but thanks to surgery, the myelomeningocele was removed and a shunt was placed in the brain to drain excess fluid. High-tech testing -- called PCR -- of the baby's blood suggested that it was not infected with HIV.
This report from the Italian doctors may well be the first case of a birth defect in a fetus accidentally exposed to efavirenz. It does not prove that efavirenz caused this type of birth defect, called a neural tube defect. The report does underscore the need for clear discussion and counselling by doctors about the potential risks and benefits of efavirenz to their HIV positive female patients who may become pregnant. If additional reports of neural tube defects in babies born to female users of efavirenz occur, then further and stronger precautions may be needed.