CDC: Physicians should seek expert advice on PEP

CDC: Physicians should seek expert advice on PEP

New drugs add to complexity

Health care workers are more likely to receive post-exposure treatment after a bloodborne pathogen exposure than they were 10 years ago, but management of their regimens still needs improvement, according to the Centers for Disease Control and Prevention (CDC) in Atlanta.

With new drug choices, post-exposure prophylaxis (PEP) can result in fewer side effects, but the selection of the best regimen has become more complex. Prescribing physicians should seek out expert opinion, especially if the source patient has received long-term treatment for HIV infection, the CDC said in updated guidelines.¹

After 72 hours, physicians should follow up with the injured health care worker, review any new information about the exposure or the source patient, and consider altering the regimen, the guidelines say.

"The principles of occupational exposure management are essentially unchanged," explains Lisa Panlilio, MD, MPH, a CDC medical epidemiologist and an author of the guidelines. "You follow all the same steps in terms of assessing the risk of exposure and deciding whether or not what has happened really poses a threat of infection transmission. What’s really changed is the array of post-exposure prophylaxis regimens," she says.

Emergency department physicians may not be familiar with PEP drug choices, the CDC found in focus groups conducted in 2002.¹ Most (95%) of the 71 participants had not read the 2001 CDC guidelines on post-exposure prophylaxis, even though they had managed blood and body fluid exposures, the CDC found. Many hospitals have in-house expertise, such as infectious disease physicians who regularly treat HIV patients. But those that do not should seek consultation in the community or through the National Clinicians’ Post-Exposure Prophylaxis Hotline (PEPline), run by physicians with the National HIV/AIDS Clinicians’ Consultation Center at the University of California at San Francisco (UCSF), the CDC says.

Don’t delay PEP while you seek advice on the best drug combination, the CDC guidelines stress. "It appears that starting antiretroviral drugs very early on is key," says Ronald Goldschmidt, MD, director of PEPline and vice chair of the UCSF department of family and community medicine.

"By very early on, we really mean within hours of the exposure, certainly within 24 hours whenever possible. If adjustments in antiretroviral drugs have to be made later based on more information about the source patients’ virus, that can be done and there does not appear to be a problem in doing so."

Here are some issues to consider when managing post-exposure prophylaxis:

• Available drugs vary in toxicity.

Some 47% of health care workers experienced one or more symptoms from PEP, according to CDC surveillance. And studies show that 17% to 47% of health care workers failed to complete a four-week course of PEP because of side effects, the CDC reported. Newer and more effective drugs have become available that "have far fewer side effects than the drugs we were using earlier and are more convenient to take," says Goldschmidt.

Health care workers using older regimens should be reassured that they can receive medications to resolve the common side effects of nausea, diarrhea, and vomiting, says Panlilio.

• A two-drug regimen is sufficient for many occupational exposures.

"It has become quite common that treating clinicians have been putting exposed health care workers on [expanded regimens of] three drugs or four drugs routinely, no matter what the exposure," says Goldschmidt. "But as the guidelines once again point out, there is no evidence that [using] three and four drugs is more effective in preventing transmission in occupational exposures than is the basic two-drug regimen," he says. "So the guidelines once again reinforce that two-drug therapy is sufficient for many of the less high-risk exposures that occur so frequently."

For example, if the source patient has a known low viral load or has an asymptomatic HIV infection, the CDC recommends a two-drug regimen. Health care workers may be more likely to complete the two-drug regimen because of fewer side effects, notes Panlilio.

• Drug resistance makes the selection of appropriate PEP more difficult.

HIV source patients who have received long-term treatment present a different scenario because the virus may be resistant to some antiviral agents. In this case, the CDC recommends a regimen of three or more drugs and urges facilities to seek expert guidance. "Because of the complexity of selection of HIV PEP regimens, consultation with persons having expertise in antiretroviral therapy and HIV transmission is strongly recommended," the guidelines state.

That is especially true when source patients have had long-term treatment for HIV infection. "Even many of the very experienced emergency rooms and occupational health units call us because of questions about viral resistance," says Goldschmidt. The CDC noted the report of a seroconversion of a nurse performing phlebotomy on an HIV-infected patient who had failed treatment with several antiviral medications. The nurse was placed on a three-drug regimen but stopped one after eight days and the other two after 24 days due to side effects.

• All health care workers with occupational exposure to HIV should receive follow-up testing and counseling for at least six months.

HIV testing of exposed health care workers should occur at the time of exposure and six weeks, 12 weeks, and six months after the event. However, the guidelines recommend a broader view of follow-up care that includes counseling and management of adverse effects of PEP. Even if no PEP is prescribed after an exposure from a source patient of unknown HIV status, the health care worker may need additional reassurance, says Panlilio. "This is a very stressful event," she says. "Workers will benefit from counseling whether or not they take post-exposure prophylaxis."

The CDC advises exposed health care workers to avoid blood or tissue donation, breastfeeding or pregnancy, "especially during the first six to 12 weeks post-exposure." Goldschmidt also advises exposed health care workers not to have unprotected sex with their partners during the first three months after exposure.