Birth Defect in Baby Born to Efavirenz User

The non-nuke efavirenz (Sustiva, Stocrin) is used as part of combination therapy by some people with HIV/AIDS (PHAs). Efavirenz can cause the following commonly experienced side effects:

• rash
• confusion
• dizziness
• difficulty concentrating
• drowsiness during the day
• difficulty falling asleep at night
• intense dreams and/or nightmares

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:

• 34 years old
• 390 CD4+ cells
• a viral load of 7,600 copies

Doctors prescribed standard doses of the following drugs:

• AZT (Retrovir)
• d4T (stavudine, Zerit)
• efavirenz

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:

• 3TC (lamivudine, Epivir)
• d4T
• nelfinavir (Viracept)

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:

• First, the baby had a large mass outside its body near the base of its spine, a condition called myelomeningocele.
• Second, the flow of fluid in the baby's brain/spinal cord was blocked.

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.

Does Efavirenz Cause Birth Defects in People?

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.

References

1. Fundaró C., Genovese O., Rendeli C., et al. Myelomeningocele in a child with interuterine exposure to efavirenz. AIDS 2002; 16(2):299-300.
2. Botto L. D., Moore C. A., Khoury M. J. and Erickson J. D. Neural tube defects. New England Journal of Medicine 1999; 341(20):1509.1519.