hirty Nigerian families sued Pfizer (news/quote) in federal court yesterday, saying the company conducted an unethical clinical trial of an antibiotic on their children in 1996. It is the first suit in the United States seeking damages from an American pharmaceutical company for what the plaintiffs say was medical experimentation on foreign citizens without their consent.

During a meningitis epidemic in 1996, Pfizer treated 100 Nigerian children with the antibiotic Trovan as part of its effort to determine whether the drug, which had never been tested in children, would be an effective treatment for the disease. Pfizer treated 100 other children with ceftriaxone, the gold standard for meningitis treatment, but, the suit says, at a lower-than- recommended dose. Eleven children in the trial died, and others suffered brain damage, were partly paralyzed or became deaf.

Vanessa McGowan, a spokeswoman for Pfizer, said yesterday that the company had not yet seen the suit, which was filed in Federal District Court in Manhattan, and could not comment on the allegations. In the past, Pfizer has said that the number of deaths in the Nigerian Trovan trial was lower than the overall fatality rate for the meningitis epidemic and that the trial had been a philanthropic effort that benefited most of the sick children, not a self-serving effort to obtain quick clinical data, as the suit contends.

In early 1996, within weeks of learning about the meningitis epidemic from an Internet site, Pfizer, the world's largest pharmaceutical company, sent a six-member research team to the Infectious Disease Hospital in Kano, Nigeria, a strife- torn city suffering concurrent epidemics of bacterial meningitis, measles and cholera. The Pfizer team selected children for its test from the long lines of ailing people seeking care at the hospital.

"Pfizer took the opportunity presented by the chaos caused by the civil and medical crises in Kano to accomplish what the company could not do elsewhere — to quickly conduct on young children a test of the potentially dangerous antibiotic Trovan," said the suit, which was filed yesterday by Milberg Weiss Bershad Hynes & Lerach, a New York law firm that specializes in representing groups of plaintiffs against large corporations.

Pfizer conducted the trial at the same hospital where Doctors Without Borders, the Nobel Prize-winning relief organization, was already providing free treatment with chloramphenicol, the cheaper antibiotic that is internationally recommended for treating bacterial meningitis.

"Rather than provide the children with a safe, effective and proven therapy for bacterial meningitis," the suit said, "Pfizer chose to select children to participate in a medical experiment of a new, untested and unproven drug without first obtaining their informed consent, or explaining to the children or their parents that the proposed treatment was experimental and that they were free to refuse it and instead choose the safe, effective treatment for bacterial meningitis offered at the same site, free of charge, by a charitable medical group."

Under the Nuremberg Code of 1947 and the World Medical Associations Declaration of Helsinki, those seeking to conduct medical tests on human subjects must explain the purpose, risks and methods of the study and obtain each subject's voluntary consent to participate.

Elaine Kusel, a Milberg Weiss lawyer who visited Nigeria this spring to investigate the case, said many of the parents told her they had had no idea they were taking part in a test of an experimental drug.

"The families involved understood the Pfizer was providing their children with volunteer relief, not that their children were `being volunteered' to help Pfizer," the lawsuit said.

The suit, brought under the Alien Tort Claims Act, seeks damages and continuing medical care for those in the study, along with an order enjoining Pfizer from conducting illegal human experimentation anywhere in the world.

According to the suit and earlier reporting on the Trovan trial by The Washington Post (news/quote), Pfizer never received the necessary approvals to conduct the research, but, when faced with an audit of its Trovan records by the Food and Drug Administration in 1997, the company produced a letter dated March 28, 1996, from the hospital saying the Trovan study had been approved by the hospital's ethics committee.

But the suit contends that letter was written a year later and backdated — and that at the time the Pfizer trial took place, the hospital had neither an ethics committee nor the letterhead on which that letter was written.

Pfizer also violated international law, the lawsuit says, by failing to inform the families that alternative treatment was available from Doctors Without Borders, failing to perform the necessary diagnostic tests to ensure that the children selected in fact had bacterial meningitis, failing to modify treatment for children who did not improve after initial drug therapy and failing to provide follow-up treatment

The lawsuit said that Dr. Juan Walterspiel, a Pfizer infectious disease specialist assigned to the Trovan test, repeatedly told Pfizer management that the company was violating international law, federal regulations and medical ethics standards. Dr. Walterspiel was subsequently dismissed.

Pfizer already faces two class-action lawsuits and a government investigation in Nigeria.

And earlier this month in Washington, the House International Relations Committee approved an amendment to the pending Export Administration Act that would bar United States researchers from shipping experimental medicine to developing nations until they provide American regulators with the details of their plans and submit proof that a United States ethics committee has approved them.

When it was developed in the mid- 1990's, trovafloxacin mesylate, or Trovan, was expected to be an important new product for Pfizer, generating an additional $1 billion a year in sales if approved by the F.D.A. for all its potential uses. So beginning in 1996, Pfizer conducted the largest testing program every undertaken, enrolling thousands of people worldwide in clinical tests.

Trovan went on the market in 1998 and quickly became one of the most prescribed antibiotics in the United States, selling more than $160 million the first year. But there were soon reports of liver damage, and the F.D.A. recommended in 1999 that Trovan be used only for severely ill patients in institutional settings. Use on children has not been approved.

Pfizer has a mixed record of philanthropy in Africa. The company has been widely praised for its donation of millions of doses of Zithromax to treat trachoma, a common cause of blindness. But Pfizer's donation of Diflucan to South Africa, to treat some AIDS-related infections, has left the company open to criticism from those who say Pfizer put too many restrictions on how the free drugs are to be used and has a moral obligation to lower the price of the drug over all.