Hiv prevention (PEP) (TREATMENT AFTER EXPOSURE)
Sep 18, 2008
I recently had sex with a man i do not know, without my knowledge he removed the condom. I went to the Er and was prescribed Viread and combavir, will this lower my chances of contracting Hiv?
Response from Dr. Frascino
Yes, PEP, if appropriately prescribed and taken, can decrease the chance of infection following an HIV exposure. PEP is most effective when started as soon as possible (and no later than 72 hours) after an exposure. I'll reprint some information below from the archives about PEP.
Treatment After Exposure to HIV
August 24, 2007
What Is Post-Exposure Prophylaxis? Who Should Use PEP? Should PEP Be Used for Non-Occupational Exposure? How Is PEP Taken? What Are the Side Effects? The Bottom Line For More Information
What Is Post-Exposure Prophylaxis? Prophylaxis means disease prevention. Post-exposure prophylaxis (or PEP) means taking antiretroviral medications (ARVs) as soon as possible after exposure to HIV, so that the exposure will not result in HIV infection. These medications are only available with a prescription. PEP should begin as soon as possible after exposure to HIV, but certainly within 72 hours. Treatment with 2 or 3 ARVs should continue for 4 weeks, if tolerated.
Who Should Use PEP? Workplace Exposure PEP has been standard procedure since 1996 for healthcare workers exposed to HIV. Workers start taking medications within a few hours of exposure. Usually the exposure is from a "needle stick," when a health care worker accidentally gets jabbed with a needle containing HIV-infected blood. PEP reduced the rate of HIV infection from workplace exposures by 79%. However, some health care workers who take PEP still get HIV infection. Other Exposure In 2005, the Centers for Disease Control reviewed information on PEP. They concluded that it should also be available for use after HIV exposures that are not work-related. People can be exposed to HIV during unsafe sexual activity, when a condom breaks during sex, or if they share needles for injecting drugs. Infants can be exposed if they drink breast milk from an infected woman. In a study of PEP in 400 cases of possible sexual exposure to HIV, not one person became infected with HIV.
Should PEP Be Used for Non-Occupational Exposure? HIV exposure at work is usually a one-time accident. Other HIV exposures may be due to unsafe behaviors that can occur many times. Some people think that PEP might encourage this unsafe behavior if people think that PEP is an easy way to avoid HIV infection. There are other reasons why PEP might not be a good idea for non-occupational exposure:
There is no research to show that PEP works for non-occupational exposure. We don't know how soon after exposure to HIV someone has to start PEP.
PEP is not a "morning-after pill." It is a program of several drugs, several times each day, for at least 30 days. PEP costs between $600 and $1,000.
For best results, you have to take every dose of every PEP medication. Missing doses could mean that you develop HIV infection. It could also allow the virus to develop resistance to the medications. If that happens they would no longer work for you.
The medications have serious side effects. About 40% of health care workers did not complete PEP because of the side effects. Despite these concerns, there is growing interest in PEP for non-occupational exposure. Most programs include counseling to inform and encourage people to avoid exposure to HIV.
How Is PEP Taken? PEP should be started as soon as possible after exposure to HIV. The medications used in PEP depend on the exposure to HIV. The following situations are considered serious exposure:
Exposure to a large amount of blood; Blood came in contact with cuts or open sores on the skin; Blood was visible on a needle that stuck someone; and Exposure to blood from someone who has a high viral load (a large amount of virus in the blood). For serious exposures, the U.S. Public Health Service recommends using a combination of three approved ARVs for four weeks. For less serious exposure, the guidelines recommend four weeks of treatment with two drugs: AZT and 3TC.
In January 2001, the Centers for Disease Control warned against using nevirapine for PEP because of the risk of liver damage. See Fact Sheet 431 for more information on nevirapine. The CDC has updated its PEP recommendations in September of 2005.
What Are the Side Effects? The most common side effects from PEP medications are nausea and generally not feeling well. Other possible side effects include headaches, fatigue, vomiting and diarrhea. For more information, see the fact sheets on individual ARVs.
The Bottom Line Post-exposure prophylaxis (PEP) is the use of ARVs as soon as possible after exposure to HIV, to prevent HIV infection. PEP can reduce the rate of infection in health care workers exposed to HIV by 79%. The benefits of PEP for non-occupational exposure have not been proven. This use of PEP is controversial because some people fear it will encourage unsafe behaviors.
PEP is a four-week program of two or three ARVs, several times a day. The medications have serious side effects that can make it difficult to finish the program. PEP is not 100% effective; it cannot guarantee that exposure to HIV will not become a case of HIV infection.
For More Information CDC guidelines on PEP are on the Internet. Occupational exposure: www.thebody.com/cdc/pdfs/rr5011.pdf
Non-occupational exposure: www.cdc.gov/mmwr/preview/mmwrhtml/rr5402a1.htm
Before and After: PrEP and PEP
By Luis Scaccabarozzi and Mark Milano
One of the more surprising discoveries of the last decade was that HIV meds could not only treat HIV infection, but also prevent it. Using these drugs soon after exposure to HIV has become an accepted practice, but using them before exposure remains controversial. Here's what we know about both of these approaches.
PEP PEP, short for post-exposure prophylaxis, was first shown to be effective in preventing occupational exposure to HIV (needlesticks and blood splashes, etc.). This led researchers to study whether giving HIV meds shortly after sexual exposure might also work. But since the drugs used are all FDA-approved and available by prescription, it was not considered ethical to conduct controlled studies (in which half the participants get drug and half get a placebo, or dummy pill). So the only studies done have given meds to everyone in the study -- a useful source of data, but not a method that can conclusively prove whether this approach works. Still, results have been impressive: of 401 people treated in a PEP study in San Francisco in the late '90s, none seroconverted.
How Does It Work? Timing is critical when it comes to PEP. HIV meds must be started as soon as possible (recommendations vary from 36 to 72 hours after exposure), and continued for 28 days. The effectiveness decreases the longer treatment is delayed, so starting quickly is important. In many states, every organization working with people with HIV is required to have a policy in place to deal with occupational exposures so that employees don't have to scramble to find out what to do after an exposure occurs. People should know where to go for care before an exposure happens. If you're exposed in the middle of the night, don't wait until morning to call your doctor -- go to the nearest ER as soon as possible and take that first dose!
Before starting PEP, a provider must determine that:
The exposure occurred within the preceding 72 hours (NYS DOH recommends 36 hours). The patient is HIV negative (a new HIV antibody test is recommended before starting PEP). It is known, or there is a good chance, that the source individual has HIV. There was a significant risk of exposure (PEP is usually used only for occupational exposures or for vaginal or anal intercourse without a condom, but each case is considered individually). If it's possible to interview the source individual, a regimen will be chosen based on that person's treatment history and any known drug resistance. For women, interactions with birth control meds and the possibility of pregnancy will be taken into account. Generally, triple combination therapy (the same kind used to treat HIV infection) is used.
Sticking to It PEP is not a picnic. Side effects to HIV meds are often strongest in the first few weeks, and for PEP to be effective, it must be taken for at least 28 days. Choosing a regimen that will lead to the fewest missed doses and preparing for side effects (including what to do if they occur) is important. It's also necessary to check for any interactions with other drugs, including over-the-counter and street drugs.
The final step is to follow up with another HIV antibody test in four to six weeks. If that's negative, another test should be taken three months after the exposure to confirm that infection did not occur.
PrEP PEP is intended for rare, one-time exposures -- not for repeated use. For people who are exposed to HIV on a regular basis, a more controversial approach is being studied: the use of HIV meds to prevent infection before exposure. Called PrEP, for pre-exposure prophylaxis, it is based on the common practice of using antiretrovirals to prevent HIV transmission in pregnancy.
Current PrEP studies are using either Viread (tenofovir) or Truvada (tenofovir plus emtricitabine). These products were chosen because they are taken once daily, can be taken without food, and have strong safety records, limited side effects, and favorable resistance profiles. In addition, animal studies have shown that Viread and Truvada can reduce the risk of transmission of simian immunodeficiency virus (SIV) in monkeys. SIV is a virus commonly used in animal research in the hopes that it mirrors HIV infection in humans. But results have been mixed: some studies have found that PrEP in monkeys prevented transmission of SIV, while others found that PrEP only delayed transmission. And, of course, humans may not respond in the same way.
A study presented last month at the 16th International HIV Drug Resistance Workshop found that infusions of Truvada given 2 hours before and 24 hours after exposure prevented SIV infection in all of the six monkeys tested. Once again, we don't know if this will translate to HIV exposure in humans. (All PrEP trials to date have studied the drugs taken as pills once a day, not as infusions just before and after exposure.)
False Starts Four PrEP trials have been stopped before completion for very different reasons. Studies in Cambodia and Cameroon were stopped when activists protested that adequate safer sex counseling was not being provided and that little or no planning was in place to provide healthcare for those who seroconverted during the trial. The Malawi Ministry of Health ended a trial because of concerns that widespread use of tenofovir could complicate its use as an HIV treatment, and a trial in Nigeria was shut down due to questions about trial sites' capacity to conduct the study.
Questions have also been raised about the populations being studied. We know from experience in countries like Thailand that government enforcement of condom use in brothels can dramatically lower HIV infection rates. So is it ethical to conduct studies in sex workers when we already have a method proven to work? In particular, is it ethical to conduct studies in injection drug users in countries where clean needles are not provided by the government? These concerns and others have been the subject of heated debate.
First Results After years of waiting, the first results of a PrEP study were presented at the International AIDS Conference in Toronto in 2006. A study in Ghana enrolled 936 HIV-negative women, half of whom took Viread and half placebo. The results showed that two of the women taking Viread and six of the women taking placebo seroconverted. But these results were not statistically significant because the rigorous safer sex education done by the trial sites led to a decrease in the number of new partners and an impressive increase in self-reported condom use during the last reported sexual encounter -- from 52% to 94%! It may be that trials that are conducted ethically (that is, with proper counseling) will lead to too few seroconversions to yield useful results.
Ongoing Trials In Thailand, the CDC is conducting a study of once-daily Viread in 2,000 HIV-negative injection drug users. The trial is being conducted in collaboration with the Thailand Ministry of Public Health at 17 drug-treatment clinics in Bangkok. But the Thai government, like that in the U.S., does not provide clean needles for drug users, and concerns have been raised about the ethics of testing an unproven prevention method when a proven intervention is not also made available.
The CDC is also conducting a trial with the Botswana Ministry of Health of once-daily Truvada. 1,200 HIV-negative heterosexual men and women aged 18 to 29 are being recruited at HIV counseling and testing centers, sexually transmitted disease and family planning clinics, youth organizations, and community events. The trial had originally been planned to study Viread alone, and had already enrolled 71 people before there was evidence to support trials of Truvada. Researchers therefore will continue to follow those participants to obtain data on the safety of Viread alone.
In the U.S., the CDC is studying once-daily Viread in collaboration with the San Francisco Department of Public Health, the AIDS Research Consortium of Atlanta, and Fenway Community Health in Boston. A variety of recruitment techniques, including outreach and referrals through clinicians and community-based service organizations, are being used to enroll 400 HIV-negative men who have sex with men (MSM) who have had anal intercourse during the past year. To reflect the demographics of the U.S. HIV epidemic, a substantial number of the participants will be MSM of color.
Two groups in the U.S. study will take either Viread or placebo, and two other groups will do the same but after waiting nine months after enrollment. This design will allow researchers to compare risk behaviors among persons who are taking a daily pill and those who are not. This analysis will be critical to understanding the potential impact of a daily drug regimen on HIV risk behavior. Because the number of people in the trial is comparatively small, it will study only the safety of this approach, not its effectiveness.
The National Institutes of Health is preparing a safety and efficacy trial of Truvada PrEP in 1,400 MSM in Peru and Ecuador, and the CDC is in the planning stages for a U.S. study of the safety of Truvada PrEP. (For details on current PrEP studies, visit prepwatch.org.)
Other Issues There have been concerns that people may use PrEP before studies are complete, thinking they are protecting themselves from HIV. Rumors abound that some gay men are already using PrEP, including a "new cocktail" at sex parties called "MTV" (Meth, Tenofovir, and Viagra). But a CDC survey given at gay pride events in 2005 showed that out of 397 HIV-negative gay men, only one person had used PrEP, while five had used PEP. Almost 19% said they had heard of PrEP, indicating that though the concept is somewhat known, its use is not widespread.
If PrEP is proven effective, understanding its impact on HIV risk behaviors will be critical. One of the greatest risks is that people will reduce their use of proven prevention strategies. Because no single strategy will likely be 100% effective, reducing transmission will require integrating all available methods -- both biomedical and behavioral. During trials, all participants must receive state-of-the-art HIV risk-reduction counseling and other proven HIV prevention interventions.
Even if these trials demonstrate that PrEP can reduce HIV transmission, it is equally important to understand whether persons at risk will be willing and able to maintain consistent use of a daily drug. These trials will therefore closely examine participants' adherence to, and acceptance of, daily drug use.
Drug resistance will also need to be addressed during trials. Unlike PEP, which has been so effective that developing resistance has not appeared to be a problem, it is unclear how often resistance will develop if PrEP fails and a person becomes infected while taking Viread alone. Similarly, while the risk of drug-resistant virus will likely be lower in trials of Truvada, which contains two drugs, it will be important to assess any resistance that emerges to either drug.
Several study procedures have been designed to minimize the risk of resistance among any individuals who become infected despite receiving PrEP. It is hoped that regular HIV testing with a rapid HIV test and immediate discontinuation of study pills if participants become infected will lower any risk of a resistant virus emerging. In addition, HIV resistance testing will be provided to all persons infected during the trial. These data will provide important information on the degree to which resistance occurs and will help guide treatment decisions as infected persons are referred to treatment and care.
Community Response Community activists are balancing two contradictory needs. Advocacy is needed to ensure these new prevention ideas are funded appropriately and tested ethically. But it's important not to raise expectations for interventions that may not work, that may prove no more popular than condoms, or that may do harm if used inappropriately.
And PrEP raises some particularly challenging issues of access. Health care providers will need to ensure that PrEP is used before exposure, not after infection, or it could lead to drug-resistant HIV. And exactly who would be prescribed PrEP? Would people be required to prove they're "high risk," and will that lead to their being stigmatized? Will it be available through questionable websites, like Viagra? If it is found to be effective, will ineffective quick fixes like "MTV" become rampant?
It's important to remember that if PrEP is found to be effective, it will need to be a part of a comprehensive HIV prevention program that includes education, empowerment, and proven risk-reduction behaviors. At the same time, after 25 years of HIV, many people are clearly hoping for something other than a lifetime of rubber-insulated sex.
Luis Scaccabarrozzi and Mark Milano are editors of ACRIA Update.
pep and the worst year of my life. (PEP AND THE NEED FOR HIV SPECIALIST) Jul 13, 2008
I'm a bit nervous because I just took PEP and I don't know what the side effects are so maybe you can help out with it.
I've been having pains in my right abdomen for about a month now but my liver enzymes are normal. I'm still a bit scared because it is where my liver is.
Yesterday, I has receptive anal sex with a stranger. I put a condom on him and he was doing what he was doing. Then he said, I THINK SOME ONES COMING, So I look around, there was nobody there and looked behind me. Saw that the condom with lube was on the floor and his zipper was zipped up. Didn't think anything of it. Went home and pooped. I saw a glob of his semen in the toilet and was going to kill myself.
My possible exposure before this one was 4 months ago. It was anal receptive without condom with a guy I barely knew who I can't get in touch with. I came down with flu symptoms and was told to test at 3 months and then 6 months and then a year because I got really sick.
So my result was negative today before I started pep. I wanted to know if my testing window period will change for the sexual encounter that took place 4 months ago or should I trust in a 4 month negative??????
PEP treatment is 1 month.
When should I test again.
Should I stop taking the pep?
Does pep have hiv in it that will effect me if I have previously been exposed(4 months ago), ruining my chances of being negative?
I've had the worst luck any guy can have. I didn't have sex for 4 months and the one day I decided to cruise, I got violated.
Will pep have a bad effect on me if I am infected and don't know it from the 4 month issue?
I know that you're the only one that can answer these questions for me.
Response from Dr. Frascino
Why would you think I am the only one who could answer your questions! Your questions are not uncommon or particularly challenging. Any HIV specialist should be able to help. I'm a bit concerned by your first statement, ". . . I just took PEP and I don't know what the side effects are . . . ." The prescribing physician (hopefully an HIV specialist) should have explained potential side effects at the time the medications were recommended. I can't specifically answer this question, because side effects are different from person to person and also the range of potential side effects differs depending on which antiretroviral medications are in the PEP regimen. I'm also concerned about several of your other questions, such as "Does PED have HIV in it?" Questions like this demonstrate a profound lack of understanding of post-exposure prophylaxis and antiretroviral therapy. (The brief response is no, of course these medications do not contain HIV!)
Your multiple concerns clearly demonstrate why I strongly recommend that all folks who have had an HIV exposure significant enough to warrant PEP have an HIV specialist involved in their care. The HIV specialist will:
1. Evaluate and document the HIV risk exposure.
2. Recommend PEP if warranted.
3. If PEP has already been started, the HIV specialist will revise, optimize or suggest discontinuation of the PEP regimen as indicated.
4. Evaluate and manage all PEP-related side effects and toxicities.
5. Evaluate all symptoms, including potential acute retroviral syndrome symptoms, occurring during the course of PEP therapy.
6. Arrange for and interpret post-PEP HIV testing.
My advice to you is to contact an HIV specialist. He or she will specifically address all your concerns in detail. I would also suggest that you be a bit more discerning regarding your sexual partners. When that last jerk said "I THINK SOME ONES COMING," apparently he was talking about himself! If he managed to ditch the condom without your realizing it, you really need to pay more attention to "what he is doing while he's doing what he's doing," particularly when he's "doing" you!
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