Peter* had unprotected sex with a group of guys during a Pride party this year. HIV-negative, he woke up the next morning terrified about HIV infection. Peter immediately contacted his doctor, Anthony Urbina, MD, because he knew something a lot of sexually active men don’t: If he had been exposed to HIV, he might be able to stave off infection by taking post-exposure prophylaxis (PEP)-a 28-day regimen of HIV medications started immediately after the encounter.

While not 100 percent effective, PEP has been recommended by the Centers for Disease Control and Prevention (CDC) for healthcare providers who are accidentally exposed to HIV infected blood on the job. That’s what happened to John*, a colorectal surgeon in New York City who got stuck with a bloody needle while operating on a patient with HIV.

"It was emotionally traumatic, especially since I had to continue the surgery after the needle stick," he recalls. Once out of the operating room, John spoke with someone at the CDC’s PEP Hotline and conferred with a couple of HIV specialists. Everyone agreed he should begin PEP immediately. For John, fear of HIV infection outweighed any worries he might have had about physical side effects of the medications. "The drugs made me queasy, but I was emotionally a wreck to begin with." Luckily, he escaped infection.

After his own experience, John says he doesn’t hesitate to offer an immediate referral to an HIV specialist when patients inquire about PEP. He doesn’t feel he has the expertise to prescribe it himself but thinks it’s an important option for people. "It should not be used as an alternative to safer sex," he says. "But accidents-and mistakes-do happen."

Unfortunately, many people who fear they’ve been exposed to HIV will never ask their doctor about PEP for the simple reason that many of them have never heard of it. Most healthcare providers-even many with practices that cater to people at high risk of HIV infection-never discuss it with their patients. One reason they don’t is because the CDC has never released recommendations for the use of PEP in cases of non-occupational exposure. Likewise, the CDC’s PEP Hotline (run by the University of San Francisco) is not prepared to counsel people about sexual exposures.

The lack of guidelines for exposures to people outside the medical community can only be regarded as a glaring omission on the CDC’s part, given that, after years of stability, rates of HIV infection in the U.S. are once again belived to be inching up-especially among gay and bisexual men. After all, the CDC’s own estimates put the risk of infection from unprotected receptive sex at up to 3 percent. The risk for a percutaneous needle stick? Around 0.3 percent.

According to Lisa Grohskopf, a medical epidemiologist at the CDC, the organization is currently finalizing its first-ever recommendations for non-occupational PEP. At press time, however, she could offer no information as to what the recommendations would be or when they might be released.

In the meantime, healthcare providers and patients are left to decide for themselves when to use PEP, a challenge considering the lack of awareness about the regimen, even from within the medical community.

In an effort to assess how far PEP is below the radar of health professionals, Urbina, who works at St. Vincent’s Medical Center in New York City, once
called the emergency room posing as a patient. After explaining that he might have been exposed to HIV during risky sex, he asked about PEP. "They put me on hold for about twenty minutes," he says. "Finally, a very irate gynecologist picked up the phone and said, ‘Sir, we don’t do emergency pap smears!’ I don’t think a lot of physicians are on board with PEP."

The lack of CDC recommendations may only be part of the reason why. For starters, Urbina thinks many in the medical community don’t want to be bothered with calls from the types of patients they feel are going to be requesting PEP-gay men, people with multiple partners, people with substance-abuse problems. Providers may also be concerned that if people know PEP is available, some will take it as license to have unsafe sex. People who oppose the use of emergency contraception-a high-dose of hormones that, if taken by a woman within 72 hours of unprotected intercourse, prevents pregnancy-have used the same argument to discourage use of the so-called "morning-after pill" for decades.

"But this isn’t the morning-after pill," Urbina points outs. "It’s the 28-days-after pill. Small studies have shown that even when PEP is offered, patient requests for it won’t increase.

"Physicians may also be reluctant to prescribe a month of HIV medications when there is no guarantee that PEP will work. Susan C. Ball, MD, MPH, assistant director of the Birnbaum Unit HIV Care Center at New York Presbyterian Hospital, recalls the case of a nurse who went on PEP within two hours of exposure. She took the medications as directed, but nonetheless tested positive at the end of the regimen.

"PEP really is an unproven intervention," says the CDC’s Grohskopf. While there’s been a small study of PEP for occupational exposures from needle sticks (which indicated that PEP might reduce the risk of HIV infection by about 81 percent), no studies have been done to date regarding the efficacy of PEP for non-occupational exposures. But we may never have definitive answers about how effective PEP is-for any type of exposure. The trials that are commonly performed when new drugs are being tested-where half of the participants get the drug and half take a placebo (a drug-free sugarpill)-would, in the case of PEP, according to Grohskopf, be "not practical and possibly not ethical."

Urbina says that the lack of firm data is no reason to withhold PEP from people with possible sexual exposure to HIV. He believes there is enough evidence-both anecdotally and from occupational exposures-to suggest that PEP is, in most cases, effective. "But people shouldn’t have this misconception that this is something that will always be effective."

So if you think you may have been exposed to HIV, should you take PEP? There is no simple answer. It all depends on the particular circumstances involved. The following are some important considerations for you to discuss with your doctor.

PEP Hotline for occupational exposures at 888-448-4911 for basic information. Either that or call the nearest big-city emergency room or HIV clinic to find soemone who can help.

Given the small window of time to start PEP, Urbina encourages people to discuss PEP-and sexual health, in general-with their doctor before a crisis arises. "When a PEP call comes, doctors really need to be as calm, nonjudgmental, and clinical as possible," he says.

WAS THE ENCOUNTER RISKY ENOUGH TO JUSTIFY THE USE OF PEP?
Evaluating the risk of sexual exposure has to be done on a case-by-case basis. It’s much easier to gauge the risk in occupational settings because in most cases a healthcare provider knows if the blood he’s been exposed to carries HIV. With sex, whether there actually has been exposure to the virus-whether your partner was HIV-positive-is often unknown, so the details of the sexual encounter itself become the primary basis for determining risk.

A 1998 report from the CDC on non-occupational exposures suggested PEP should be restricted to only the most high-risk scenarios-for example, unprotected receptive anal or vaginal sex with a partner known to have HIV. But factors such as bleeding gums or sores or cuts in the mouth or on the penis could certainly make oral sex or unprotected insertive anal sex high-risk.

WHAT HIV MEDICATIONS SHOULD PEP INCLUDE?
Even for occupational exposures, there are different opinions about what HIV drug or drugs to take. Most doctors believe that a combination of drugs is most likely to be effective. If you know the person you were having sex with is HIV positive, his treatment history may affect the drugs your doctor selects. Drugs that haven’t worked for him will be unlikely to work for you. Any information you can get-a drug resistance profile, for example, or just a list of HIV meds he’s taking or taken-will help your doctor make the best choices.

UNDERGOING TREATMENT
DOES INSURANCE COVER PEP?
Both private insurers and Medicaid cover PEP, says Urbina, and there is a diagnosis code for exposure to HIV. If you don’t have insurance, physicians often have reserves of antivirals on hand. Discuss access with your doctor.

IS THERE A RISK OF DEVELOPING DRUG RESISTANCE?
If PEP is unsuccessful, and you haven’t carefully followed the dosing schedule, there is a theoretical risk of you being infected with HIV that is already resistant to one or more of the drugs you were taking, limiting your treatment options.

ARE YOU EXPERIENCING SIDE EFFECTS?
Side effects such as nausea, diarrhea and fatigue are fairly common with many antiretroviral medications, says Grohskopf. While you’re taking PEP, you need to stay in contact with your doctor and tell him about any side effects you are experiencing. While most will only be annoying, some can actually be quite serious, and in some cases life-threatening. That’s why it’s a good idea to have bloodwork done several times during the month you’re on PEP to help spot dangerous side effects.


AFTER TREATMENT
DID TREATMENT WORK?
Take an HIV test after you’ve completed PEP to see if treatment was successful. If your result is negative, get a second test six months later to confirm.

IS ANOTHER EXPOSURE LIKELY?
One of the most difficult decisions for health providers is whether PEP should be given to the same patient repeatedly. From a strictly medical standpoint, you can go on PEP numerous times, although some doctors do worry about the toxicity of the medications. Urbina gave one man PEP four times in two years, but he points out the patient was in the midst of battling a drug addiction, which he has since gotten help for.

WHAT CAN YOU DO TO AVOID ANOTHER EXPOSURE?
First, talk to your doctor. "Physicians counsel people to stop smoking and diminish their alcohol use," says Grohskopf. "If someone is having repeated exposures, it’s probably a good time to discuss ways to diminish the likelihood of this happening again, because the medicines are not to be taken lightly."

Ball agrees that it’s necessary for doctors to discuss behavior with their patients. "If PEP is really going to be effective, you can’t expect to go on it for four weeks, and then have unsafe sex and go on it again," she says. "That just doesn’t make sense."

Counseling may help people from repeating mistakes, but Urbina fears many physicians are not adept at counseling patients about sexual risk-taking. He himself prefers to have patients with a propensity for carelessness see a social worker or therapist who can focus on the psychological and behavioral aspects of sexual exposure.

Safer sex should always be your first defense against HIV. A time may come, however, when PEP may be your last, best chance to prevent HIV infection. It’s going to be up to you to know your options.

"I don’t think the federal government or your local health department is going to drive this," says Urbina. "We may never have direct evidence about how effective PEP is, but in no way does that mean you should be denied it."

*Names have been changed