The family of a pregnant woman who died while taking experimental AIDS (search) drugs to protect her baby from getting the disease is suing the doctors, drug makers and hospitals involved in the study for $10 million.

Joyce Ann Hafford's (search) mother and sister allege in the suit filed Tuesday that doctors continued to give Hafford the drug regimen despite signs of liver failure. The suit also claims doctors didn't warn the 33-year-old HIV-positive woman of the trial's dangers. The family is seeking $10 million in damages.

"She trusted doctors to treat her, and they failed her," said Rubbie King, Hafford's sister.

Family members said they did not learn the National Institutes of Health (search) had concluded the drug therapy most likely caused Hafford's death until The Associated Press obtained copies of the case file this month.

For the past year, family members believed Hafford died from AIDS complications.

NIH officials quickly suspected the drug regimen because it included nevirapine (search), an antiretroviral AIDS drug known to cause liver problems. Hafford's death in August 2003, less than 72 hours after her son Sterling was born prematurely, halted the federal government research program of nevirapine.

Hafford learned she was HIV-positive when she became pregnant in spring 2003, and shortly after started the NIH-funded clinical trial of the drugs Combivir and nevirapine, also known as Viramune, hoping to block transmission to her son.

The baby was born HIV-negative.

The family first filed a wrongful death suit in June, but withdrew it in September because lawyers felt they didn't have enough evidence.

Among the defendants named in the suit are several doctors and nurses who treated Hafford, the Regional Medical Center and drug makers GlaxoSmithKline and Boehringer Ingelheim Pharmaceuticals.

A message at British manufacturer GlaxoSmithKline's American offices said they were closed for the holidays. Boehringer Ingelheim is based in Germany.