A federal judge yesterday refused to require the Defense Department to get troops' consent before it uses investigational new drugs to counteract possible effects of nerve gas and biological warfare in the Persian Gulf region.

The order, signed by U.S. District Judge Stanley S. Harris, comes in response to a lawsuit filed earlier this month by lawyers for Public Citizen on behalf of an anonymous serviceman in Operation Desert Storm.

"The DOD's decision to use unapproved drugs is precisely the type of military decision that courts have repeatedly refused to second-guess," Harris's order said.

If military personnel refused their consent, it could affect strategic decisions about who is sent into combat, he wrote, and if troops went into combat without taking the drugs and were exposed to chemical or biological warfare, caring for them could distract their fellow soldiers.

Mike Tanskersley, an attorney with Public Citizen, said yesterday that his group planned to appeal. Sid Wolfe, director of Public Citizen's Health Research Group, said that allowing the ruling to stand would allow the military "to treat soldiers as though they are human guinea pigs."

The Pentagon got special permission from the Food and Drug Administration in December to waive a rule requiring patients' consent before they are given a drug still under investigation.

The lawsuit charged that the Defense Department was violating FDA rules and troops' constitutional rights by not informing them about the possible side effects of the drugs.

The drugs at issue are pyridostigmine tablets, butulinum vaccine and a topical cream called "multi-shield cream."

Because troops are given the drugs before they go into combat, the lawsuit alleged, there was no reason they could not be told of possible side effects, which include nausea, muscle cramps and weakness.