ALSO U.S. issues warning on one use of anti-AIDS drug Lactic acidosis is a condition that occurs when cells are unable to convert food into usable energy.
Excess acid accumulates in the body and can damage organs like the liver or pancreas.
Lactic acidosis is a known side effect to some anti-HIV drugs. The FDA said it has received several reports of non-fatal lactic acidosis in pregnant women who were only taking the two drugs. Although data have suggested that women may be at increased risk for the development of lactic acidosis and liver toxicity, it is unclear whether pregnancy exacerbates the drugs' side effects. The drug company sent a warning letter to health professionals Friday, saying the combination of the two drugs should only be prescribed for pregnant women when the benefit clearly outweighs the risk, for instance, when a woman has exhausted all other treatment options. Pages will open in a new browser window External sites are not endorsed by CNN Interactive.