AIDS-Exposed Lab Workers to Get AZT Drug

In a highly unusual action that sanctions an unproved use of the AIDS drug AZT, the National Institutes of Health--the research arm of the federal government--has recommended that its employees who have suffered “significant” exposure to the AIDS virus be given the drug even before an infection is detected, The Times has learned.

AZT, although it has been approved for marketing, has not yet been recommended for individuals who have been exposed to the virus but have not yet been shown to be infected. Further, it has not even been studied in humans under those conditions, although several studies in animals have suggested that the early use of AZT--or zidovudine--sometimes may prevent the onset of infection after exposure.

In a safety notice delivered Thursday to all of its employees who work in AIDS laboratories on the NIH campus in Bethesda, Md., the agency acknowledged that “definitive evidence for the efficacy (in these circumstances) has yet to be established.” Nevertheless, it recommended that “administration of AZT should be initiated as soon as possible, preferably within hours following the exposure.

“The offer to provide AZT as a prophylactic measure will occur in those cases where it is judged that the individual may have sustained a significant exposure,” the notice said. This will be determined by the nature of the exposure and the conditions under which it occurred, the agency said. The danger to research workers typically exists when an injury--such as a needle-stick accident--occurs.

Typically, AIDS researchers work directly with highly concentrated amounts of the virus and thus are potentially in greater danger of infection.

The NIH decision signals yet another move to endorse the use of certain AIDS drugs before the traditional scientific procedures have been followed. Recently, for example, the Food and Drug Administration approved the wider distribution of aerosol pentamidine, an experimental drug that has been shown to prevent the onset of deadly pneumocystis carinii pneumonia in AIDS patients, before the research was completed.

‘Makes Abundant Sense’

The NIH decision was reached in consultation with an advisory group of prominent AIDS researchers, NIH sources said. The announcement will likely result in most facilities in the nation doing AIDS work establishing the same policy; in fact, many are quietly already doing so.

“I believe the policy is rational, and it’s what I would have done without them telling me anyway, if I could get my hands on the drug,” said Dr. Robert Gallo, a co-discoverer of the AIDS virus, who directs a team of AIDS researchers at the National Cancer Institute, which is part of NIH.

“I believe that any potent drug which blocks viral replication--like AZT--can limit the infection,” he added. “If you can get the therapy within the hour, you could block perhaps the earliest infection. It makes abundant sense.”

Nevertheless, the policy decision is likely to evoke some criticism, since studies of AZT on humans--which are being sponsored by the NIH--are under way nationwide among a large group of infected individuals, most of them gay men, who have not yet developed symptoms of AIDS. These clinical studies involve using an equal number of individuals as “controls” who do not receive the drug but are given a medically worthless placebo. Federal health officials have insisted that such trials are necessary to provide important scientific answers.

Already Prescribed

But it is also widely known that, despite the studies, many physicians already prescribe AZT for their patients who are infected but who have not yet developed symptoms of the disease.

One NIH source defended the agency decision to administer AZT to its workers, saying: “There may be a tiny little window where maybe you can stop infection. This is something you should do.”

But Rep. Henry A. Waxman (D-Los Angeles), chairman of the House Energy and Commerce subcommittee on health, questioned the ethics of the NIH decision.

Also Raises Dilemma

“This may be a perfectly valid medical decision, but if the people at NIH think it is valid for their health care workers, then it should be valid for ordinary people who have been exposed to the virus as well,” he said. “This also raises the dilemma of whether they will ever be able to get a placebo-controlled clinical trial to know if AZT really is effective in stopping the infection.”

AZT’s manufacturer, Burroughs Wellcome, is conducting a placebo-controlled nationwide study of AZT in health care workers exposed to the virus. The company has experienced difficulty recruiting volunteers, however, and is considering dropping the study, NIH sources said.

AZT is the only drug approved to treat AIDS patients, but it has thus far been proven valuable only for those who have suffered clear symptoms of the disease, specifically the life-threatening pneumocystis carinii pneumonia, or the condition known as AIDS-related complex (ARC). It is believed to block the ability of the AIDS virus to reproduce.

AZT has some known toxic side effects, including lowering the level of both white and red blood cells.