NEWS RELEASE, 11/24/98 Not a "morning-after" pill, but UC researchers recommend drugs to prevent AIDS after some exposures

By Kathleen Scalise, Public Affairs

BERKELEY -- Immediate preventative treatment to ward off AIDS following possible exposure to HIV through sex or injection drug use is warranted under certain conditions, reports a University of California, Berkeley, researcher and her collaborators in the Nov. 25 Journal of the American Medical Association. Such "prophylactic" treatment is already recommended by the Centers for Disease Control and Prevention, but only for doctors, nurses and other medical professionals after accidental exposure to infected body fluids on the job. In one study of health care workers exposed to HIV-infected blood, AZT use was associated with a 79 percent reduction in infection. "We're applying this recommendation in certain situations to the much more frequent modes of HIV transmission, intravenous drug use and sexual transmission," said UC Berkeley Associate Field Research Supervisor Suellen Miller, PhD, CNM, a public health faculty member and co-author on the research paper, which appears in this week's issue of JAMA (11/25/98). To substantiate these recommendations, the researchers present risk data in their paper and analyze the economics of treatment. "A non-infected person who practices safer sex with their HIV-positive mate and is accidentally exposed through condom breakage should be considered for prophylactic treatment in the same way as health care workers suffering a needlestick injury," Miller said. "It is ethically mandatory that all persons who receive similar exposures should receive similar treatment." Her co-authors from the University of California San Francisco are Dr. Peter Lurie and Margaret Chesney, PhD, both of the Center for AIDS Prevention Studies; Prof. Frederick Hecht, Department of Medicine, AIDS Program; and Dr. Bernard Lo, Program in Medical Ethics. Unlike the one-shot "morning-after" pill for post-coital birth control, prophylactic AIDS prevention consists of a rigorous and expensive month-long course of drugs, often including protease inhibitors and AZT. It should be started not later than 72 hours after exposure. "We are suggesting treatment scenarios similar to what survivors of sexual assault receive, who currently go to the emergency room and may be offered preventative treatment for other sexually transmitted diseases and even pregnancy, depending on risk factors," said Miller. She said the biggest fear in the public health community - and probably the biggest objection that will be raised to the proposal - is the risk of developing resistance, both in the patient, should HIV be contracted, and in the community, where resistant strains could wreak havoc with present treatment strategies. "These are potent drugs and they also require rigorous treatment regimens," she said. Although there is no data on the effectiveness of prophylactic treatment in non-occupational settings, the authors provide epidemiological guidelines and clinical cases to assist clinicians in making the difficult decision of whether to treat. "Although providing prophylactics to patients with appropriate non-occupational exposures to HIV is important, we need to monitor the impact on community levels of HIV risk behavior," said Lurie. "Our analysis shows that, even under assumptions favorable for treatment, a mere 10 percent increase in risk behaviors can obliterate any benefit that might come from treatment." Side effects of the drugs vary from one individual to the next, but can include all problems associated with current treatments of AIDS patients using the protease/AZT drug combinations, such as nausea and fatigue. Miller points out that not every exposure to HIV would call for prophylactic treatment. The JAMA paper recommends that physicians look at the prevalence of HIV in their community and the method of exposure before making the decision on treatment. "This is recommended only for sporadic exposure. People who have an ongoing exposure," such as regular sex without the use of condoms, "really need to address that problem with primary prevention measures, such as abstinence, monogamy or consistent and correct condom use," she said. The cost of prophylactic treatment could exceed $1,000 per exposure episode, with drug costs ranging from $500 to $1,000 and requisite physician and office visits running between $500 and $600. The researchers are optimistic that insurance plans will cover such treatment in situations when the risk of infection is comparable to that experienced by medical personnel following HIV occupational exposure.